ds_metrics[ /ds_metrics= 0..17] (Type is Int8)

attributes
- long_name: Metrics (Type is String)
- units: 1 (Type is String)
- source: Dim Scale (Type is String)
- valid_min: 1 (Type is Int8)
- valid_max: 18 (Type is Int8)
- contentType: referenceInformation (Type is String)
- description: Dimension scale for metrics. (Type is String)
- flag_meanings: metrics1 metrics2 metrics3 metrics4 metrics5 metrics6 metrics7 metrics8 metrics9 metrics10 metrics11 metrics12 metrics13 metrics14 metrics15 metrics16 metrics17 metrics18 (Type is String)
- flag_values: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 (Type is Int8)

ds_surf_type[ /ds_surf_type= 0..4] (Type is Int32)

attributes
- long_name: Surface Type Dimension Scale (Type is String)
- units: 1 (Type is String)
- source: Dim Scale (Type is String)
- valid_min: 1 (Type is Int32)
- valid_max: 5 (Type is Int32)
- contentType: auxiliaryInformation (Type is String)
- description: Dimension scale indexing the surface type array. Index=1 corresponds to Land; index = 2 corresponds to Ocean; Index = 3 corresponds to SeaIce; Index=4 corresponds to LandIce; Index=5 corresponds to InlandWater (Type is String)
- flag_meanings: land ocean seaice landice inland_water (Type is String)
- flag_values: 1, 2, 3, 4, 5 (Type is Int32)

ds_geosegments[ /ds_geosegments= 0..4] (Type is Int8)

attributes
- long_name: Geosegments (Type is String)
- units: 1 (Type is String)
- source: Dim Scale (Type is String)
- valid_min: 1 (Type is Int8)
- valid_max: 5 (Type is Int8)
- contentType: auxiliaryInformation (Type is String)
- description: Dimension scale for geosegments within land segments. (Type is String)
- flag_meanings: geosegments1 geosegments2 geosegments3 geosegments4 geosegments5 (Type is String)
- flag_values: 1, 2, 3, 4, 5 (Type is Int8)

orbit_info(Type is Group)

attributes
- description: Contains orbit information. (Type is String)
- data_rate: Varies. Data are only provided when one of the stored values (besides time) changes. (Type is String)

Dimensions: [ /orbit_info/crossing_time = 0..0 ] [ /orbit_info/sc_orient_time = 0..0 ]

crossing_time[ /orbit_info/crossing_time= 0..0] (Type is Float64)
- attributes
  - long_name: Ascending Node Crossing Time (Type is String)
  - standard_name: time (Type is String)
  - units: seconds since 2018-01-01 (Type is String)
  - source: POD/PPD (Type is String)
  - contentType: referenceInformation (Type is String)
  - description: The time, in seconds since the ATLAS SDP GPS Epoch, at which the ascending node crosses the equator. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
sc_orient_time[ /orbit_info/sc_orient_time= 0..0] (Type is Float64)
- attributes
  - long_name: Time of Last Spacecraft Orientation Change (Type is String)
  - standard_name: time (Type is String)
  - units: seconds since 2018-01-01 (Type is String)
  - source: POD/PPD (Type is String)
  - contentType: referenceInformation (Type is String)
  - description: The time of the last spacecraft orientation change between forward, backward and transitional flight modes, expressed in seconds since the ATLAS SDP GPS Epoch. ICESat-2 is considered to be flying forward when the weak beams are leading the strong beams; and backward when the strong beams are leading the weak beams. ICESat-2 is considered to be in transition while it is maneuvering between the two orientations. Science quality is potentially degraded while in transition mode. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
cycle_number[ /orbit_info/crossing_time= 0..0] (Type is Int8)
- attributes
  - long_name: Cycle Number (Type is String)
  - units: 1 (Type is String)
  - source: Operations (Type is String)
  - valid_min: 0 (Type is Int8)
  - valid_max: 50 (Type is Int8)
  - contentType: referenceInformation (Type is String)
  - description: A count of the number of exact repeats of this reference orbit. (Type is String)
  - coordinates: crossing_time (Type is String)
rgt[ /orbit_info/crossing_time= 0..0] (Type is Int16)
- attributes
  - long_name: Reference Ground track (Type is String)
  - units: 1 (Type is String)
  - source: POD/PPD (Type is String)
  - valid_min: 1 (Type is Int16)
  - valid_max: 1387 (Type is Int16)
  - contentType: referenceInformation (Type is String)
  - description: The reference ground track (RGT) is the track on the earth at which a specified unit vector within the observatory is pointed. Under nominal operating conditions, there will be no data collected along the RGT, as the RGT is spanned by GT3 and GT4. During slews or off-pointing, it is possible that ground tracks may intersect the RGT. The ICESat-2 mission has 1387 RGTs. (Type is String)
  - coordinates: crossing_time (Type is String)
lan[ /orbit_info/crossing_time= 0..0] (Type is Float64)
- attributes
  - long_name: Ascending Node Longitude (Type is String)
  - units: degrees_east (Type is String)
  - source: POD/PPD (Type is String)
  - valid_min: -180. (Type is Float64)
  - valid_max: 180. (Type is Float64)
  - contentType: referenceInformation (Type is String)
  - description: Longitude at the ascending node crossing. (Type is String)
  - coordinates: crossing_time (Type is String)
bounding_polygon_lat1[ 0..22] (Type is Float64)
- attributes
  - long_name: Polygon1 Latitude (Type is String)
  - units: degrees_north (Type is String)
  - source: geo_poly (Type is String)
  - valid_min: -90. (Type is Float64)
  - valid_max: 90. (Type is Float64)
  - contentType: auxiliaryInformation (Type is String)
  - description: Latitude values for the first out of two possible bounding polygons (Type is String)
orbit_number[ /orbit_info/crossing_time= 0..0] (Type is UInt16)
- attributes
  - long_name: Orbit Number (Type is String)
  - units: 1 (Type is String)
  - source: Operations (Type is String)
  - valid_min: 1 (Type is UInt16)
  - valid_max: 65000 (Type is UInt16)
  - contentType: referenceInformation (Type is String)
  - description: Unique identifying number for each planned ICESat-2 orbit. (Type is String)
  - coordinates: crossing_time (Type is String)
bounding_polygon_lon1[ 0..22] (Type is Float64)
- attributes
  - long_name: Polygon1 Longitude (Type is String)
  - units: degrees_east (Type is String)
  - source: geo_poly (Type is String)
  - valid_min: -180. (Type is Float64)
  - valid_max: 180. (Type is Float64)
  - contentType: auxiliaryInformation (Type is String)
  - description: Longitude values for the first out of two possible bounding polygons (Type is String)
sc_orient[ /orbit_info/sc_orient_time= 0..0] (Type is Int8)
- attributes
  - long_name: Spacecraft Orientation (Type is String)
  - units: 1 (Type is String)
  - source: POD/PPD (Type is String)
  - valid_min: 0 (Type is Int8)
  - valid_max: 2 (Type is Int8)
  - contentType: referenceInformation (Type is String)
  - description: This parameter tracks the spacecraft orientation between forward, backward and transitional flight modes. ICESat-2 is considered to be flying forward when the weak beams are leading the strong beams; and backward when the strong beams are leading the weak beams. ICESat-2 is considered to be in transition while it is maneuvering between the two orientations. Science quality is potentially degraded while in transition mode. (Type is String)
  - coordinates: sc_orient_time (Type is String)
  - flag_meanings: backward forward transition (Type is String)
  - flag_values: 0, 1, 2 (Type is Int8)

METADATA(Type is Group)

attributes
- description: ISO19115 Structured Metadata Represented within HDF5 (Type is String)

gt1r(Type is Group)

attributes
- atlas_pce: pce1 (Type is String)
- atlas_beam_type: weak (Type is String)
- atlas_spot_number: 2 (Type is String)
- sc_orientation: Backward (Type is String)
- groundtrack_id: gt1r (Type is String)
- atmosphere_profile: profile_1 (Type is String)

gt2r(Type is Group)

attributes
- atlas_pce: pce2 (Type is String)
- atlas_beam_type: weak (Type is String)
- groundtrack_id: gt2r (Type is String)
- atmosphere_profile: profile_2 (Type is String)
- atlas_spot_number: 4 (Type is String)
- sc_orientation: Backward (Type is String)

gt1l(Type is Group)

attributes
- atlas_pce: pce1 (Type is String)
- atlas_beam_type: strong (Type is String)
- groundtrack_id: gt1l (Type is String)
- atmosphere_profile: profile_1 (Type is String)
- atlas_spot_number: 1 (Type is String)
- sc_orientation: Backward (Type is String)

quality_assessment(Type is Group)

attributes
- description: Contains quality assessment data. This may include QA counters, QA along-track data and/or QA summary data. (Type is String)

qa_granule_fail_reason[ 0..0] (Type is Int32)
- attributes
  - long_name: Granule Failure Reason (Type is String)
  - units: 1 (Type is String)
  - source: Operations (Type is String)
  - valid_min: 0 (Type is Int32)
  - valid_max: 5 (Type is Int32)
  - contentType: qualityInformation (Type is String)
  - description: Flag indicating granule failure reason. 0=no failure; 1=processing error; 2=Insufficient output data was generated; 3=TBD Failure; 4=TBD_Failure; 5=other failure. (Type is String)
  - flag_meanings: no_failure PROCESS_ERROR INSUFFICIENT_OUTPUT failure_3 failure_4 OTHER_FAILURE (Type is String)
  - flag_values: 0, 1, 2, 3, 4, 5 (Type is Int32)
qa_granule_pass_fail[ 0..0] (Type is Int32)
- attributes
  - long_name: Granule Pass Flag (Type is String)
  - units: 1 (Type is String)
  - source: Operations (Type is String)
  - valid_min: 0 (Type is Int32)
  - valid_max: 1 (Type is Int32)
  - contentType: qualityInformation (Type is String)
  - description: Flag indicating granule quality. 0=granule passes automatic QA. 1=granule fails automatic QA. (Type is String)
  - flag_meanings: PASS FAIL (Type is String)
  - flag_values: 0, 1 (Type is Int32)

gt3l(Type is Group)

attributes
- atlas_pce: pce3 (Type is String)
- atlas_beam_type: strong (Type is String)
- groundtrack_id: gt3l (Type is String)
- atmosphere_profile: profile_3 (Type is String)
- atlas_spot_number: 5 (Type is String)
- sc_orientation: Backward (Type is String)

gt2l(Type is Group)

attributes
- atlas_pce: pce2 (Type is String)
- atlas_beam_type: strong (Type is String)
- groundtrack_id: gt2l (Type is String)
- atmosphere_profile: profile_2 (Type is String)
- atlas_spot_number: 3 (Type is String)
- sc_orientation: Backward (Type is String)

ancillary_data(Type is Group)

attributes
- data_rate: Data within this group pertain to the granule in its entirety. (Type is String)
- description: Contains information ancillary to the data product. This may include product characteristics, instrument characteristics and/or processing constants. (Type is String)

gt3r(Type is Group)

attributes
- atlas_pce: pce3 (Type is String)
- atlas_beam_type: weak (Type is String)
- groundtrack_id: gt3r (Type is String)
- atmosphere_profile: profile_3 (Type is String)
- atlas_spot_number: 6 (Type is String)
- sc_orientation: Backward (Type is String)

Actions	Download Encoding:
Data URL

Global Attributes	View/Hide short_name: ATL08 (Type is String) level: L3A (Type is String) description: This data set (ATL08) contains along-track heights above the WGS84 ellipsoid (ITRF2014 reference frame) for the ground and canopy surfaces. The canopy and ground surfaces are processed in fixed 100 m data segments, which typically contain more than 100 sig (Type is String) Conventions: CF-1.6 (Type is String) contributor_name: Thomas A Neumann (thomas.neumann@nasa.gov), Thorsten Markus (thorsten.markus@nasa.gov), Suneel Bhardwaj (suneel.bhardwaj@nasa.gov) David W Hancock III (david.w.hancock@nasa.gov) (Type is String) contributor_role: Instrument Engineer, Investigator, Principle Investigator, Data Producer, Data Producer (Type is String) date_type: UTC (Type is String) featureType: trajectory (Type is String) geospatial_lat_units: degrees_north (Type is String) geospatial_lon_units: degrees_east (Type is String) granule_type: ATL08 (Type is String) identifier_product_doi_authority: http://dx.doi.org (Type is String) license: Data may not be reproduced or distributed without including the citation for this product included in this metadata. Data may not be distributed in an altered form without the written permission of the ICESat-2 Science Project Office at NASA/GSFC. (Type is String) naming_authority: http://dx.doi.org (Type is String) spatial_coverage_type: Horizontal (Type is String) standard_name_vocabulary: CF-1.6 (Type is String) time_type: CCSDS UTC-A (Type is String) date_created: 2025-06-24T16:29:22.000000Z (Type is String) hdfversion: HDF5 1.14.4 (Type is String) history: 2025-06-24T16:29:22.000000Z;356bd535-f3e2-3aeb-b91b-bf93800a1093;Created by PGE atlas_l3a_ld Version 4.1 (Type is String) identifier_file_uuid: 356bd535-f3e2-3aeb-b91b-bf93800a1093 (Type is String) identifier_product_format_version: 4.1 (Type is String) time_coverage_duration: 510. (Type is Float64) time_coverage_end: 2020-07-16T20:31:21.000000Z (Type is String) time_coverage_start: 2020-07-16T20:22:51.000000Z (Type is String) geospatial_lat_min: 27.000105159300347 (Type is Float64) geospatial_lon_min: 7.2780104575842639 (Type is Float64) geospatial_lat_max: 59.504771275065515 (Type is Float64) geospatial_lon_max: 11.868865242765473 (Type is Float64) publisher_name: NSIDC DAAC > NASA National Snow and Ice Data Center Distributed Active Archive Center (Type is String) publisher_email: nsidc@nsidc.org (Type is String) publisher_url: http://nsidc.org/daac/ (Type is String) title: ATLAS/ICESat-2 L3A Land and Vegetation Height Quick Look (Type is String) identifier_product_type: ATL08 (Type is String) identifier_product_doi: doi:10.5067/ATLAS/ATL08.007 (Type is String) institution: National Aeronautics and Space Administration (NASA) (Type is String) creator_name: GSFC I-SIPS > ICESat-2 Science Investigator-led Processing System (Type is String) summary: The purpose of ATL08 is to provide along-track land/canopy heights and associated statistics. (Type is String) keywords: EARTH SCIENCE > BIOSPHERE > VEGETATION > NONE > NONE > NONE > NONE (Type is String) keywords_vocabulary: NASA/GCMD Science Keywords (Type is String) citation: Cite these data in publications as follows: The data used in this study were produced by the ICESat-2 Science Project Office at NASA/GSFC. The data archive site is the NASA National Snow and Ice Data Center Distributed Active Archive Center. (Type is String) processing_level: 3A (Type is String) references: http://nsidc.org/data/icesat2/data.html (Type is String) project: ICESat-2 > Ice, Cloud, and land Elevation Satellite-2 (Type is String) instrument: ATLAS > Advanced Topographic Laser Altimeter System (Type is String) platform: ICESat-2 > Ice, Cloud, and land Elevation Satellite-2 (Type is String) source: Spacecraft (Type is String) build_dmrpp_metadata created: 2025-12-22T18:06:46Z (Type is String) build_dmrpp: 3.21.1 (Type is String) bes: 3.21.1 (Type is String) libdap: libdap-3.21.1 (Type is String) invocation: build_dmrpp -f /Users/myang6/Desktop/tmp-amazon-nasa-files/ATL08_20200716202251_03280806_007_01.h5 -r ATL08_20200716202251_03280806_007_01.h5.dmr -u OPeNDAP_DMRpp_DATA_ACCESS_URL -M (Type is String)

Global Dimensions	View/Hide [ /ds_metrics = 0..17 ] [ /ds_surf_type = 0..4 ] [ /ds_geosegments = 0..4 ]

Variables	ds_metrics[ /ds_metrics= 0..17] (Type is Int8) attributes long_name: Metrics (Type is String) units: 1 (Type is String) source: Dim Scale (Type is String) valid_min: 1 (Type is Int8) valid_max: 18 (Type is Int8) contentType: referenceInformation (Type is String) description: Dimension scale for metrics. (Type is String) flag_meanings: metrics1 metrics2 metrics3 metrics4 metrics5 metrics6 metrics7 metrics8 metrics9 metrics10 metrics11 metrics12 metrics13 metrics14 metrics15 metrics16 metrics17 metrics18 (Type is String) flag_values: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 (Type is Int8) ds_surf_type[ /ds_surf_type= 0..4] (Type is Int32) attributes long_name: Surface Type Dimension Scale (Type is String) units: 1 (Type is String) source: Dim Scale (Type is String) valid_min: 1 (Type is Int32) valid_max: 5 (Type is Int32) contentType: auxiliaryInformation (Type is String) description: Dimension scale indexing the surface type array. Index=1 corresponds to Land; index = 2 corresponds to Ocean; Index = 3 corresponds to SeaIce; Index=4 corresponds to LandIce; Index=5 corresponds to InlandWater (Type is String) flag_meanings: land ocean seaice landice inland_water (Type is String) flag_values: 1, 2, 3, 4, 5 (Type is Int32) ds_geosegments[ /ds_geosegments= 0..4] (Type is Int8) attributes long_name: Geosegments (Type is String) units: 1 (Type is String) source: Dim Scale (Type is String) valid_min: 1 (Type is Int8) valid_max: 5 (Type is Int8) contentType: auxiliaryInformation (Type is String) description: Dimension scale for geosegments within land segments. (Type is String) flag_meanings: geosegments1 geosegments2 geosegments3 geosegments4 geosegments5 (Type is String) flag_values: 1, 2, 3, 4, 5 (Type is Int8) orbit_info(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: crossing_time, sc_orient_time (Type is String) description: Contains orbit information. (Type is String) data_rate: Varies. Data are only provided when one of the stored values (besides time) changes. (Type is String) Dimensions: [ /orbit_info/crossing_time = 0..0 ] [ /orbit_info/sc_orient_time = 0..0 ] crossing_time[ /orbit_info/crossing_time= 0..0] (Type is Float64) attributes long_name: Ascending Node Crossing Time (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: POD/PPD (Type is String) contentType: referenceInformation (Type is String) description: The time, in seconds since the ATLAS SDP GPS Epoch, at which the ascending node crosses the equator. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) sc_orient_time[ /orbit_info/sc_orient_time= 0..0] (Type is Float64) attributes long_name: Time of Last Spacecraft Orientation Change (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: POD/PPD (Type is String) contentType: referenceInformation (Type is String) description: The time of the last spacecraft orientation change between forward, backward and transitional flight modes, expressed in seconds since the ATLAS SDP GPS Epoch. ICESat-2 is considered to be flying forward when the weak beams are leading the strong beams; and backward when the strong beams are leading the weak beams. ICESat-2 is considered to be in transition while it is maneuvering between the two orientations. Science quality is potentially degraded while in transition mode. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) cycle_number[ /orbit_info/crossing_time= 0..0] (Type is Int8) attributes long_name: Cycle Number (Type is String) units: 1 (Type is String) source: Operations (Type is String) valid_min: 0 (Type is Int8) valid_max: 50 (Type is Int8) contentType: referenceInformation (Type is String) description: A count of the number of exact repeats of this reference orbit. (Type is String) coordinates: crossing_time (Type is String) rgt[ /orbit_info/crossing_time= 0..0] (Type is Int16) attributes long_name: Reference Ground track (Type is String) units: 1 (Type is String) source: POD/PPD (Type is String) valid_min: 1 (Type is Int16) valid_max: 1387 (Type is Int16) contentType: referenceInformation (Type is String) description: The reference ground track (RGT) is the track on the earth at which a specified unit vector within the observatory is pointed. Under nominal operating conditions, there will be no data collected along the RGT, as the RGT is spanned by GT3 and GT4. During slews or off-pointing, it is possible that ground tracks may intersect the RGT. The ICESat-2 mission has 1387 RGTs. (Type is String) coordinates: crossing_time (Type is String) lan[ /orbit_info/crossing_time= 0..0] (Type is Float64) attributes long_name: Ascending Node Longitude (Type is String) units: degrees_east (Type is String) source: POD/PPD (Type is String) valid_min: -180. (Type is Float64) valid_max: 180. (Type is Float64) contentType: referenceInformation (Type is String) description: Longitude at the ascending node crossing. (Type is String) coordinates: crossing_time (Type is String) bounding_polygon_lat1[ 0..22] (Type is Float64) attributes long_name: Polygon1 Latitude (Type is String) units: degrees_north (Type is String) source: geo_poly (Type is String) valid_min: -90. (Type is Float64) valid_max: 90. (Type is Float64) contentType: auxiliaryInformation (Type is String) description: Latitude values for the first out of two possible bounding polygons (Type is String) orbit_number[ /orbit_info/crossing_time= 0..0] (Type is UInt16) attributes long_name: Orbit Number (Type is String) units: 1 (Type is String) source: Operations (Type is String) valid_min: 1 (Type is UInt16) valid_max: 65000 (Type is UInt16) contentType: referenceInformation (Type is String) description: Unique identifying number for each planned ICESat-2 orbit. (Type is String) coordinates: crossing_time (Type is String) bounding_polygon_lon1[ 0..22] (Type is Float64) attributes long_name: Polygon1 Longitude (Type is String) units: degrees_east (Type is String) source: geo_poly (Type is String) valid_min: -180. (Type is Float64) valid_max: 180. (Type is Float64) contentType: auxiliaryInformation (Type is String) description: Longitude values for the first out of two possible bounding polygons (Type is String) sc_orient[ /orbit_info/sc_orient_time= 0..0] (Type is Int8) attributes long_name: Spacecraft Orientation (Type is String) units: 1 (Type is String) source: POD/PPD (Type is String) valid_min: 0 (Type is Int8) valid_max: 2 (Type is Int8) contentType: referenceInformation (Type is String) description: This parameter tracks the spacecraft orientation between forward, backward and transitional flight modes. ICESat-2 is considered to be flying forward when the weak beams are leading the strong beams; and backward when the strong beams are leading the weak beams. ICESat-2 is considered to be in transition while it is maneuvering between the two orientations. Science quality is potentially degraded while in transition mode. (Type is String) coordinates: sc_orient_time (Type is String) flag_meanings: backward forward transition (Type is String) flag_values: 0, 1, 2 (Type is Int8) METADATA(Type is Group) attributes description: ISO19115 Structured Metadata Represented within HDF5 (Type is String) iso_19139_dataset_xml[ 0..0] (Type is String) attributes long_name: ISO 19139 Dataset XML (Type is String) description: ISO 19139 Dataset XML (Type is String) iso_19139_series_xml[ 0..0] (Type is String) attributes long_name: ISO 19139 Series XML (Type is String) description: ISO 19139 Series XML (Type is String) AcquisitionInformation(Type is Group) no attributes lidar(Type is Group) attributes pulse_rate: 10000 pps (Type is String) wavelength: 532 nm (Type is String) identifier: ATLAS (Type is String) type: Laser Altimeter (Type is String) description: ATLAS on ICESat-2 determines the range between the satellite and the Earth's surface by measuring the two-way time delay of short pulses of laser light that it transmits in six beams. It is different from previous operational ice-sheet altimeters in that it is a photon-counting LIDAR. ATLAS records a set of arrival times for individual photons, which are then analyzed to derive surface, vegetation, and cloud properties. ATLAS has six beams arranged in three pairs, so that it samples each of three reference pair tracks with a pair of beams; ATLAS transmits pulses at 10 kHz, giving approximately one pulse every 0.7 m along track; ATLAS's expected pointing control will be better than 90 m RMS. (Type is String) lidarDocument(Type is Group) attributes edition: Pre-Release (Type is String) publicationDate: 12/31/17 (Type is String) title: A document describing the ATLAS instrument will be provided by the ICESat-2 Project Science Office. (Type is String) platform(Type is Group) attributes identifier: ICESat-2 (Type is String) description: Ice, Cloud, and land Elevation Satellite-2 (Type is String) type: Spacecraft (Type is String) platformDocument(Type is Group) attributes edition: 31-Dec-16 (Type is String) publicationDate: 31-Dec-16 (Type is String) title: The Ice, Cloud, and land Elevation Satellite-2 (ICESat-2): Science requirements, concept, and implementation. Thorsten Markus, Tom Neumann, Anthony Martino, Waleed Abdalati, Kelly Brunt, Beata Csatho, Sinead Farrell, Helen Fricker, Alex Gardner, David Harding, Michael Jasinski, Ron Kwok, Lori Magruder, Dan Lubin, Scott Luthcke, James Morison, Ross Nelson, Amy Neuenschwander, Stephen Palm, Sorin Popescu, CK Shum, Bob E. Schutz, Benjamin Smith, Yuekui Yang, Jay Zwally. http://dx.doi.org/10.1016/j.rse.2016.12.029 (Type is String) ProductSpecificationDocument(Type is Group) attributes ShortName: ATL08_SDP (Type is String) characterSet: utf8 (Type is String) language: eng (Type is String) publicationDate: Feb 2020 (Type is String) title: ICESat-2-SIPS-SPEC-4262 - ATLAS Science Algorithm Standard Data Product (SDP) Volume 7 (ATL08). (Type is String) edition: v4.3 (Type is String) SeriesIdentification(Type is Group) attributes maintenanceAndUpdateFrequency: asNeeded (Type is String) maintenanceDate: SET_BY_META (Type is String) VersionID: 007 (Type is String) language: eng (Type is String) characterSet: utf8 (Type is String) pointOfContact: NSIDC DAAC > NASA National Snow and Ice Data Center Distributed Active Archive Center (Type is String) longName: ATLAS/ICESat-2 L3A Land and Vegetation Height Quick Look (Type is String) shortName: ATL08 (Type is String) identifier_product_DOI: doi:10.5067/ATLAS/ATL08.007 (Type is String) revisionDate: 2022-08-09 (Type is String) resourceProviderOrganizationName: National Aeronautics and Space Administration (NASA) (Type is String) abstract: The ICESat-2 ATL08 standard data product contains along-track heights of ground and canopy surface at varying length scales. Where data permits, this includes estimates of canopy height, relative canopy cover, canopy height distributions, surface roughness, surface slope/aspect, and apparent reflectance. (Type is String) purpose: The purpose of ATL08 is to provide along-track land/canopy heights and associated statistics. (Type is String) credit: The software that generates the ATL08 product was designed and implemented within the ICESat-2 Science Investigator-led Processing System at the NASA Goddard Space Flight Center in Greenbelt, Maryland. (Type is String) status: onGoing (Type is String) format: HDF (Type is String) formatVersion: 5 (Type is String) topicCategory: geoscientificInformation (Type is String) mission: ICESat-2 > Ice, Cloud, and land Elevation Satellite-2 (Type is String) DatasetIdentification(Type is Group) attributes spatialRepresentationType: along-track (Type is String) creationDate: 2025-06-24T16:29:22.000000Z (Type is String) uuid: 356bd535-f3e2-3aeb-b91b-bf93800a1093 (Type is String) fileName: ATL08_20200716202251_03280806_007_01.h5 (Type is String) VersionID: 007 (Type is String) language: eng (Type is String) characterSet: utf8 (Type is String) shortName: ATL08 (Type is String) originatorOrganizationName: GSFC I-SIPS > ICESat-2 Science Investigator-led Processing System (Type is String) abstract: The ICESat-2 ATL08 standard data product contains along-track heights of ground and canopy surface at varying length scales. Where data permits, this includes estimates of canopy height, relative canopy cover, canopy height distributions, surface roughness, surface slope/aspect, and apparent reflectance. (Type is String) purpose: The purpose of ATL08 is to provide along-track land/canopy heights and associated statistics. (Type is String) credit: The software that generates the ATL08 product was designed and implemented within the ICESat-2 Science Investigator-led Processing System at the NASA Goddard Space Flight Center in Greenbelt, Maryland. (Type is String) status: onGoing (Type is String) topicCategory: geoscientificInformation (Type is String) Extent(Type is Group) attributes northBoundLatitude: 59.504771275065515 (Type is Float64) eastBoundLongitude: 11.868865242765473 (Type is Float64) southBoundLatitude: 27.000105159300347 (Type is Float64) westBoundLongitude: 7.2780104575842639 (Type is Float64) rangeBeginningDateTime: 2020-07-16T20:22:51.006883Z (Type is String) rangeEndingDateTime: 2020-07-16T20:31:21.602596Z (Type is String) QADatasetIdentification(Type is Group) attributes creationDate: 2025-06-24T17:10:31.000000Z (Type is String) abstract: An ASCII product that contains statistical information on data product results. These statistics enable data producers and users to assess the quality of the data in the data product granule (Type is String) fileName: ATL08_20200716202251_03280806_007_01.qa (Type is String) Lineage(Type is Group) no attributes Control(Type is Group) attributes description: Text-based keyword=value file generated automatically within the ICESat-2 data system that specifies all of the conditions required for each individual run of the software. (Type is String) fileName: CTL_atlas_l3a_ld_019563783.ctl (Type is String) shortName: CNTL (Type is String) version: 1 (Type is String) ANC28(Type is Group) attributes description: DTU Mean Sea Surface re-referenced to the WGS84 ellipsoid. (Type is String) uuid: SET_BY_PGE (Type is String) version: SET_BY_PGE (Type is String) fileName: SET_BY_PGE (Type is String) shortName: SET_BY_PGE (Type is String) ANC14(Type is Group) attributes description: Woody Vegetation Coverage Fraction (Type is String) fileName: ANC14-00_20210831170932_20210601_01.h5 (Type is String) shortName: ANC14 (Type is String) uuid: bb667bc0-93a8-34be-9280-04a2f8436aff (Type is String) version: 20210601 (Type is String) ANC06-02(Type is Group) attributes description: ArcticDEM 32m Digital Elevation Model reformatted into HDF5. (Type is String) fileName: arcticdem32m_20190611_001_01.h5 (Type is String) shortName: ANC06-02 (Type is String) uuid: ce07ef72-0bf4-353b-8475-fb568b029905 (Type is String) version: 20190611 (Type is String) ANC06-03(Type is Group) attributes description: REMA Antarctica 100m Digital Elevation Model filled and reformatted into HDF5 (Type is String) fileName: atl06rema100m_20190628_001_01.h5 (Type is String) shortName: ANC06-03 (Type is String) uuid: 3e0a81bd-bbd5-35fa-b868-3254f9355b7f (Type is String) version: 20190628 (Type is String) ANC25-08(Type is Group) attributes description: HDF5 template file that defines the organization and default content of the product. (Type is String) fileName: ANC25-08_20250523205531_041_01.h5 (Type is String) shortName: ANC25-08 (Type is String) uuid: 9f230450-5edc-399f-8f3c-4522f1910ab3 (Type is String) version: 041 (Type is String) ANC46(Type is Group) attributes description: Urban Flag File (Type is String) fileName: dlr_guf_20210115_001_01.h5 (Type is String) shortName: ANC46 (Type is String) uuid: d555b51c-dcd5-34b1-99c4-e056594cf5b5 (Type is String) version: 20210115 (Type is String) ANC47(Type is Group) attributes description: Permafrost File (Type is String) fileName: ESApermafrost2019_20230918_001_01.nc (Type is String) shortName: ANC47 (Type is String) uuid: 39365b1d-d7cd-38b1-92b2-3d13bdd70ba0 (Type is String) version: 20230918 (Type is String) ANC33(Type is Group) attributes description: Water Mask File (Type is String) fileName: watermask_2000_20180301_001_global.h5 (Type is String) shortName: ANC33 (Type is String) uuid: 1e7d3697-c576-308d-9197-21d827ac21db (Type is String) version: 20180301 (Type is String) ANC18(Type is Group) attributes description: Global Land Cover Classification File (Type is String) fileName: cop_classification_20210603_001_01.h5 (Type is String) shortName: ANC18 (Type is String) uuid: ffb62f02-84be-369e-9840-35328cd2bee8 (Type is String) version: 20210603 (Type is String) ANC38-08(Type is Group) attributes description: ISO 19139 XML file containing DataSet-level metadata information. (Type is String) fileName: ATL08.esdt.dataset.xml (Type is String) shortName: ANC38-08 (Type is String) uuid: 390c9903-9c0d-3b90-9e38-4998fd8b6e13 (Type is String) version: 007 (Type is String) ATL03(Type is Group) attributes description: ICESat-2 ATLAS L2A Global Geolocated Photon data products. (Type is String) fileName: ATL03_20200716202251_03280806_007_01.h5 (Type is String) shortName: ATL03 (Type is String) uuid: 0f256bf6-61e1-31c1-a138-25a971f25418 (Type is String) version: 007 (Type is String) start_cycle: 8 (Type is Int32) end_cycle: 8 (Type is Int32) start_orbit: 10238 (Type is Int32) end_orbit: 10238 (Type is Int32) start_rgt: 328 (Type is Int32) end_rgt: 328 (Type is Int32) start_region: 6 (Type is Int32) end_region: 6 (Type is Int32) start_geoseg: 671053 (Type is Int32) end_geoseg: 852078 (Type is Int32) ATL09(Type is Group) attributes description: ICESat-2 ATLAS L3A atmosphere data products. (Type is String) fileName: ATL09_20200716195119_03280801_007_01.h5 (Type is String) shortName: ATL09 (Type is String) uuid: 19705172-ba3e-3436-80f6-574027939bc7 (Type is String) version: 007 (Type is String) start_cycle: 8 (Type is Int32) end_cycle: 8 (Type is Int32) start_orbit: 10238 (Type is Int32) end_orbit: 10238 (Type is Int32) start_rgt: 328 (Type is Int32) end_rgt: 328 (Type is Int32) start_region: 1 (Type is Int32) end_region: 14 (Type is Int32) start_geoseg: 64 (Type is Int32) end_geoseg: 2007133 (Type is Int32) ANC06-01(Type is Group) attributes description: MERIT 3 arcsec Digital Elevation Model reformatted into HDF5 and re-referenced to the WGS-84 ellipsoid. (Type is String) fileName: merit_3as_20200617_001_01.h5 (Type is String) shortName: ANC06-01 (Type is String) uuid: 3db8ab65-d2ac-37c7-86db-17c762268673 (Type is String) version: 20200617 (Type is String) ANC26-08(Type is Group) attributes description: HDF5 template file that defines the organization and default content of the product metadata. (Type is String) fileName: ANC26-08_20250523205538_041_01.h5 (Type is String) shortName: ANC26-08 (Type is String) uuid: 1d565967-3167-3bee-bee3-ed373776e5b8 (Type is String) version: 041 (Type is String) ANC19(Type is Group) attributes description: TAI to UTC leapsecond file retrieved from ftp://maia.usno.navy.mil/ser7/tai-utc.dat (Type is String) fileName: tai_utc_2017.dat (Type is String) shortName: ANC19 (Type is String) uuid: 7c66d365-278a-31f7-8fe4-9c80e2f012e5 (Type is String) version: 001 (Type is String) ANC36-08(Type is Group) attributes description: ISO 19139 XML file containing Series-level metadata information. (Type is String) fileName: ATL08.esdt.series.xml (Type is String) shortName: ANC36-08 (Type is String) uuid: 8fa6664b-4daf-3f2f-834e-c8911c46ea18 (Type is String) version: 007 (Type is String) ProcessStep(Type is Group) no attributes Browse(Type is Group) attributes processDescription: Browse processing is performed for each granule SIPS produces. The browse utility reads data from the granule and produces browse images as defined in the respective product ATBD. The utility then embeds each browse image into the product within the /Browse group. (Type is String) identifier: atlas_brw (Type is String) softwareVersion: Version 3.1.3 (Type is String) softwareDate: Apr 8 2025 (Type is String) softwareTitle: Creates ATLAS HDF5 browse files (Type is String) runTimeParameters: CTL_atlas_l3a_ld_019563783.ctl (Type is String) stepDateTime: 2025-06-24T17:10:41.000000Z (Type is String) Metadata(Type is Group) attributes processDescription: Metadata information is processed by the metadata utility for each granule produced by SIPS. During PGE processing, dynamic metadata are written to the product. Additional static information is provided with the metadata template. The metadata utility reads ISO Dataset and Series metadata files and updates the product with static information from within those files. The utility then merges the static and dynamic metadata to creates output ISO19139 Dataset and Series XML files. Finally the utility reads the ISO19139 Dataset and Series XML files into memory and stores the textual representations as attributes attached to the /METADATA group. (Type is String) identifier: atlas_meta (Type is String) softwareVersion: Version 5.1.3 (Type is String) softwareDate: Apr 8 2025 (Type is String) softwareTitle: Creates ATLAS XML metadata files (Type is String) runTimeParameters: CTL_atlas_l3a_ld_019563783.ctl (Type is String) stepDateTime: 2025-06-24T17:10:58.000000Z (Type is String) PGE(Type is Group) attributes ATBDDate: 01/17/2020 (Type is String) ATBDTitle: Algorithm Theoretical Basis Document (ATBD) for Land - Vegetation Along-Track Products (ATL08) (Type is String) ATBDVersion: v.3 (Type is String) documentDate: Feb 2020 (Type is String) documentation: ATLAS Science Algorithm Software Design Description (SDD) - Volume 12 (atlas_l3a_ld) (Type is String) processDescription: Determines heights of ground and canopy surface. Where data permits, includes estimates of canopy height, relative canopy cover, canopy height distributions, surface roughness, surface slope/aspect and apparent reflectance. (Type is String) identifier: atlas_l3a_ld (Type is String) softwareVersion: Version 4.1 (Type is String) softwareDate: Apr 8 2025 (Type is String) softwareTitle: ASAS L3A Land PGE (Type is String) runTimeParameters: CTL_atlas_l3a_ld_019563783.ctl (Type is String) stepDateTime: 2025-06-24T16:29:22.000000Z (Type is String) QA(Type is Group) attributes processDescription: QA processing is performed by an external utility on each granule produced by SIPS. The utility reads the granule, performs both generic and product-specific quality-assessment calculations, and writes a text-based quality assessment report. The name and creation data of this report are identified within the QADatasetIdentification metadata (Type is String) identifier: atl08_qa_util (Type is String) softwareVersion: Version 4.1 (Type is String) softwareDate: Apr 8 2025 (Type is String) softwareTitle: ATL08 QA Utility (Type is String) runTimeParameters: CTL_atlas_l3a_ld_019563783.ctl (Type is String) stepDateTime: 2025-06-24T17:10:31.000000Z (Type is String) gt1r(Type is Group) attributes atlas_pce: pce1 (Type is String) atlas_beam_type: weak (Type is String) atlas_spot_number: 2 (Type is String) sc_orientation: Backward (Type is String) groundtrack_id: gt1r (Type is String) atmosphere_profile: profile_1 (Type is String) land_segments(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) description: Contains data categorized as land at 100 meter intervals. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) Dimensions: [ /gt1r/land_segments/delta_time = 0..19082 ] longitude[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes long_name: longitude (Type is String) standard_name: longitude (Type is String) units: degrees (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) valid_min: -180. (Type is Float32) valid_max: 180. (Type is Float32) contentType: modelResult (Type is String) description: Longitude of the center-most signal photon within each segment. (Type is String) coordinates: delta_time latitude (Type is String) latitude[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes long_name: latitude (Type is String) standard_name: latitude (Type is String) units: degrees (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) valid_min: -90. (Type is Float32) valid_max: 90. (Type is Float32) contentType: modelResult (Type is String) description: Latitude of the center-most signal photon within each segment. (Type is String) coordinates: delta_time longitude (Type is String) delta_time[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float64) attributes long_name: mean_pass_time (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) contentType: referenceInformation (Type is String) description: Mean time for the segment in number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: latitude longitude (Type is String) rgt[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int16) attributes long_name: reference ground track (Type is String) units: 1 (Type is String) source: Operations (Type is String) valid_min: 1 (Type is Int16) valid_max: 1387 (Type is Int16) contentType: referenceInformation (Type is String) description: The reference ground track (RGT) is the track on the earth at which a specified unit vector within the observatory is pointed. Under nominal operating conditions, there will be no data collected along the RGT, as the RGT is spanned by GT3 and GT4. During slews or off-pointing, it is possible that ground tracks may intersect the RGT. The ICESat-2 mission has 1387 RGTs. (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_flag[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int8) attributes long_name: dem source flag (Type is String) units: 1 (Type is String) source: Atmosphere ATBD (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: referenceInformation (Type is String) description: Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=Global, 3=MSS, 4=Antarctic. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: none arctic global mss antarctic Undetermined (Type is String) flag_values: 0, 1, 2, 3, 4, 127 (Type is Int8) msw_flag[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int8) attributes long_name: multiple scattering warning flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: qualityInformation (Type is String) description: Multiple Scattering Warning flag. If no layers were detected, then msw_flag = 0. If blowing snow is detected and its estimated optical depth is greater than or equal to 0.5, then msw_flag = 5. If the blowing snow optical depth is less than 0.5, then msw_flag = 4. If no blowing snow is detected but there are cloud or aerosol layers detected, the msw_flag assumes values of 1 to 3 based on the height of the bottom of the lowest layer: < 1 km, msw_flag = 3; 1-3 km, msw_flag = 2; > 3km, msw_flag = 1. A value of 127 indicates that the signal to noise of the data was too low to reliably ascertain the presence of cloud or blowing snow. We expect values of 127 to occur only during daylight. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: cannot_determine no_layers layer_gt_3km layer_between_1_and_3_km layer_lt_1km blow_snow_od_lt_0.5 blow_snow_od_gt_0.5 (Type is String) flag_values: 127, 0, 1, 2, 3, 4, 5 (Type is Int8) permafrost_prob[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: permafrost probaility (Type is String) standard_name: permafrost_prob (Type is String) units: percent (Type is String) source: ESA CCI, ANC47 (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: referenceInformation (Type is String) description: Permafrost probability (0 - 100) derived via percent of permafrost within pixel cell area in ESA CCI 2019 northern hemisphere permafrost dataset (Type is String) coordinates: delta_time latitude longitude (Type is String) cloud_flag_atm[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: cloud flag atm (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 10 (Type is Int8) contentType: qualityInformation (Type is String) description: Cloud confidence flag from ATL09 that indicates the number of cloud or aerosol layers identified in each 25Hz atmospheric profile. If the flag is greater than 0, aerosols or clouds could be present. Valid range is 0 - 10. (Type is String) coordinates: delta_time latitude longitude (Type is String) snr[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: signal to noise ratio (Type is String) units: 1 (Type is String) source: ATBD Noise filtering via DRAGANN (Type is String) contentType: modelResult (Type is String) description: The signal to noise ratio of geolocated photons as determined by the ratio of the superset of ATL03 signal and DRAGANN found signal photons used for processing the ATL08 segments to the background photons (i.e. noise) within the same ATL08 segments. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_across[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas y (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Total cross-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_across. Sigma_atlas_y is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) layer_flag[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int8) attributes long_name: consolidated cloud flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: modelResult (Type is String) description: This flag is a combination of multiple flags (cloud_flag_atm, cloud_flag_asr, and bsnow_con) and takes daytime/nighttime into consideration. A value of 1 means clouds or blowing snow are likely present. A value of 0 indicates the likely absence of clouds or blowing snow. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: likely_clear likely_cloudy (Type is String) flag_values: 0, 1 (Type is Int8) segment_snowcover[ /gt1r/land_segments/delta_time= 0..19082] (Type is Byte) attributes long_name: segment snowcover (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_snowcover (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Daily snow/ice cover from ATL09 at the 25 Hz rate(275m) indicating likely presence of snow and ice within each segment. 0=ice free water; 1=snow free land; 2=snow; 3=ice. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: ice_free_water snow_free_land snow ice Undetermined (Type is String) flag_values: 0, 1, 2, 3, 255 (Type is Byte) beam_azimuth[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: beam azimuth (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Azimuth(in radians) of the unit pointing vector for the reference photon in the local ENU frame in radians. The angle is measured from north and positive towards East. (Type is String) coordinates: delta_time latitude longitude (Type is String) solar_azimuth[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes long_name: solar azimuth (Type is String) units: degrees_east (Type is String) source: ATL03 ATBD (Type is String) contentType: referenceInformation (Type is String) description: The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot. (Type is String) coordinates: delta_time latitude longitude (Type is String) psf_flag[ /gt1r/land_segments/delta_time= 0..19082] (Type is Byte) attributes long_name: point spread function flag (Type is String) units: 1 (Type is String) source: Land/Veg ATBD Refine Ground Estimates (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: referenceInformation (Type is String) description: Flag is set to 1 if the point spread function (computed as sigma_atlas_land) has exceeded the threshold (1 m) (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) segment_watermask[ /gt1r/land_segments/delta_time= 0..19082] (Type is Byte) attributes long_name: segment watermask (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_watermask (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Water mask(i.e. flag) indicating inland water as referenced from the Global Raster Water Mask(ANC33) at 250 m spatial resolution. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_water water Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) delta_time_end[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float64) attributes long_name: delta time end (Type is String) units: seconds since 2018-01-01 (Type is String) source: Derived (gps_seconds-gps_sec_offset) (Type is String) contentType: referenceInformation (Type is String) description: Time of the last photon contained within the data segment, in seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: delta_time latitude longitude (Type is String) segment_id_end[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int32) attributes long_name: end geolocation segment bin (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Geolocation segment number of the last photon in the land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) longitude_20m[ /gt1r/land_segments/delta_time= 0..19082] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: longitude of 20m segments (Type is String) units: degree (Type is String) source: ATBD Geosegment longitude (Type is String) valid_min: -180. (Type is Float32) valid_max: 180. (Type is Float32) contentType: modelResult (Type is String) description: Center longitude of 20m geosegments within each 100m land segment. (Type is String) coordinates: latitude longitude delta_time (Type is String) surf_type[ /gt1r/land_segments/delta_time= 0..19082] [ /ds_surf_type= 0..4] (Type is Int8) attributes long_name: surface type (Type is String) units: 1 (Type is String) source: ATL03 ATBD (Type is String) valid_min: 0 (Type is Int8) valid_max: 1 (Type is Int8) contentType: referenceInformation (Type is String) description: Flags describing which surface types this interval is associated with. 0=not type, 1=is type. Order of array is land, ocean, sea ice, land ice, inland water. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_type is_type (Type is String) flag_values: 0, 1 (Type is Int8) brightness_flag[ /gt1r/land_segments/delta_time= 0..19082] (Type is Byte) attributes long_name: brightness flag (Type is String) units: 1 (Type is String) source: Land ATBD Brightness_flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: Flag indicating that the ground surface is bright (e.g. snow-covered or other bright surfaces) (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_bright_surface bright_surface Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) segment_landcover[ /gt1r/land_segments/delta_time= 0..19082] (Type is Byte) attributes long_name: segment landcover (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_landcover (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: UN-FAO Land Cover Surface type classification as reference from Copernicus Land Cover(ANC18) at the 100m resolution. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: No_data Closed_forest_evergreen_needle_leaf Closed_forest_deciduous_needle_leaf Closed_forest_evergreen_broad_leaf Closed_forest_deciduous_broad_leaf Closed_forest_mixed Closed_forest_unknown Open_forest_evergreen_needle_leaf Open_forest_deciduous_needle_leaf Open_forest_evergreen_broad_leaf Open_forest_deciduous_broad_leaf Open_forest_mixed Open_forest_unknown Shrubs Herbaceous Herbaceous_wetleand Moss_and_lichen Bare_sparse_vegetation Cultivated_and_managed_vegetation_agriculture Urban_built_up Snow_and_ice Permanent_water_bodies Open_sea Undetermined (Type is String) flag_values: 0, 111, 113, 112, 114, 115, 116, 121, 123, 122, 124, 125, 126, 20, 30, 90, 100, 60, 40, 50, 70, 80, 200, 255 (Type is Byte) ph_removal_flag[ /gt1r/land_segments/delta_time= 0..19082] (Type is Byte) attributes long_name: ph removal flag (Type is String) units: 1 (Type is String) source: ATBD Final photon classification QA (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Flag indicating more than ph_removal_percent_limit (default 50.0) removed from land segment due to failing QA tests (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) asr[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: apparent surface reflectance (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: auxiliaryInformation (Type is String) description: Apparent surface reflectance (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_atlas_land[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas land (Type is String) units: 1 (Type is String) source: Land ATBD Refine Ground Estimates (Type is String) contentType: referenceInformation (Type is String) description: Total vertical geolocation error due to ranging and local surface slope. The parameter is computed for ATL08 as described in equation 1.2 ATL08 ATBD. (Type is String) coordinates: delta_time latitude longitude (Type is String) segment_id_beg[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int32) attributes long_name: begin geolocation segment bin (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Geolocation segment number of the first photon in the land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_along[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas x (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Total along-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_along. Sigma_atlas_x is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_h[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: dem height (Type is String) units: meters (Type is String) source: Arctic, Antarctic, Global, MSS DEM (Type is String) contentType: referenceInformation (Type is String) description: Best available DEM (in priority of Arctic/Antarctic/Global/MSS) value at the geolocation point. Height is in meters above the WGS84 Ellipsoid. (Type is String) coordinates: delta_time latitude longitude (Type is String) beam_coelev[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: beam co-elevation (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Co-elevation (CE) is direction from vertical of the laser beam as seen by an observer located at the laser ground spot. (Type is String) coordinates: delta_time latitude longitude (Type is String) sat_flag[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int8) attributes long_name: saturation flag (Type is String) units: 1 (Type is String) source: ATL03, Land ATBD Saturation Flag (Type is String) valid_min: -1 (Type is Int8) valid_max: 127 (Type is Int8) contentType: auxiliaryInformation (Type is String) description: Flag derived from full_sat_fract on the ATL03 data product, averaged over 5 geosegments in 100m land segment (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_saturation_detected saturation_detected not_enough_valid_data Undetermined (Type is String) flag_values: 0, 1, -1, 127 (Type is Int8) sigma_topo[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas topo (Type is String) units: 1 (Type is String) source: Land ATBD Refine Ground Estimates (Type is String) contentType: referenceInformation (Type is String) description: Total uncertainty that include sigma_h plus geolocation uncertainty due to local slope (equation 1.3). The local slope is multiplied by the geolocation uncertainty factor. This will be used to determine the total vertical geolocation error due to ranging and local slope. (Type is String) coordinates: delta_time latitude longitude (Type is String) night_flag[ /gt1r/land_segments/delta_time= 0..19082] (Type is Byte) attributes long_name: night flag (Type is String) units: 1 (Type is String) source: Land ATBD Night_Flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Flag indicating the data were acquired in night conditions: 0=day, 1=night. Flag is derived from solar elevation at the geolocated segment. IF solar elevation is above threshold it is day, if not then it is night. Threshold is set in atlas_l3a_const_mod. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: day night Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) delta_time_beg[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float64) attributes long_name: delta time begin (Type is String) units: seconds since 2018-01-01 (Type is String) source: Derived (gps_seconds-gps_sec_offset) (Type is String) contentType: referenceInformation (Type is String) description: Time of the first photon contained within the data segment, in seconds since the ATLAS SDP GPS Epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_h[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: height uncertainty (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m) provided at the geolocation segment rate on ATL03. Sigma_h is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) last_seg_extend[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes long_name: last segment extended (Type is String) standard_name: last_seg_extend (Type is String) units: kilometers (Type is String) source: Land ATBD Preparing ATL03 data for input (Type is String) contentType: auxiliaryInformation (Type is String) description: The distance (km) that the last ATL08 processing segment in a file is either extended or overlapped with the previous ATL08 processing segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) column_od_asr[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Column optical depth from ASR (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: auxiliaryInformation (Type is String) description: Optical depth of atmosphere column based on apparent surface reflectance and the assumed actual surface reflectance. (Type is String) coordinates: delta_time latitude longitude (Type is String) atlas_pa[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: atlas pointing angle (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Off nadir pointing angle (in radians) of the satellite to increase spatial sampling in the non-polar regions. ATLAS_PA =radians(90degs-beam_coelev). (Type is String) coordinates: delta_time latitude longitude (Type is String) ph_ndx_beg[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int64) attributes long_name: photon index begin (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Index (1-based) within the photon-rate data (/land_segments/photons) of the first photon within this each land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) solar_elevation[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes long_name: solar elevation (Type is String) units: degrees (Type is String) source: ATL03 ATBD (Type is String) contentType: referenceInformation (Type is String) description: Solar Angle above or below the plane tangent to the ellipsoid surface at the laser spot. Positive values mean the sun is above the horizon, while negative values mean it is below the horizon. The effect of atmospheric refraction is not included. This is a low precision value, with approximately TBD degree accuracy. (Type is String) coordinates: delta_time latitude longitude (Type is String) latitude_20m[ /gt1r/land_segments/delta_time= 0..19082] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: latitude of 20m segments (Type is String) units: degree (Type is String) source: ATBD Geosegment latitude (Type is String) valid_min: -90. (Type is Float32) valid_max: 90. (Type is Float32) contentType: modelResult (Type is String) description: Center latitude of 20m geosegments within each 100m land segment. (Type is String) coordinates: latitude longitude delta_time (Type is String) cloud_fold_flag[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int8) attributes long_name: cloud folding flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: modelResult (Type is String) description: Flag that indicates this profile likely contains cloud signal folded down from above 15 km to the last 2-3 km of the profile. See ATL09 ATBD Table 3.9 for detailed flag value meanings. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_folding goes5_indicates profile_indicates both_indicate outside_limits (Type is String) flag_values: 0, 1, 2, 3, 127 (Type is Int8) n_seg_ph[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int32) attributes long_name: number of photons (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of photons within each land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) terrain_flg[ /gt1r/land_segments/delta_time= 0..19082] (Type is Byte) attributes long_name: terrain flag (Type is String) units: 1 (Type is String) source: Land ATBD Segment_terrain flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Terrain flag quality check to indicate a deviation above a threshold from the reference DEM height reported on the product. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) urban_flag[ /gt1r/land_segments/delta_time= 0..19082] (Type is Byte) attributes long_name: segment urban flag (Type is String) units: 1 (Type is String) source: Land ATBD Urban_flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: The urban flag indicates that a segment is likely located over an urban area as determined by coincident pixels in the Global Urban Footprint (GUF) 0.4 arcsecond product. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_urban urban Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) permafrost_alt[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: permafrost active layer thickness (Type is String) standard_name: permafrost_alt (Type is String) units: meters (Type is String) source: ESA CCI, ANC47 (Type is String) valid_min: 0. (Type is Float32) valid_max: 100. (Type is Float32) contentType: referenceInformation (Type is String) description: Permafrost active layer thickness (m) from ESA CCI 2019 northern hemisphere permafrost dataset (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_removal_flag[ /gt1r/land_segments/delta_time= 0..19082] (Type is Byte) attributes long_name: dem removal flag (Type is String) units: 1 (Type is String) source: ATBD Segment reference DEM removal flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: Flag indicating more than dem_removal_percent_limit (default 20.0) removed from land segment due to failing DEM-QA tests (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) h_dif_ref[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: h dif from reference (Type is String) units: meters (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) contentType: modelResult (Type is String) description: Difference between h_te_median and ref_DEM (Type is String) coordinates: delta_time latitude longitude (Type is String) canopy(Type is Group) attributes description: Contains height parameters based on the land algorithm. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) h_canopy[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: height canopy (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: 98% height of all the individual canopy relative heights for the segment above the estimated terrain surface. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) canopy_rh_conf[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int8) attributes units: 1 (Type is String) long_name: canopy relative height confidence (Type is String) source: Land/Veg ATBD Vegetation Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 2 (Type is Int8) contentType: modelResult (Type is String) description: Canopy relative height confidence flag based on percentage of ground and canopy photons within a segment: 0 (<5% canopy), 1 (>5% canopy, <5% ground), 2 (>5% canopy, >5% ground). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: <5%_canopy >=5%_canopy_<5%_ground >=5%_canopy_>=5%_ground (Type is String) flag_values: 0, 1, 2 (Type is Int8) h_median_canopy_abs[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute segment median canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The median of individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_min_canopy[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: minimum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of relative individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_mean_canopy_abs[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute mean canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Mean of the individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_median_canopy[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: median canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The median of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. This parameter should be equivalent to RH50 reported in the literature. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_abs[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute segment canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The 98% height of all the absolute individual canopy heights referenced above the WGS84 ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) toc_roughness[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: top of canopy roughness (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Standard deviation of the relative heights of all photons classified as top of canopy within the segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_min_canopy_abs[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute minimum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of absolute individual canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_dif_canopy[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy diff to median height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Difference between h_canopy and h_median_canopy (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_quad[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy quadratic mean (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The quadratic mean height of individual classified relative canopy photon heights above the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_20m[ /gt1r/land_segments/delta_time= 0..19082] [ /ds_geosegments= 0..4] (Type is Float32) attributes units: m (Type is String) _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy height 20m (Type is String) source: ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Canopy height for each 20m geosegment with each 100m land segment. (Type is String) coordinates: ../latitude ../longitude ../delta_time (Type is String) n_ca_photons[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int32) attributes long_name: number canopy photons (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The number of photons classified as canopy within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_can[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Canopy photon rate (Type is String) units: s^-1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Calculated photon rate of canopy photons within each 100m segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) centroid_height[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: centroid height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Optical centroid of all photons classified as either canopy or ground points within the segment. The heights used in this calculation are absolute heights above the reference ellipsoid. This parameter is equivalent to the centroid height produced ICESat GLA14. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) canopy_h_metrics_abs[ /gt1r/land_segments/delta_time= 0..19082] [ /ds_metrics= 0..17] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy absolute height metrics (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Height metrics based on the cumulative distribution of absolute canopy heights above the WGS84 Ellipsoid. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) can_noise[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy noise rate (Type is String) units: count/meter (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Number of noise photons calculated that fall within the canopy height for each 100 m segment based on ATL03 background rate parameters. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_mean_canopy[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mean canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Mean of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) subset_can_flag[ /gt1r/land_segments/delta_time= 0..19082] [ /ds_geosegments= 0..4] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: subset canopy flag (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: -1 (Type is Int8) valid_max: 1 (Type is Int8) contentType: modelResult (Type is String) description: Quality flag indicating the canopy photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: no_photon_data_within_geosegment no_canopy_photons_within_geosegment canopy_photons_present_within_geosegment (Type is String) flag_values: -1, 0, 1 (Type is Int8) canopy_h_metrics[ /gt1r/land_segments/delta_time= 0..19082] [ /ds_metrics= 0..17] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy height metrics (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Height metrics based on the cumulative distribution of relative canopy heights above the interpolated ground surface. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) n_toc_photons[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int32) attributes long_name: number top of canopy photons (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The number of photons classified as top of canopy within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_max_canopy_abs[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute maximum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Maximum of individual absolute canopy heights within segment referenced above the WGS84 ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_uncertainty[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment canopy height uncertainty (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: qualityInformation (Type is String) description: Uncertainty of the relative canopy heights for the segment. Incorporates all systematic uncertainties as well as uncertainty from errors of identified photons. See section 1 and equations 1.4 and 1.5 of the ATL08 ATBD. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_can_nr[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: noise reduced number of canopy photons (Type is String) units: s^-1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Noise removed photon canopy rate within each 100 m segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) can_quality_score[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int8) attributes units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: modelResult (Type is String) description: Canopy quality score based on coincident conditions, from ATL08 ATBD section titled "Canopy Quality Score". (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) _FillValue: 127 (Type is Int8) long_name: canopy quality score (Type is String) canopy_openness[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy openness (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Standard Deviation of all photons classified as canopy photons within the segment to provide inference of canopy openness. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_max_canopy[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: maximum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Relative maximum of individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. Should be equivalent to RH100 metric reported in the literature. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) segment_cover[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int16) attributes _FillValue: 32767 (Type is Int16) long_name: canopy cover percentage (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Average percentage value of the valid (value <= 100) Copernicus fractional cover product for each 100 m segment. This data is temporally static, and is the summation of forest and shrub land cover fractions. Source data from: https://land.copernicus.eu/en/products/global-dynamic-land-cover/copernicus-global-land-service-land-cover-100m-collection-3-epoch-2019-globe . (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) terrain(Type is Group) attributes description: Contains terrain parameters at a 100m aggregation. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) h_te_uncertainty[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: uncertainty of h_te_mean (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Uncertainty of the mean terrain height for the segment. This uncertainty incorporates all systematic uncertainties(e.g. timing orbits, geolocation,etc.) as well as uncertainty from errors of identified photons. This parameter is described in section 1, equation 1.4 in ATL08 ATBD. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_mean[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mean terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The mean of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_min[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: minimum terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_te[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Terrain photon rate (Type is String) units: s^-1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Calculated photon rate of terrain photons within each 100m segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_interp[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: interpolated terrain surface height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Interpolated terrain surface height above the WGS84 Ellipsoid at the midpoint of the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_max[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: maximum terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The maximum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_rh25[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes units: meters (Type is String) _FillValue: 3.402823466e+38 (Type is Float32) long_name: Terrain height 25% percentile (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The terrain elevation from the 25% height. The classified ground photons are sorted into a cumulative distribution and the height associated with the 25% height for that segment is reported. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_skew[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: skew of terrain heights (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The skewness of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_best_fit_20m[ /gt1r/land_segments/delta_time= 0..19082] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: best fit 20m (Type is String) units: m (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Best fit terrain height to center of each 20m geosegment within each 100m land segment. (Type is String) coordinates: ../latitude ../longitude ../delta_time (Type is String) h_te_median[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: median terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The median of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_best_fit[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain height best fit (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The best fit terrain elevation at the the mid-point location of each 100m segment. The mid-segment terrain elevation is determined by selecting the best of three fits- linear, 3rd order and 4th order polynomials - to the terrain photons and interpolating the elevation at the mid-point location of the 100 m segment. For the linear fit, a slope correction and weighting is applied to each ground photon based on the distance to the slope height at the center of the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_std[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain roughness (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The standard deviation of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) terrain_slope[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain slope (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The along-track slope of terrain, within each segment;computed by a linear fit of terrain classified photons. Slope is in units of delta height over delta along track distance. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) subset_te_flag[ /gt1r/land_segments/delta_time= 0..19082] [ /ds_geosegments= 0..4] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: subset terrain flag (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: -1 (Type is Int8) valid_max: 1 (Type is Int8) contentType: modelResult (Type is String) description: Quality flag indicating the terrain photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: no_photon_data_within_geosegment no_terrain_photons_within_geosegment terrain_photons_present_within_geosegment (Type is String) flag_values: -1, 0, 1 (Type is Int8) n_te_photons[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int32) attributes long_name: number of ground photons (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The number of the photons classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_mode[ /gt1r/land_segments/delta_time= 0..19082] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mode of terrain heights (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The mode of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) te_quality_score[ /gt1r/land_segments/delta_time= 0..19082] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: terrain quality score (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: modelResult (Type is String) description: Quality score based on coincident conditions, from ATL08 ATBD section titled "Terrain Quality Score". (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) signal_photons(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) description: Contains parameters related to individual photons. (Type is String) data_rate: Data are stored at the signal-photon classification rate. (Type is String) Dimensions: [ /gt1r/signal_photons/delta_time = 0..1634892 ] delta_time[ /gt1r/signal_photons/delta_time= 0..1634892] (Type is Float64) attributes long_name: delta time (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: ATL03 (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) classed_pc_indx[ /gt1r/signal_photons/delta_time= 0..1634892] (Type is Int32) attributes units: 1 (Type is String) long_name: indicies of classed photons (Type is String) source: Retained from prior a_alt_science_ph packet (Type is String) contentType: referenceInformation (Type is String) description: Index (1-based) of the ATL08 classified signal photon from the start of the ATL03 geolocation segment specified on the ATL08 product at the photon rate in the corresponding parameter, ph_segment_id. This index traces back to specific photon within a 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group. (Type is String) coordinates: delta_time (Type is String) ph_h[ /gt1r/signal_photons/delta_time= 0..1634892] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: relative photon height (Type is String) standard_name: height (Type is String) units: meters (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: physicalMeasurement (Type is String) description: Height of photons above interpolated land surface (Type is String) coordinates: delta_time (Type is String) d_flag[ /gt1r/signal_photons/delta_time= 0..1634892] (Type is Int8) attributes long_name: dragann flag (Type is String) units: 1 (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: qualityInformation (Type is String) description: Flag indicating the labeling of DRAGANN noise filtering for a given photon. (Type is String) coordinates: delta_time (Type is String) flag_meanings: noise signal (Type is String) flag_values: 0, 1 (Type is Int8) classed_pc_flag[ /gt1r/signal_photons/delta_time= 0..1634892] (Type is Int8) attributes long_name: photon land atbd classification (Type is String) units: 1 (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: modelResult (Type is String) description: Land Vegetation ATBD classification flag for each photon as either noise, ground, canopy, and top of canopy. 0 = noise, 1 = ground, 2 = canopy, or 3 = top of canopy. (Type is String) coordinates: delta_time (Type is String) flag_meanings: noise ground canopy top_of_canopy (Type is String) flag_values: 0, 1, 2, 3 (Type is Int8) ph_segment_id[ /gt1r/signal_photons/delta_time= 0..1634892] (Type is Int32) attributes long_name: segment id of photon (Type is String) units: 1 (Type is String) source: Retained from prior a_alt_science_ph packet (Type is String) contentType: referenceInformation (Type is String) description: Segment ID of photons tracing back to specific 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the photon on ATL03 is the segment_id, orbit, and classed_pc_indx. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group. (Type is String) coordinates: delta_time (Type is String) gt2r(Type is Group) attributes atlas_pce: pce2 (Type is String) atlas_beam_type: weak (Type is String) groundtrack_id: gt2r (Type is String) atmosphere_profile: profile_2 (Type is String) atlas_spot_number: 4 (Type is String) sc_orientation: Backward (Type is String) land_segments(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) description: Contains data categorized as land at 100 meter intervals. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) Dimensions: [ /gt2r/land_segments/delta_time = 0..18455 ] longitude[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes long_name: longitude (Type is String) standard_name: longitude (Type is String) units: degrees (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) valid_min: -180. (Type is Float32) valid_max: 180. (Type is Float32) contentType: modelResult (Type is String) description: Longitude of the center-most signal photon within each segment. (Type is String) coordinates: delta_time latitude (Type is String) latitude[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes long_name: latitude (Type is String) standard_name: latitude (Type is String) units: degrees (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) valid_min: -90. (Type is Float32) valid_max: 90. (Type is Float32) contentType: modelResult (Type is String) description: Latitude of the center-most signal photon within each segment. (Type is String) coordinates: delta_time longitude (Type is String) delta_time[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float64) attributes long_name: mean_pass_time (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) contentType: referenceInformation (Type is String) description: Mean time for the segment in number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: latitude longitude (Type is String) rgt[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int16) attributes long_name: reference ground track (Type is String) units: 1 (Type is String) source: Operations (Type is String) valid_min: 1 (Type is Int16) valid_max: 1387 (Type is Int16) contentType: referenceInformation (Type is String) description: The reference ground track (RGT) is the track on the earth at which a specified unit vector within the observatory is pointed. Under nominal operating conditions, there will be no data collected along the RGT, as the RGT is spanned by GT3 and GT4. During slews or off-pointing, it is possible that ground tracks may intersect the RGT. The ICESat-2 mission has 1387 RGTs. (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_flag[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int8) attributes long_name: dem source flag (Type is String) units: 1 (Type is String) source: Atmosphere ATBD (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: referenceInformation (Type is String) description: Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=Global, 3=MSS, 4=Antarctic. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: none arctic global mss antarctic Undetermined (Type is String) flag_values: 0, 1, 2, 3, 4, 127 (Type is Int8) msw_flag[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int8) attributes long_name: multiple scattering warning flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: qualityInformation (Type is String) description: Multiple Scattering Warning flag. If no layers were detected, then msw_flag = 0. If blowing snow is detected and its estimated optical depth is greater than or equal to 0.5, then msw_flag = 5. If the blowing snow optical depth is less than 0.5, then msw_flag = 4. If no blowing snow is detected but there are cloud or aerosol layers detected, the msw_flag assumes values of 1 to 3 based on the height of the bottom of the lowest layer: < 1 km, msw_flag = 3; 1-3 km, msw_flag = 2; > 3km, msw_flag = 1. A value of 127 indicates that the signal to noise of the data was too low to reliably ascertain the presence of cloud or blowing snow. We expect values of 127 to occur only during daylight. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: cannot_determine no_layers layer_gt_3km layer_between_1_and_3_km layer_lt_1km blow_snow_od_lt_0.5 blow_snow_od_gt_0.5 (Type is String) flag_values: 127, 0, 1, 2, 3, 4, 5 (Type is Int8) permafrost_prob[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: permafrost probaility (Type is String) standard_name: permafrost_prob (Type is String) units: percent (Type is String) source: ESA CCI, ANC47 (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: referenceInformation (Type is String) description: Permafrost probability (0 - 100) derived via percent of permafrost within pixel cell area in ESA CCI 2019 northern hemisphere permafrost dataset (Type is String) coordinates: delta_time latitude longitude (Type is String) cloud_flag_atm[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: cloud flag atm (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 10 (Type is Int8) contentType: qualityInformation (Type is String) description: Cloud confidence flag from ATL09 that indicates the number of cloud or aerosol layers identified in each 25Hz atmospheric profile. If the flag is greater than 0, aerosols or clouds could be present. Valid range is 0 - 10. (Type is String) coordinates: delta_time latitude longitude (Type is String) snr[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: signal to noise ratio (Type is String) units: 1 (Type is String) source: ATBD Noise filtering via DRAGANN (Type is String) contentType: modelResult (Type is String) description: The signal to noise ratio of geolocated photons as determined by the ratio of the superset of ATL03 signal and DRAGANN found signal photons used for processing the ATL08 segments to the background photons (i.e. noise) within the same ATL08 segments. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_across[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas y (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Total cross-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_across. Sigma_atlas_y is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) layer_flag[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int8) attributes long_name: consolidated cloud flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: modelResult (Type is String) description: This flag is a combination of multiple flags (cloud_flag_atm, cloud_flag_asr, and bsnow_con) and takes daytime/nighttime into consideration. A value of 1 means clouds or blowing snow are likely present. A value of 0 indicates the likely absence of clouds or blowing snow. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: likely_clear likely_cloudy (Type is String) flag_values: 0, 1 (Type is Int8) segment_snowcover[ /gt2r/land_segments/delta_time= 0..18455] (Type is Byte) attributes long_name: segment snowcover (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_snowcover (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Daily snow/ice cover from ATL09 at the 25 Hz rate(275m) indicating likely presence of snow and ice within each segment. 0=ice free water; 1=snow free land; 2=snow; 3=ice. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: ice_free_water snow_free_land snow ice Undetermined (Type is String) flag_values: 0, 1, 2, 3, 255 (Type is Byte) beam_azimuth[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: beam azimuth (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Azimuth(in radians) of the unit pointing vector for the reference photon in the local ENU frame in radians. The angle is measured from north and positive towards East. (Type is String) coordinates: delta_time latitude longitude (Type is String) solar_azimuth[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes long_name: solar azimuth (Type is String) units: degrees_east (Type is String) source: ATL03 ATBD (Type is String) contentType: referenceInformation (Type is String) description: The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot. (Type is String) coordinates: delta_time latitude longitude (Type is String) psf_flag[ /gt2r/land_segments/delta_time= 0..18455] (Type is Byte) attributes long_name: point spread function flag (Type is String) units: 1 (Type is String) source: Land/Veg ATBD Refine Ground Estimates (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: referenceInformation (Type is String) description: Flag is set to 1 if the point spread function (computed as sigma_atlas_land) has exceeded the threshold (1 m) (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) segment_watermask[ /gt2r/land_segments/delta_time= 0..18455] (Type is Byte) attributes long_name: segment watermask (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_watermask (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Water mask(i.e. flag) indicating inland water as referenced from the Global Raster Water Mask(ANC33) at 250 m spatial resolution. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_water water Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) delta_time_end[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float64) attributes long_name: delta time end (Type is String) units: seconds since 2018-01-01 (Type is String) source: Derived (gps_seconds-gps_sec_offset) (Type is String) contentType: referenceInformation (Type is String) description: Time of the last photon contained within the data segment, in seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: delta_time latitude longitude (Type is String) segment_id_end[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int32) attributes long_name: end geolocation segment bin (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Geolocation segment number of the last photon in the land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) longitude_20m[ /gt2r/land_segments/delta_time= 0..18455] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: longitude of 20m segments (Type is String) units: degree (Type is String) source: ATBD Geosegment longitude (Type is String) valid_min: -180. (Type is Float32) valid_max: 180. (Type is Float32) contentType: modelResult (Type is String) description: Center longitude of 20m geosegments within each 100m land segment. (Type is String) coordinates: latitude longitude delta_time (Type is String) surf_type[ /gt2r/land_segments/delta_time= 0..18455] [ /ds_surf_type= 0..4] (Type is Int8) attributes long_name: surface type (Type is String) units: 1 (Type is String) source: ATL03 ATBD (Type is String) valid_min: 0 (Type is Int8) valid_max: 1 (Type is Int8) contentType: referenceInformation (Type is String) description: Flags describing which surface types this interval is associated with. 0=not type, 1=is type. Order of array is land, ocean, sea ice, land ice, inland water. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_type is_type (Type is String) flag_values: 0, 1 (Type is Int8) brightness_flag[ /gt2r/land_segments/delta_time= 0..18455] (Type is Byte) attributes long_name: brightness flag (Type is String) units: 1 (Type is String) source: Land ATBD Brightness_flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: Flag indicating that the ground surface is bright (e.g. snow-covered or other bright surfaces) (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_bright_surface bright_surface Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) segment_landcover[ /gt2r/land_segments/delta_time= 0..18455] (Type is Byte) attributes long_name: segment landcover (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_landcover (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: UN-FAO Land Cover Surface type classification as reference from Copernicus Land Cover(ANC18) at the 100m resolution. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: No_data Closed_forest_evergreen_needle_leaf Closed_forest_deciduous_needle_leaf Closed_forest_evergreen_broad_leaf Closed_forest_deciduous_broad_leaf Closed_forest_mixed Closed_forest_unknown Open_forest_evergreen_needle_leaf Open_forest_deciduous_needle_leaf Open_forest_evergreen_broad_leaf Open_forest_deciduous_broad_leaf Open_forest_mixed Open_forest_unknown Shrubs Herbaceous Herbaceous_wetleand Moss_and_lichen Bare_sparse_vegetation Cultivated_and_managed_vegetation_agriculture Urban_built_up Snow_and_ice Permanent_water_bodies Open_sea Undetermined (Type is String) flag_values: 0, 111, 113, 112, 114, 115, 116, 121, 123, 122, 124, 125, 126, 20, 30, 90, 100, 60, 40, 50, 70, 80, 200, 255 (Type is Byte) ph_removal_flag[ /gt2r/land_segments/delta_time= 0..18455] (Type is Byte) attributes long_name: ph removal flag (Type is String) units: 1 (Type is String) source: ATBD Final photon classification QA (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Flag indicating more than ph_removal_percent_limit (default 50.0) removed from land segment due to failing QA tests (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) asr[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: apparent surface reflectance (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: auxiliaryInformation (Type is String) description: Apparent surface reflectance (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_atlas_land[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas land (Type is String) units: 1 (Type is String) source: Land ATBD Refine Ground Estimates (Type is String) contentType: referenceInformation (Type is String) description: Total vertical geolocation error due to ranging and local surface slope. The parameter is computed for ATL08 as described in equation 1.2 ATL08 ATBD. (Type is String) coordinates: delta_time latitude longitude (Type is String) segment_id_beg[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int32) attributes long_name: begin geolocation segment bin (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Geolocation segment number of the first photon in the land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_along[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas x (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Total along-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_along. Sigma_atlas_x is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_h[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: dem height (Type is String) units: meters (Type is String) source: Arctic, Antarctic, Global, MSS DEM (Type is String) contentType: referenceInformation (Type is String) description: Best available DEM (in priority of Arctic/Antarctic/Global/MSS) value at the geolocation point. Height is in meters above the WGS84 Ellipsoid. (Type is String) coordinates: delta_time latitude longitude (Type is String) beam_coelev[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: beam co-elevation (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Co-elevation (CE) is direction from vertical of the laser beam as seen by an observer located at the laser ground spot. (Type is String) coordinates: delta_time latitude longitude (Type is String) sat_flag[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int8) attributes long_name: saturation flag (Type is String) units: 1 (Type is String) source: ATL03, Land ATBD Saturation Flag (Type is String) valid_min: -1 (Type is Int8) valid_max: 127 (Type is Int8) contentType: auxiliaryInformation (Type is String) description: Flag derived from full_sat_fract on the ATL03 data product, averaged over 5 geosegments in 100m land segment (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_saturation_detected saturation_detected not_enough_valid_data Undetermined (Type is String) flag_values: 0, 1, -1, 127 (Type is Int8) sigma_topo[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas topo (Type is String) units: 1 (Type is String) source: Land ATBD Refine Ground Estimates (Type is String) contentType: referenceInformation (Type is String) description: Total uncertainty that include sigma_h plus geolocation uncertainty due to local slope (equation 1.3). The local slope is multiplied by the geolocation uncertainty factor. This will be used to determine the total vertical geolocation error due to ranging and local slope. (Type is String) coordinates: delta_time latitude longitude (Type is String) night_flag[ /gt2r/land_segments/delta_time= 0..18455] (Type is Byte) attributes long_name: night flag (Type is String) units: 1 (Type is String) source: Land ATBD Night_Flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Flag indicating the data were acquired in night conditions: 0=day, 1=night. Flag is derived from solar elevation at the geolocated segment. IF solar elevation is above threshold it is day, if not then it is night. Threshold is set in atlas_l3a_const_mod. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: day night Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) delta_time_beg[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float64) attributes long_name: delta time begin (Type is String) units: seconds since 2018-01-01 (Type is String) source: Derived (gps_seconds-gps_sec_offset) (Type is String) contentType: referenceInformation (Type is String) description: Time of the first photon contained within the data segment, in seconds since the ATLAS SDP GPS Epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_h[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: height uncertainty (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m) provided at the geolocation segment rate on ATL03. Sigma_h is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) last_seg_extend[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes long_name: last segment extended (Type is String) standard_name: last_seg_extend (Type is String) units: kilometers (Type is String) source: Land ATBD Preparing ATL03 data for input (Type is String) contentType: auxiliaryInformation (Type is String) description: The distance (km) that the last ATL08 processing segment in a file is either extended or overlapped with the previous ATL08 processing segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) column_od_asr[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Column optical depth from ASR (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: auxiliaryInformation (Type is String) description: Optical depth of atmosphere column based on apparent surface reflectance and the assumed actual surface reflectance. (Type is String) coordinates: delta_time latitude longitude (Type is String) atlas_pa[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: atlas pointing angle (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Off nadir pointing angle (in radians) of the satellite to increase spatial sampling in the non-polar regions. ATLAS_PA =radians(90degs-beam_coelev). (Type is String) coordinates: delta_time latitude longitude (Type is String) ph_ndx_beg[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int64) attributes long_name: photon index begin (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Index (1-based) within the photon-rate data (/land_segments/photons) of the first photon within this each land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) solar_elevation[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes long_name: solar elevation (Type is String) units: degrees (Type is String) source: ATL03 ATBD (Type is String) contentType: referenceInformation (Type is String) description: Solar Angle above or below the plane tangent to the ellipsoid surface at the laser spot. Positive values mean the sun is above the horizon, while negative values mean it is below the horizon. The effect of atmospheric refraction is not included. This is a low precision value, with approximately TBD degree accuracy. (Type is String) coordinates: delta_time latitude longitude (Type is String) latitude_20m[ /gt2r/land_segments/delta_time= 0..18455] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: latitude of 20m segments (Type is String) units: degree (Type is String) source: ATBD Geosegment latitude (Type is String) valid_min: -90. (Type is Float32) valid_max: 90. (Type is Float32) contentType: modelResult (Type is String) description: Center latitude of 20m geosegments within each 100m land segment. (Type is String) coordinates: latitude longitude delta_time (Type is String) cloud_fold_flag[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int8) attributes long_name: cloud folding flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: modelResult (Type is String) description: Flag that indicates this profile likely contains cloud signal folded down from above 15 km to the last 2-3 km of the profile. See ATL09 ATBD Table 3.9 for detailed flag value meanings. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_folding goes5_indicates profile_indicates both_indicate outside_limits (Type is String) flag_values: 0, 1, 2, 3, 127 (Type is Int8) n_seg_ph[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int32) attributes long_name: number of photons (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of photons within each land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) terrain_flg[ /gt2r/land_segments/delta_time= 0..18455] (Type is Byte) attributes long_name: terrain flag (Type is String) units: 1 (Type is String) source: Land ATBD Segment_terrain flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Terrain flag quality check to indicate a deviation above a threshold from the reference DEM height reported on the product. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) urban_flag[ /gt2r/land_segments/delta_time= 0..18455] (Type is Byte) attributes long_name: segment urban flag (Type is String) units: 1 (Type is String) source: Land ATBD Urban_flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: The urban flag indicates that a segment is likely located over an urban area as determined by coincident pixels in the Global Urban Footprint (GUF) 0.4 arcsecond product. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_urban urban Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) permafrost_alt[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: permafrost active layer thickness (Type is String) standard_name: permafrost_alt (Type is String) units: meters (Type is String) source: ESA CCI, ANC47 (Type is String) valid_min: 0. (Type is Float32) valid_max: 100. (Type is Float32) contentType: referenceInformation (Type is String) description: Permafrost active layer thickness (m) from ESA CCI 2019 northern hemisphere permafrost dataset (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_removal_flag[ /gt2r/land_segments/delta_time= 0..18455] (Type is Byte) attributes long_name: dem removal flag (Type is String) units: 1 (Type is String) source: ATBD Segment reference DEM removal flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: Flag indicating more than dem_removal_percent_limit (default 20.0) removed from land segment due to failing DEM-QA tests (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) h_dif_ref[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: h dif from reference (Type is String) units: meters (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) contentType: modelResult (Type is String) description: Difference between h_te_median and ref_DEM (Type is String) coordinates: delta_time latitude longitude (Type is String) canopy(Type is Group) attributes description: Contains height parameters based on the land algorithm. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) h_canopy[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: height canopy (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: 98% height of all the individual canopy relative heights for the segment above the estimated terrain surface. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) canopy_rh_conf[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int8) attributes units: 1 (Type is String) long_name: canopy relative height confidence (Type is String) source: Land/Veg ATBD Vegetation Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 2 (Type is Int8) contentType: modelResult (Type is String) description: Canopy relative height confidence flag based on percentage of ground and canopy photons within a segment: 0 (<5% canopy), 1 (>5% canopy, <5% ground), 2 (>5% canopy, >5% ground). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: <5%_canopy >=5%_canopy_<5%_ground >=5%_canopy_>=5%_ground (Type is String) flag_values: 0, 1, 2 (Type is Int8) h_median_canopy_abs[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute segment median canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The median of individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_min_canopy[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: minimum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of relative individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_mean_canopy_abs[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute mean canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Mean of the individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_median_canopy[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: median canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The median of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. This parameter should be equivalent to RH50 reported in the literature. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_abs[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute segment canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The 98% height of all the absolute individual canopy heights referenced above the WGS84 ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) toc_roughness[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: top of canopy roughness (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Standard deviation of the relative heights of all photons classified as top of canopy within the segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_min_canopy_abs[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute minimum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of absolute individual canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_dif_canopy[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy diff to median height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Difference between h_canopy and h_median_canopy (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_quad[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy quadratic mean (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The quadratic mean height of individual classified relative canopy photon heights above the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_20m[ /gt2r/land_segments/delta_time= 0..18455] [ /ds_geosegments= 0..4] (Type is Float32) attributes units: m (Type is String) _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy height 20m (Type is String) source: ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Canopy height for each 20m geosegment with each 100m land segment. (Type is String) coordinates: ../latitude ../longitude ../delta_time (Type is String) n_ca_photons[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int32) attributes long_name: number canopy photons (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The number of photons classified as canopy within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_can[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Canopy photon rate (Type is String) units: s^-1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Calculated photon rate of canopy photons within each 100m segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) centroid_height[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: centroid height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Optical centroid of all photons classified as either canopy or ground points within the segment. The heights used in this calculation are absolute heights above the reference ellipsoid. This parameter is equivalent to the centroid height produced ICESat GLA14. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) canopy_h_metrics_abs[ /gt2r/land_segments/delta_time= 0..18455] [ /ds_metrics= 0..17] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy absolute height metrics (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Height metrics based on the cumulative distribution of absolute canopy heights above the WGS84 Ellipsoid. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) can_noise[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy noise rate (Type is String) units: count/meter (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Number of noise photons calculated that fall within the canopy height for each 100 m segment based on ATL03 background rate parameters. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_mean_canopy[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mean canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Mean of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) subset_can_flag[ /gt2r/land_segments/delta_time= 0..18455] [ /ds_geosegments= 0..4] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: subset canopy flag (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: -1 (Type is Int8) valid_max: 1 (Type is Int8) contentType: modelResult (Type is String) description: Quality flag indicating the canopy photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: no_photon_data_within_geosegment no_canopy_photons_within_geosegment canopy_photons_present_within_geosegment (Type is String) flag_values: -1, 0, 1 (Type is Int8) canopy_h_metrics[ /gt2r/land_segments/delta_time= 0..18455] [ /ds_metrics= 0..17] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy height metrics (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Height metrics based on the cumulative distribution of relative canopy heights above the interpolated ground surface. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) n_toc_photons[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int32) attributes long_name: number top of canopy photons (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The number of photons classified as top of canopy within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_max_canopy_abs[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute maximum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Maximum of individual absolute canopy heights within segment referenced above the WGS84 ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_uncertainty[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment canopy height uncertainty (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: qualityInformation (Type is String) description: Uncertainty of the relative canopy heights for the segment. Incorporates all systematic uncertainties as well as uncertainty from errors of identified photons. See section 1 and equations 1.4 and 1.5 of the ATL08 ATBD. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_can_nr[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: noise reduced number of canopy photons (Type is String) units: s^-1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Noise removed photon canopy rate within each 100 m segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) can_quality_score[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int8) attributes units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: modelResult (Type is String) description: Canopy quality score based on coincident conditions, from ATL08 ATBD section titled "Canopy Quality Score". (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) _FillValue: 127 (Type is Int8) long_name: canopy quality score (Type is String) canopy_openness[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy openness (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Standard Deviation of all photons classified as canopy photons within the segment to provide inference of canopy openness. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_max_canopy[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: maximum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Relative maximum of individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. Should be equivalent to RH100 metric reported in the literature. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) segment_cover[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int16) attributes _FillValue: 32767 (Type is Int16) long_name: canopy cover percentage (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Average percentage value of the valid (value <= 100) Copernicus fractional cover product for each 100 m segment. This data is temporally static, and is the summation of forest and shrub land cover fractions. Source data from: https://land.copernicus.eu/en/products/global-dynamic-land-cover/copernicus-global-land-service-land-cover-100m-collection-3-epoch-2019-globe . (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) terrain(Type is Group) attributes description: Contains terrain parameters at a 100m aggregation. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) h_te_uncertainty[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: uncertainty of h_te_mean (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Uncertainty of the mean terrain height for the segment. This uncertainty incorporates all systematic uncertainties(e.g. timing orbits, geolocation,etc.) as well as uncertainty from errors of identified photons. This parameter is described in section 1, equation 1.4 in ATL08 ATBD. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_mean[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mean terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The mean of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_min[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: minimum terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_te[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Terrain photon rate (Type is String) units: s^-1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Calculated photon rate of terrain photons within each 100m segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_interp[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: interpolated terrain surface height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Interpolated terrain surface height above the WGS84 Ellipsoid at the midpoint of the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_max[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: maximum terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The maximum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_rh25[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes units: meters (Type is String) _FillValue: 3.402823466e+38 (Type is Float32) long_name: Terrain height 25% percentile (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The terrain elevation from the 25% height. The classified ground photons are sorted into a cumulative distribution and the height associated with the 25% height for that segment is reported. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_skew[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: skew of terrain heights (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The skewness of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_best_fit_20m[ /gt2r/land_segments/delta_time= 0..18455] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: best fit 20m (Type is String) units: m (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Best fit terrain height to center of each 20m geosegment within each 100m land segment. (Type is String) coordinates: ../latitude ../longitude ../delta_time (Type is String) h_te_median[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: median terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The median of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_best_fit[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain height best fit (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The best fit terrain elevation at the the mid-point location of each 100m segment. The mid-segment terrain elevation is determined by selecting the best of three fits- linear, 3rd order and 4th order polynomials - to the terrain photons and interpolating the elevation at the mid-point location of the 100 m segment. For the linear fit, a slope correction and weighting is applied to each ground photon based on the distance to the slope height at the center of the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_std[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain roughness (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The standard deviation of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) terrain_slope[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain slope (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The along-track slope of terrain, within each segment;computed by a linear fit of terrain classified photons. Slope is in units of delta height over delta along track distance. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) subset_te_flag[ /gt2r/land_segments/delta_time= 0..18455] [ /ds_geosegments= 0..4] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: subset terrain flag (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: -1 (Type is Int8) valid_max: 1 (Type is Int8) contentType: modelResult (Type is String) description: Quality flag indicating the terrain photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: no_photon_data_within_geosegment no_terrain_photons_within_geosegment terrain_photons_present_within_geosegment (Type is String) flag_values: -1, 0, 1 (Type is Int8) n_te_photons[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int32) attributes long_name: number of ground photons (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The number of the photons classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_mode[ /gt2r/land_segments/delta_time= 0..18455] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mode of terrain heights (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The mode of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) te_quality_score[ /gt2r/land_segments/delta_time= 0..18455] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: terrain quality score (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: modelResult (Type is String) description: Quality score based on coincident conditions, from ATL08 ATBD section titled "Terrain Quality Score". (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) signal_photons(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) description: Contains parameters related to individual photons. (Type is String) data_rate: Data are stored at the signal-photon classification rate. (Type is String) Dimensions: [ /gt2r/signal_photons/delta_time = 0..1470826 ] delta_time[ /gt2r/signal_photons/delta_time= 0..1470826] (Type is Float64) attributes long_name: delta time (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: ATL03 (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) classed_pc_indx[ /gt2r/signal_photons/delta_time= 0..1470826] (Type is Int32) attributes units: 1 (Type is String) long_name: indicies of classed photons (Type is String) source: Retained from prior a_alt_science_ph packet (Type is String) contentType: referenceInformation (Type is String) description: Index (1-based) of the ATL08 classified signal photon from the start of the ATL03 geolocation segment specified on the ATL08 product at the photon rate in the corresponding parameter, ph_segment_id. This index traces back to specific photon within a 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group. (Type is String) coordinates: delta_time (Type is String) ph_h[ /gt2r/signal_photons/delta_time= 0..1470826] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: relative photon height (Type is String) standard_name: height (Type is String) units: meters (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: physicalMeasurement (Type is String) description: Height of photons above interpolated land surface (Type is String) coordinates: delta_time (Type is String) d_flag[ /gt2r/signal_photons/delta_time= 0..1470826] (Type is Int8) attributes long_name: dragann flag (Type is String) units: 1 (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: qualityInformation (Type is String) description: Flag indicating the labeling of DRAGANN noise filtering for a given photon. (Type is String) coordinates: delta_time (Type is String) flag_meanings: noise signal (Type is String) flag_values: 0, 1 (Type is Int8) classed_pc_flag[ /gt2r/signal_photons/delta_time= 0..1470826] (Type is Int8) attributes long_name: photon land atbd classification (Type is String) units: 1 (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: modelResult (Type is String) description: Land Vegetation ATBD classification flag for each photon as either noise, ground, canopy, and top of canopy. 0 = noise, 1 = ground, 2 = canopy, or 3 = top of canopy. (Type is String) coordinates: delta_time (Type is String) flag_meanings: noise ground canopy top_of_canopy (Type is String) flag_values: 0, 1, 2, 3 (Type is Int8) ph_segment_id[ /gt2r/signal_photons/delta_time= 0..1470826] (Type is Int32) attributes long_name: segment id of photon (Type is String) units: 1 (Type is String) source: Retained from prior a_alt_science_ph packet (Type is String) contentType: referenceInformation (Type is String) description: Segment ID of photons tracing back to specific 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the photon on ATL03 is the segment_id, orbit, and classed_pc_indx. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group. (Type is String) coordinates: delta_time (Type is String) gt1l(Type is Group) attributes atlas_pce: pce1 (Type is String) atlas_beam_type: strong (Type is String) groundtrack_id: gt1l (Type is String) atmosphere_profile: profile_1 (Type is String) atlas_spot_number: 1 (Type is String) sc_orientation: Backward (Type is String) land_segments(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) description: Contains data categorized as land at 100 meter intervals. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) Dimensions: [ /gt1l/land_segments/delta_time = 0..23313 ] longitude[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes long_name: longitude (Type is String) standard_name: longitude (Type is String) units: degrees (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) valid_min: -180. (Type is Float32) valid_max: 180. (Type is Float32) contentType: modelResult (Type is String) description: Longitude of the center-most signal photon within each segment. (Type is String) coordinates: delta_time latitude (Type is String) latitude[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes long_name: latitude (Type is String) standard_name: latitude (Type is String) units: degrees (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) valid_min: -90. (Type is Float32) valid_max: 90. (Type is Float32) contentType: modelResult (Type is String) description: Latitude of the center-most signal photon within each segment. (Type is String) coordinates: delta_time longitude (Type is String) delta_time[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float64) attributes long_name: mean_pass_time (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) contentType: referenceInformation (Type is String) description: Mean time for the segment in number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: latitude longitude (Type is String) rgt[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int16) attributes long_name: reference ground track (Type is String) units: 1 (Type is String) source: Operations (Type is String) valid_min: 1 (Type is Int16) valid_max: 1387 (Type is Int16) contentType: referenceInformation (Type is String) description: The reference ground track (RGT) is the track on the earth at which a specified unit vector within the observatory is pointed. Under nominal operating conditions, there will be no data collected along the RGT, as the RGT is spanned by GT3 and GT4. During slews or off-pointing, it is possible that ground tracks may intersect the RGT. The ICESat-2 mission has 1387 RGTs. (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_flag[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int8) attributes long_name: dem source flag (Type is String) units: 1 (Type is String) source: Atmosphere ATBD (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: referenceInformation (Type is String) description: Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=Global, 3=MSS, 4=Antarctic. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: none arctic global mss antarctic Undetermined (Type is String) flag_values: 0, 1, 2, 3, 4, 127 (Type is Int8) msw_flag[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int8) attributes long_name: multiple scattering warning flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: qualityInformation (Type is String) description: Multiple Scattering Warning flag. If no layers were detected, then msw_flag = 0. If blowing snow is detected and its estimated optical depth is greater than or equal to 0.5, then msw_flag = 5. If the blowing snow optical depth is less than 0.5, then msw_flag = 4. If no blowing snow is detected but there are cloud or aerosol layers detected, the msw_flag assumes values of 1 to 3 based on the height of the bottom of the lowest layer: < 1 km, msw_flag = 3; 1-3 km, msw_flag = 2; > 3km, msw_flag = 1. A value of 127 indicates that the signal to noise of the data was too low to reliably ascertain the presence of cloud or blowing snow. We expect values of 127 to occur only during daylight. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: cannot_determine no_layers layer_gt_3km layer_between_1_and_3_km layer_lt_1km blow_snow_od_lt_0.5 blow_snow_od_gt_0.5 (Type is String) flag_values: 127, 0, 1, 2, 3, 4, 5 (Type is Int8) permafrost_prob[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: permafrost probaility (Type is String) standard_name: permafrost_prob (Type is String) units: percent (Type is String) source: ESA CCI, ANC47 (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: referenceInformation (Type is String) description: Permafrost probability (0 - 100) derived via percent of permafrost within pixel cell area in ESA CCI 2019 northern hemisphere permafrost dataset (Type is String) coordinates: delta_time latitude longitude (Type is String) cloud_flag_atm[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: cloud flag atm (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 10 (Type is Int8) contentType: qualityInformation (Type is String) description: Cloud confidence flag from ATL09 that indicates the number of cloud or aerosol layers identified in each 25Hz atmospheric profile. If the flag is greater than 0, aerosols or clouds could be present. Valid range is 0 - 10. (Type is String) coordinates: delta_time latitude longitude (Type is String) snr[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: signal to noise ratio (Type is String) units: 1 (Type is String) source: ATBD Noise filtering via DRAGANN (Type is String) contentType: modelResult (Type is String) description: The signal to noise ratio of geolocated photons as determined by the ratio of the superset of ATL03 signal and DRAGANN found signal photons used for processing the ATL08 segments to the background photons (i.e. noise) within the same ATL08 segments. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_across[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas y (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Total cross-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_across. Sigma_atlas_y is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) layer_flag[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int8) attributes long_name: consolidated cloud flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: modelResult (Type is String) description: This flag is a combination of multiple flags (cloud_flag_atm, cloud_flag_asr, and bsnow_con) and takes daytime/nighttime into consideration. A value of 1 means clouds or blowing snow are likely present. A value of 0 indicates the likely absence of clouds or blowing snow. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: likely_clear likely_cloudy (Type is String) flag_values: 0, 1 (Type is Int8) segment_snowcover[ /gt1l/land_segments/delta_time= 0..23313] (Type is Byte) attributes long_name: segment snowcover (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_snowcover (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Daily snow/ice cover from ATL09 at the 25 Hz rate(275m) indicating likely presence of snow and ice within each segment. 0=ice free water; 1=snow free land; 2=snow; 3=ice. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: ice_free_water snow_free_land snow ice Undetermined (Type is String) flag_values: 0, 1, 2, 3, 255 (Type is Byte) beam_azimuth[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: beam azimuth (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Azimuth(in radians) of the unit pointing vector for the reference photon in the local ENU frame in radians. The angle is measured from north and positive towards East. (Type is String) coordinates: delta_time latitude longitude (Type is String) solar_azimuth[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes long_name: solar azimuth (Type is String) units: degrees_east (Type is String) source: ATL03 ATBD (Type is String) contentType: referenceInformation (Type is String) description: The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot. (Type is String) coordinates: delta_time latitude longitude (Type is String) psf_flag[ /gt1l/land_segments/delta_time= 0..23313] (Type is Byte) attributes long_name: point spread function flag (Type is String) units: 1 (Type is String) source: Land/Veg ATBD Refine Ground Estimates (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: referenceInformation (Type is String) description: Flag is set to 1 if the point spread function (computed as sigma_atlas_land) has exceeded the threshold (1 m) (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) segment_watermask[ /gt1l/land_segments/delta_time= 0..23313] (Type is Byte) attributes long_name: segment watermask (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_watermask (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Water mask(i.e. flag) indicating inland water as referenced from the Global Raster Water Mask(ANC33) at 250 m spatial resolution. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_water water Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) delta_time_end[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float64) attributes long_name: delta time end (Type is String) units: seconds since 2018-01-01 (Type is String) source: Derived (gps_seconds-gps_sec_offset) (Type is String) contentType: referenceInformation (Type is String) description: Time of the last photon contained within the data segment, in seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: delta_time latitude longitude (Type is String) segment_id_end[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int32) attributes long_name: end geolocation segment bin (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Geolocation segment number of the last photon in the land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) longitude_20m[ /gt1l/land_segments/delta_time= 0..23313] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: longitude of 20m segments (Type is String) units: degree (Type is String) source: ATBD Geosegment longitude (Type is String) valid_min: -180. (Type is Float32) valid_max: 180. (Type is Float32) contentType: modelResult (Type is String) description: Center longitude of 20m geosegments within each 100m land segment. (Type is String) coordinates: latitude longitude delta_time (Type is String) surf_type[ /gt1l/land_segments/delta_time= 0..23313] [ /ds_surf_type= 0..4] (Type is Int8) attributes long_name: surface type (Type is String) units: 1 (Type is String) source: ATL03 ATBD (Type is String) valid_min: 0 (Type is Int8) valid_max: 1 (Type is Int8) contentType: referenceInformation (Type is String) description: Flags describing which surface types this interval is associated with. 0=not type, 1=is type. Order of array is land, ocean, sea ice, land ice, inland water. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_type is_type (Type is String) flag_values: 0, 1 (Type is Int8) brightness_flag[ /gt1l/land_segments/delta_time= 0..23313] (Type is Byte) attributes long_name: brightness flag (Type is String) units: 1 (Type is String) source: Land ATBD Brightness_flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: Flag indicating that the ground surface is bright (e.g. snow-covered or other bright surfaces) (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_bright_surface bright_surface Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) segment_landcover[ /gt1l/land_segments/delta_time= 0..23313] (Type is Byte) attributes long_name: segment landcover (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_landcover (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: UN-FAO Land Cover Surface type classification as reference from Copernicus Land Cover(ANC18) at the 100m resolution. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: No_data Closed_forest_evergreen_needle_leaf Closed_forest_deciduous_needle_leaf Closed_forest_evergreen_broad_leaf Closed_forest_deciduous_broad_leaf Closed_forest_mixed Closed_forest_unknown Open_forest_evergreen_needle_leaf Open_forest_deciduous_needle_leaf Open_forest_evergreen_broad_leaf Open_forest_deciduous_broad_leaf Open_forest_mixed Open_forest_unknown Shrubs Herbaceous Herbaceous_wetleand Moss_and_lichen Bare_sparse_vegetation Cultivated_and_managed_vegetation_agriculture Urban_built_up Snow_and_ice Permanent_water_bodies Open_sea Undetermined (Type is String) flag_values: 0, 111, 113, 112, 114, 115, 116, 121, 123, 122, 124, 125, 126, 20, 30, 90, 100, 60, 40, 50, 70, 80, 200, 255 (Type is Byte) ph_removal_flag[ /gt1l/land_segments/delta_time= 0..23313] (Type is Byte) attributes long_name: ph removal flag (Type is String) units: 1 (Type is String) source: ATBD Final photon classification QA (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Flag indicating more than ph_removal_percent_limit (default 50.0) removed from land segment due to failing QA tests (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) asr[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: apparent surface reflectance (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: auxiliaryInformation (Type is String) description: Apparent surface reflectance (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_atlas_land[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas land (Type is String) units: 1 (Type is String) source: Land ATBD Refine Ground Estimates (Type is String) contentType: referenceInformation (Type is String) description: Total vertical geolocation error due to ranging and local surface slope. The parameter is computed for ATL08 as described in equation 1.2 ATL08 ATBD. (Type is String) coordinates: delta_time latitude longitude (Type is String) segment_id_beg[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int32) attributes long_name: begin geolocation segment bin (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Geolocation segment number of the first photon in the land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_along[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas x (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Total along-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_along. Sigma_atlas_x is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_h[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: dem height (Type is String) units: meters (Type is String) source: Arctic, Antarctic, Global, MSS DEM (Type is String) contentType: referenceInformation (Type is String) description: Best available DEM (in priority of Arctic/Antarctic/Global/MSS) value at the geolocation point. Height is in meters above the WGS84 Ellipsoid. (Type is String) coordinates: delta_time latitude longitude (Type is String) beam_coelev[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: beam co-elevation (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Co-elevation (CE) is direction from vertical of the laser beam as seen by an observer located at the laser ground spot. (Type is String) coordinates: delta_time latitude longitude (Type is String) sat_flag[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int8) attributes long_name: saturation flag (Type is String) units: 1 (Type is String) source: ATL03, Land ATBD Saturation Flag (Type is String) valid_min: -1 (Type is Int8) valid_max: 127 (Type is Int8) contentType: auxiliaryInformation (Type is String) description: Flag derived from full_sat_fract on the ATL03 data product, averaged over 5 geosegments in 100m land segment (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_saturation_detected saturation_detected not_enough_valid_data Undetermined (Type is String) flag_values: 0, 1, -1, 127 (Type is Int8) sigma_topo[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas topo (Type is String) units: 1 (Type is String) source: Land ATBD Refine Ground Estimates (Type is String) contentType: referenceInformation (Type is String) description: Total uncertainty that include sigma_h plus geolocation uncertainty due to local slope (equation 1.3). The local slope is multiplied by the geolocation uncertainty factor. This will be used to determine the total vertical geolocation error due to ranging and local slope. (Type is String) coordinates: delta_time latitude longitude (Type is String) night_flag[ /gt1l/land_segments/delta_time= 0..23313] (Type is Byte) attributes long_name: night flag (Type is String) units: 1 (Type is String) source: Land ATBD Night_Flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Flag indicating the data were acquired in night conditions: 0=day, 1=night. Flag is derived from solar elevation at the geolocated segment. IF solar elevation is above threshold it is day, if not then it is night. Threshold is set in atlas_l3a_const_mod. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: day night Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) delta_time_beg[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float64) attributes long_name: delta time begin (Type is String) units: seconds since 2018-01-01 (Type is String) source: Derived (gps_seconds-gps_sec_offset) (Type is String) contentType: referenceInformation (Type is String) description: Time of the first photon contained within the data segment, in seconds since the ATLAS SDP GPS Epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_h[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: height uncertainty (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m) provided at the geolocation segment rate on ATL03. Sigma_h is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) last_seg_extend[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes long_name: last segment extended (Type is String) standard_name: last_seg_extend (Type is String) units: kilometers (Type is String) source: Land ATBD Preparing ATL03 data for input (Type is String) contentType: auxiliaryInformation (Type is String) description: The distance (km) that the last ATL08 processing segment in a file is either extended or overlapped with the previous ATL08 processing segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) column_od_asr[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Column optical depth from ASR (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: auxiliaryInformation (Type is String) description: Optical depth of atmosphere column based on apparent surface reflectance and the assumed actual surface reflectance. (Type is String) coordinates: delta_time latitude longitude (Type is String) atlas_pa[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: atlas pointing angle (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Off nadir pointing angle (in radians) of the satellite to increase spatial sampling in the non-polar regions. ATLAS_PA =radians(90degs-beam_coelev). (Type is String) coordinates: delta_time latitude longitude (Type is String) ph_ndx_beg[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int64) attributes long_name: photon index begin (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Index (1-based) within the photon-rate data (/land_segments/photons) of the first photon within this each land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) solar_elevation[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes long_name: solar elevation (Type is String) units: degrees (Type is String) source: ATL03 ATBD (Type is String) contentType: referenceInformation (Type is String) description: Solar Angle above or below the plane tangent to the ellipsoid surface at the laser spot. Positive values mean the sun is above the horizon, while negative values mean it is below the horizon. The effect of atmospheric refraction is not included. This is a low precision value, with approximately TBD degree accuracy. (Type is String) coordinates: delta_time latitude longitude (Type is String) latitude_20m[ /gt1l/land_segments/delta_time= 0..23313] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: latitude of 20m segments (Type is String) units: degree (Type is String) source: ATBD Geosegment latitude (Type is String) valid_min: -90. (Type is Float32) valid_max: 90. (Type is Float32) contentType: modelResult (Type is String) description: Center latitude of 20m geosegments within each 100m land segment. (Type is String) coordinates: latitude longitude delta_time (Type is String) cloud_fold_flag[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int8) attributes long_name: cloud folding flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: modelResult (Type is String) description: Flag that indicates this profile likely contains cloud signal folded down from above 15 km to the last 2-3 km of the profile. See ATL09 ATBD Table 3.9 for detailed flag value meanings. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_folding goes5_indicates profile_indicates both_indicate outside_limits (Type is String) flag_values: 0, 1, 2, 3, 127 (Type is Int8) n_seg_ph[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int32) attributes long_name: number of photons (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of photons within each land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) terrain_flg[ /gt1l/land_segments/delta_time= 0..23313] (Type is Byte) attributes long_name: terrain flag (Type is String) units: 1 (Type is String) source: Land ATBD Segment_terrain flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Terrain flag quality check to indicate a deviation above a threshold from the reference DEM height reported on the product. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) urban_flag[ /gt1l/land_segments/delta_time= 0..23313] (Type is Byte) attributes long_name: segment urban flag (Type is String) units: 1 (Type is String) source: Land ATBD Urban_flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: The urban flag indicates that a segment is likely located over an urban area as determined by coincident pixels in the Global Urban Footprint (GUF) 0.4 arcsecond product. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_urban urban Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) permafrost_alt[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: permafrost active layer thickness (Type is String) standard_name: permafrost_alt (Type is String) units: meters (Type is String) source: ESA CCI, ANC47 (Type is String) valid_min: 0. (Type is Float32) valid_max: 100. (Type is Float32) contentType: referenceInformation (Type is String) description: Permafrost active layer thickness (m) from ESA CCI 2019 northern hemisphere permafrost dataset (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_removal_flag[ /gt1l/land_segments/delta_time= 0..23313] (Type is Byte) attributes long_name: dem removal flag (Type is String) units: 1 (Type is String) source: ATBD Segment reference DEM removal flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: Flag indicating more than dem_removal_percent_limit (default 20.0) removed from land segment due to failing DEM-QA tests (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) h_dif_ref[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: h dif from reference (Type is String) units: meters (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) contentType: modelResult (Type is String) description: Difference between h_te_median and ref_DEM (Type is String) coordinates: delta_time latitude longitude (Type is String) canopy(Type is Group) attributes description: Contains height parameters based on the land algorithm. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) h_canopy[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: height canopy (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: 98% height of all the individual canopy relative heights for the segment above the estimated terrain surface. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) canopy_rh_conf[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int8) attributes units: 1 (Type is String) long_name: canopy relative height confidence (Type is String) source: Land/Veg ATBD Vegetation Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 2 (Type is Int8) contentType: modelResult (Type is String) description: Canopy relative height confidence flag based on percentage of ground and canopy photons within a segment: 0 (<5% canopy), 1 (>5% canopy, <5% ground), 2 (>5% canopy, >5% ground). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: <5%_canopy >=5%_canopy_<5%_ground >=5%_canopy_>=5%_ground (Type is String) flag_values: 0, 1, 2 (Type is Int8) h_median_canopy_abs[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute segment median canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The median of individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_min_canopy[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: minimum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of relative individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_mean_canopy_abs[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute mean canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Mean of the individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_median_canopy[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: median canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The median of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. This parameter should be equivalent to RH50 reported in the literature. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_abs[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute segment canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The 98% height of all the absolute individual canopy heights referenced above the WGS84 ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) toc_roughness[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: top of canopy roughness (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Standard deviation of the relative heights of all photons classified as top of canopy within the segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_min_canopy_abs[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute minimum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of absolute individual canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_dif_canopy[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy diff to median height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Difference between h_canopy and h_median_canopy (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_quad[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy quadratic mean (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The quadratic mean height of individual classified relative canopy photon heights above the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_20m[ /gt1l/land_segments/delta_time= 0..23313] [ /ds_geosegments= 0..4] (Type is Float32) attributes units: m (Type is String) _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy height 20m (Type is String) source: ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Canopy height for each 20m geosegment with each 100m land segment. (Type is String) coordinates: ../latitude ../longitude ../delta_time (Type is String) n_ca_photons[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int32) attributes long_name: number canopy photons (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The number of photons classified as canopy within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_can[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Canopy photon rate (Type is String) units: s^-1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Calculated photon rate of canopy photons within each 100m segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) centroid_height[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: centroid height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Optical centroid of all photons classified as either canopy or ground points within the segment. The heights used in this calculation are absolute heights above the reference ellipsoid. This parameter is equivalent to the centroid height produced ICESat GLA14. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) canopy_h_metrics_abs[ /gt1l/land_segments/delta_time= 0..23313] [ /ds_metrics= 0..17] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy absolute height metrics (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Height metrics based on the cumulative distribution of absolute canopy heights above the WGS84 Ellipsoid. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) can_noise[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy noise rate (Type is String) units: count/meter (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Number of noise photons calculated that fall within the canopy height for each 100 m segment based on ATL03 background rate parameters. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_mean_canopy[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mean canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Mean of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) subset_can_flag[ /gt1l/land_segments/delta_time= 0..23313] [ /ds_geosegments= 0..4] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: subset canopy flag (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: -1 (Type is Int8) valid_max: 1 (Type is Int8) contentType: modelResult (Type is String) description: Quality flag indicating the canopy photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: no_photon_data_within_geosegment no_canopy_photons_within_geosegment canopy_photons_present_within_geosegment (Type is String) flag_values: -1, 0, 1 (Type is Int8) canopy_h_metrics[ /gt1l/land_segments/delta_time= 0..23313] [ /ds_metrics= 0..17] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy height metrics (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Height metrics based on the cumulative distribution of relative canopy heights above the interpolated ground surface. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) n_toc_photons[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int32) attributes long_name: number top of canopy photons (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The number of photons classified as top of canopy within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_max_canopy_abs[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute maximum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Maximum of individual absolute canopy heights within segment referenced above the WGS84 ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_uncertainty[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment canopy height uncertainty (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: qualityInformation (Type is String) description: Uncertainty of the relative canopy heights for the segment. Incorporates all systematic uncertainties as well as uncertainty from errors of identified photons. See section 1 and equations 1.4 and 1.5 of the ATL08 ATBD. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_can_nr[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: noise reduced number of canopy photons (Type is String) units: s^-1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Noise removed photon canopy rate within each 100 m segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) can_quality_score[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int8) attributes units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: modelResult (Type is String) description: Canopy quality score based on coincident conditions, from ATL08 ATBD section titled "Canopy Quality Score". (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) _FillValue: 127 (Type is Int8) long_name: canopy quality score (Type is String) canopy_openness[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy openness (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Standard Deviation of all photons classified as canopy photons within the segment to provide inference of canopy openness. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_max_canopy[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: maximum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Relative maximum of individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. Should be equivalent to RH100 metric reported in the literature. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) segment_cover[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int16) attributes _FillValue: 32767 (Type is Int16) long_name: canopy cover percentage (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Average percentage value of the valid (value <= 100) Copernicus fractional cover product for each 100 m segment. This data is temporally static, and is the summation of forest and shrub land cover fractions. Source data from: https://land.copernicus.eu/en/products/global-dynamic-land-cover/copernicus-global-land-service-land-cover-100m-collection-3-epoch-2019-globe . (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) terrain(Type is Group) attributes description: Contains terrain parameters at a 100m aggregation. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) h_te_uncertainty[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: uncertainty of h_te_mean (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Uncertainty of the mean terrain height for the segment. This uncertainty incorporates all systematic uncertainties(e.g. timing orbits, geolocation,etc.) as well as uncertainty from errors of identified photons. This parameter is described in section 1, equation 1.4 in ATL08 ATBD. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_mean[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mean terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The mean of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_min[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: minimum terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_te[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Terrain photon rate (Type is String) units: s^-1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Calculated photon rate of terrain photons within each 100m segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_interp[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: interpolated terrain surface height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Interpolated terrain surface height above the WGS84 Ellipsoid at the midpoint of the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_max[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: maximum terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The maximum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_rh25[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes units: meters (Type is String) _FillValue: 3.402823466e+38 (Type is Float32) long_name: Terrain height 25% percentile (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The terrain elevation from the 25% height. The classified ground photons are sorted into a cumulative distribution and the height associated with the 25% height for that segment is reported. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_skew[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: skew of terrain heights (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The skewness of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_best_fit_20m[ /gt1l/land_segments/delta_time= 0..23313] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: best fit 20m (Type is String) units: m (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Best fit terrain height to center of each 20m geosegment within each 100m land segment. (Type is String) coordinates: ../latitude ../longitude ../delta_time (Type is String) h_te_median[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: median terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The median of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_best_fit[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain height best fit (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The best fit terrain elevation at the the mid-point location of each 100m segment. The mid-segment terrain elevation is determined by selecting the best of three fits- linear, 3rd order and 4th order polynomials - to the terrain photons and interpolating the elevation at the mid-point location of the 100 m segment. For the linear fit, a slope correction and weighting is applied to each ground photon based on the distance to the slope height at the center of the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_std[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain roughness (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The standard deviation of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) terrain_slope[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain slope (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The along-track slope of terrain, within each segment;computed by a linear fit of terrain classified photons. Slope is in units of delta height over delta along track distance. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) subset_te_flag[ /gt1l/land_segments/delta_time= 0..23313] [ /ds_geosegments= 0..4] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: subset terrain flag (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: -1 (Type is Int8) valid_max: 1 (Type is Int8) contentType: modelResult (Type is String) description: Quality flag indicating the terrain photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: no_photon_data_within_geosegment no_terrain_photons_within_geosegment terrain_photons_present_within_geosegment (Type is String) flag_values: -1, 0, 1 (Type is Int8) n_te_photons[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int32) attributes long_name: number of ground photons (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The number of the photons classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_mode[ /gt1l/land_segments/delta_time= 0..23313] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mode of terrain heights (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The mode of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) te_quality_score[ /gt1l/land_segments/delta_time= 0..23313] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: terrain quality score (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: modelResult (Type is String) description: Quality score based on coincident conditions, from ATL08 ATBD section titled "Terrain Quality Score". (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) signal_photons(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) description: Contains parameters related to individual photons. (Type is String) data_rate: Data are stored at the signal-photon classification rate. (Type is String) Dimensions: [ /gt1l/signal_photons/delta_time = 0..6833043 ] delta_time[ /gt1l/signal_photons/delta_time= 0..6833043] (Type is Float64) attributes long_name: delta time (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: ATL03 (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) classed_pc_indx[ /gt1l/signal_photons/delta_time= 0..6833043] (Type is Int32) attributes units: 1 (Type is String) long_name: indicies of classed photons (Type is String) source: Retained from prior a_alt_science_ph packet (Type is String) contentType: referenceInformation (Type is String) description: Index (1-based) of the ATL08 classified signal photon from the start of the ATL03 geolocation segment specified on the ATL08 product at the photon rate in the corresponding parameter, ph_segment_id. This index traces back to specific photon within a 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group. (Type is String) coordinates: delta_time (Type is String) ph_h[ /gt1l/signal_photons/delta_time= 0..6833043] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: relative photon height (Type is String) standard_name: height (Type is String) units: meters (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: physicalMeasurement (Type is String) description: Height of photons above interpolated land surface (Type is String) coordinates: delta_time (Type is String) d_flag[ /gt1l/signal_photons/delta_time= 0..6833043] (Type is Int8) attributes long_name: dragann flag (Type is String) units: 1 (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: qualityInformation (Type is String) description: Flag indicating the labeling of DRAGANN noise filtering for a given photon. (Type is String) coordinates: delta_time (Type is String) flag_meanings: noise signal (Type is String) flag_values: 0, 1 (Type is Int8) classed_pc_flag[ /gt1l/signal_photons/delta_time= 0..6833043] (Type is Int8) attributes long_name: photon land atbd classification (Type is String) units: 1 (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: modelResult (Type is String) description: Land Vegetation ATBD classification flag for each photon as either noise, ground, canopy, and top of canopy. 0 = noise, 1 = ground, 2 = canopy, or 3 = top of canopy. (Type is String) coordinates: delta_time (Type is String) flag_meanings: noise ground canopy top_of_canopy (Type is String) flag_values: 0, 1, 2, 3 (Type is Int8) ph_segment_id[ /gt1l/signal_photons/delta_time= 0..6833043] (Type is Int32) attributes long_name: segment id of photon (Type is String) units: 1 (Type is String) source: Retained from prior a_alt_science_ph packet (Type is String) contentType: referenceInformation (Type is String) description: Segment ID of photons tracing back to specific 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the photon on ATL03 is the segment_id, orbit, and classed_pc_indx. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group. (Type is String) coordinates: delta_time (Type is String) quality_assessment(Type is Group) attributes description: Contains quality assessment data. This may include QA counters, QA along-track data and/or QA summary data. (Type is String) qa_granule_fail_reason[ 0..0] (Type is Int32) attributes long_name: Granule Failure Reason (Type is String) units: 1 (Type is String) source: Operations (Type is String) valid_min: 0 (Type is Int32) valid_max: 5 (Type is Int32) contentType: qualityInformation (Type is String) description: Flag indicating granule failure reason. 0=no failure; 1=processing error; 2=Insufficient output data was generated; 3=TBD Failure; 4=TBD_Failure; 5=other failure. (Type is String) flag_meanings: no_failure PROCESS_ERROR INSUFFICIENT_OUTPUT failure_3 failure_4 OTHER_FAILURE (Type is String) flag_values: 0, 1, 2, 3, 4, 5 (Type is Int32) qa_granule_pass_fail[ 0..0] (Type is Int32) attributes long_name: Granule Pass Flag (Type is String) units: 1 (Type is String) source: Operations (Type is String) valid_min: 0 (Type is Int32) valid_max: 1 (Type is Int32) contentType: qualityInformation (Type is String) description: Flag indicating granule quality. 0=granule passes automatic QA. 1=granule fails automatic QA. (Type is String) flag_meanings: PASS FAIL (Type is String) flag_values: 0, 1 (Type is Int32) gt3l(Type is Group) attributes atlas_pce: pce3 (Type is String) atlas_beam_type: strong (Type is String) groundtrack_id: gt3l (Type is String) atmosphere_profile: profile_3 (Type is String) atlas_spot_number: 5 (Type is String) sc_orientation: Backward (Type is String) land_segments(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) description: Contains data categorized as land at 100 meter intervals. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) Dimensions: [ /gt3l/land_segments/delta_time = 0..22390 ] longitude[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes long_name: longitude (Type is String) standard_name: longitude (Type is String) units: degrees (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) valid_min: -180. (Type is Float32) valid_max: 180. (Type is Float32) contentType: modelResult (Type is String) description: Longitude of the center-most signal photon within each segment. (Type is String) coordinates: delta_time latitude (Type is String) latitude[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes long_name: latitude (Type is String) standard_name: latitude (Type is String) units: degrees (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) valid_min: -90. (Type is Float32) valid_max: 90. (Type is Float32) contentType: modelResult (Type is String) description: Latitude of the center-most signal photon within each segment. (Type is String) coordinates: delta_time longitude (Type is String) delta_time[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float64) attributes long_name: mean_pass_time (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) contentType: referenceInformation (Type is String) description: Mean time for the segment in number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: latitude longitude (Type is String) rgt[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int16) attributes long_name: reference ground track (Type is String) units: 1 (Type is String) source: Operations (Type is String) valid_min: 1 (Type is Int16) valid_max: 1387 (Type is Int16) contentType: referenceInformation (Type is String) description: The reference ground track (RGT) is the track on the earth at which a specified unit vector within the observatory is pointed. Under nominal operating conditions, there will be no data collected along the RGT, as the RGT is spanned by GT3 and GT4. During slews or off-pointing, it is possible that ground tracks may intersect the RGT. The ICESat-2 mission has 1387 RGTs. (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_flag[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int8) attributes long_name: dem source flag (Type is String) units: 1 (Type is String) source: Atmosphere ATBD (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: referenceInformation (Type is String) description: Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=Global, 3=MSS, 4=Antarctic. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: none arctic global mss antarctic Undetermined (Type is String) flag_values: 0, 1, 2, 3, 4, 127 (Type is Int8) msw_flag[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int8) attributes long_name: multiple scattering warning flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: qualityInformation (Type is String) description: Multiple Scattering Warning flag. If no layers were detected, then msw_flag = 0. If blowing snow is detected and its estimated optical depth is greater than or equal to 0.5, then msw_flag = 5. If the blowing snow optical depth is less than 0.5, then msw_flag = 4. If no blowing snow is detected but there are cloud or aerosol layers detected, the msw_flag assumes values of 1 to 3 based on the height of the bottom of the lowest layer: < 1 km, msw_flag = 3; 1-3 km, msw_flag = 2; > 3km, msw_flag = 1. A value of 127 indicates that the signal to noise of the data was too low to reliably ascertain the presence of cloud or blowing snow. We expect values of 127 to occur only during daylight. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: cannot_determine no_layers layer_gt_3km layer_between_1_and_3_km layer_lt_1km blow_snow_od_lt_0.5 blow_snow_od_gt_0.5 (Type is String) flag_values: 127, 0, 1, 2, 3, 4, 5 (Type is Int8) permafrost_prob[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: permafrost probaility (Type is String) standard_name: permafrost_prob (Type is String) units: percent (Type is String) source: ESA CCI, ANC47 (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: referenceInformation (Type is String) description: Permafrost probability (0 - 100) derived via percent of permafrost within pixel cell area in ESA CCI 2019 northern hemisphere permafrost dataset (Type is String) coordinates: delta_time latitude longitude (Type is String) cloud_flag_atm[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: cloud flag atm (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 10 (Type is Int8) contentType: qualityInformation (Type is String) description: Cloud confidence flag from ATL09 that indicates the number of cloud or aerosol layers identified in each 25Hz atmospheric profile. If the flag is greater than 0, aerosols or clouds could be present. Valid range is 0 - 10. (Type is String) coordinates: delta_time latitude longitude (Type is String) snr[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: signal to noise ratio (Type is String) units: 1 (Type is String) source: ATBD Noise filtering via DRAGANN (Type is String) contentType: modelResult (Type is String) description: The signal to noise ratio of geolocated photons as determined by the ratio of the superset of ATL03 signal and DRAGANN found signal photons used for processing the ATL08 segments to the background photons (i.e. noise) within the same ATL08 segments. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_across[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas y (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Total cross-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_across. Sigma_atlas_y is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) layer_flag[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int8) attributes long_name: consolidated cloud flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: modelResult (Type is String) description: This flag is a combination of multiple flags (cloud_flag_atm, cloud_flag_asr, and bsnow_con) and takes daytime/nighttime into consideration. A value of 1 means clouds or blowing snow are likely present. A value of 0 indicates the likely absence of clouds or blowing snow. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: likely_clear likely_cloudy (Type is String) flag_values: 0, 1 (Type is Int8) segment_snowcover[ /gt3l/land_segments/delta_time= 0..22390] (Type is Byte) attributes long_name: segment snowcover (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_snowcover (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Daily snow/ice cover from ATL09 at the 25 Hz rate(275m) indicating likely presence of snow and ice within each segment. 0=ice free water; 1=snow free land; 2=snow; 3=ice. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: ice_free_water snow_free_land snow ice Undetermined (Type is String) flag_values: 0, 1, 2, 3, 255 (Type is Byte) beam_azimuth[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: beam azimuth (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Azimuth(in radians) of the unit pointing vector for the reference photon in the local ENU frame in radians. The angle is measured from north and positive towards East. (Type is String) coordinates: delta_time latitude longitude (Type is String) solar_azimuth[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes long_name: solar azimuth (Type is String) units: degrees_east (Type is String) source: ATL03 ATBD (Type is String) contentType: referenceInformation (Type is String) description: The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot. (Type is String) coordinates: delta_time latitude longitude (Type is String) psf_flag[ /gt3l/land_segments/delta_time= 0..22390] (Type is Byte) attributes long_name: point spread function flag (Type is String) units: 1 (Type is String) source: Land/Veg ATBD Refine Ground Estimates (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: referenceInformation (Type is String) description: Flag is set to 1 if the point spread function (computed as sigma_atlas_land) has exceeded the threshold (1 m) (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) segment_watermask[ /gt3l/land_segments/delta_time= 0..22390] (Type is Byte) attributes long_name: segment watermask (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_watermask (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Water mask(i.e. flag) indicating inland water as referenced from the Global Raster Water Mask(ANC33) at 250 m spatial resolution. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_water water Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) delta_time_end[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float64) attributes long_name: delta time end (Type is String) units: seconds since 2018-01-01 (Type is String) source: Derived (gps_seconds-gps_sec_offset) (Type is String) contentType: referenceInformation (Type is String) description: Time of the last photon contained within the data segment, in seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: delta_time latitude longitude (Type is String) segment_id_end[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int32) attributes long_name: end geolocation segment bin (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Geolocation segment number of the last photon in the land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) longitude_20m[ /gt3l/land_segments/delta_time= 0..22390] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: longitude of 20m segments (Type is String) units: degree (Type is String) source: ATBD Geosegment longitude (Type is String) valid_min: -180. (Type is Float32) valid_max: 180. (Type is Float32) contentType: modelResult (Type is String) description: Center longitude of 20m geosegments within each 100m land segment. (Type is String) coordinates: latitude longitude delta_time (Type is String) surf_type[ /gt3l/land_segments/delta_time= 0..22390] [ /ds_surf_type= 0..4] (Type is Int8) attributes long_name: surface type (Type is String) units: 1 (Type is String) source: ATL03 ATBD (Type is String) valid_min: 0 (Type is Int8) valid_max: 1 (Type is Int8) contentType: referenceInformation (Type is String) description: Flags describing which surface types this interval is associated with. 0=not type, 1=is type. Order of array is land, ocean, sea ice, land ice, inland water. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_type is_type (Type is String) flag_values: 0, 1 (Type is Int8) brightness_flag[ /gt3l/land_segments/delta_time= 0..22390] (Type is Byte) attributes long_name: brightness flag (Type is String) units: 1 (Type is String) source: Land ATBD Brightness_flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: Flag indicating that the ground surface is bright (e.g. snow-covered or other bright surfaces) (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_bright_surface bright_surface Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) segment_landcover[ /gt3l/land_segments/delta_time= 0..22390] (Type is Byte) attributes long_name: segment landcover (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_landcover (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: UN-FAO Land Cover Surface type classification as reference from Copernicus Land Cover(ANC18) at the 100m resolution. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: No_data Closed_forest_evergreen_needle_leaf Closed_forest_deciduous_needle_leaf Closed_forest_evergreen_broad_leaf Closed_forest_deciduous_broad_leaf Closed_forest_mixed Closed_forest_unknown Open_forest_evergreen_needle_leaf Open_forest_deciduous_needle_leaf Open_forest_evergreen_broad_leaf Open_forest_deciduous_broad_leaf Open_forest_mixed Open_forest_unknown Shrubs Herbaceous Herbaceous_wetleand Moss_and_lichen Bare_sparse_vegetation Cultivated_and_managed_vegetation_agriculture Urban_built_up Snow_and_ice Permanent_water_bodies Open_sea Undetermined (Type is String) flag_values: 0, 111, 113, 112, 114, 115, 116, 121, 123, 122, 124, 125, 126, 20, 30, 90, 100, 60, 40, 50, 70, 80, 200, 255 (Type is Byte) ph_removal_flag[ /gt3l/land_segments/delta_time= 0..22390] (Type is Byte) attributes long_name: ph removal flag (Type is String) units: 1 (Type is String) source: ATBD Final photon classification QA (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Flag indicating more than ph_removal_percent_limit (default 50.0) removed from land segment due to failing QA tests (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) asr[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: apparent surface reflectance (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: auxiliaryInformation (Type is String) description: Apparent surface reflectance (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_atlas_land[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas land (Type is String) units: 1 (Type is String) source: Land ATBD Refine Ground Estimates (Type is String) contentType: referenceInformation (Type is String) description: Total vertical geolocation error due to ranging and local surface slope. The parameter is computed for ATL08 as described in equation 1.2 ATL08 ATBD. (Type is String) coordinates: delta_time latitude longitude (Type is String) segment_id_beg[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int32) attributes long_name: begin geolocation segment bin (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Geolocation segment number of the first photon in the land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_along[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas x (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Total along-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_along. Sigma_atlas_x is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_h[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: dem height (Type is String) units: meters (Type is String) source: Arctic, Antarctic, Global, MSS DEM (Type is String) contentType: referenceInformation (Type is String) description: Best available DEM (in priority of Arctic/Antarctic/Global/MSS) value at the geolocation point. Height is in meters above the WGS84 Ellipsoid. (Type is String) coordinates: delta_time latitude longitude (Type is String) beam_coelev[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: beam co-elevation (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Co-elevation (CE) is direction from vertical of the laser beam as seen by an observer located at the laser ground spot. (Type is String) coordinates: delta_time latitude longitude (Type is String) sat_flag[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int8) attributes long_name: saturation flag (Type is String) units: 1 (Type is String) source: ATL03, Land ATBD Saturation Flag (Type is String) valid_min: -1 (Type is Int8) valid_max: 127 (Type is Int8) contentType: auxiliaryInformation (Type is String) description: Flag derived from full_sat_fract on the ATL03 data product, averaged over 5 geosegments in 100m land segment (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_saturation_detected saturation_detected not_enough_valid_data Undetermined (Type is String) flag_values: 0, 1, -1, 127 (Type is Int8) sigma_topo[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas topo (Type is String) units: 1 (Type is String) source: Land ATBD Refine Ground Estimates (Type is String) contentType: referenceInformation (Type is String) description: Total uncertainty that include sigma_h plus geolocation uncertainty due to local slope (equation 1.3). The local slope is multiplied by the geolocation uncertainty factor. This will be used to determine the total vertical geolocation error due to ranging and local slope. (Type is String) coordinates: delta_time latitude longitude (Type is String) night_flag[ /gt3l/land_segments/delta_time= 0..22390] (Type is Byte) attributes long_name: night flag (Type is String) units: 1 (Type is String) source: Land ATBD Night_Flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Flag indicating the data were acquired in night conditions: 0=day, 1=night. Flag is derived from solar elevation at the geolocated segment. IF solar elevation is above threshold it is day, if not then it is night. Threshold is set in atlas_l3a_const_mod. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: day night Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) delta_time_beg[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float64) attributes long_name: delta time begin (Type is String) units: seconds since 2018-01-01 (Type is String) source: Derived (gps_seconds-gps_sec_offset) (Type is String) contentType: referenceInformation (Type is String) description: Time of the first photon contained within the data segment, in seconds since the ATLAS SDP GPS Epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_h[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: height uncertainty (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m) provided at the geolocation segment rate on ATL03. Sigma_h is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) last_seg_extend[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes long_name: last segment extended (Type is String) standard_name: last_seg_extend (Type is String) units: kilometers (Type is String) source: Land ATBD Preparing ATL03 data for input (Type is String) contentType: auxiliaryInformation (Type is String) description: The distance (km) that the last ATL08 processing segment in a file is either extended or overlapped with the previous ATL08 processing segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) column_od_asr[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Column optical depth from ASR (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: auxiliaryInformation (Type is String) description: Optical depth of atmosphere column based on apparent surface reflectance and the assumed actual surface reflectance. (Type is String) coordinates: delta_time latitude longitude (Type is String) atlas_pa[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: atlas pointing angle (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Off nadir pointing angle (in radians) of the satellite to increase spatial sampling in the non-polar regions. ATLAS_PA =radians(90degs-beam_coelev). (Type is String) coordinates: delta_time latitude longitude (Type is String) ph_ndx_beg[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int64) attributes long_name: photon index begin (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Index (1-based) within the photon-rate data (/land_segments/photons) of the first photon within this each land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) solar_elevation[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes long_name: solar elevation (Type is String) units: degrees (Type is String) source: ATL03 ATBD (Type is String) contentType: referenceInformation (Type is String) description: Solar Angle above or below the plane tangent to the ellipsoid surface at the laser spot. Positive values mean the sun is above the horizon, while negative values mean it is below the horizon. The effect of atmospheric refraction is not included. This is a low precision value, with approximately TBD degree accuracy. (Type is String) coordinates: delta_time latitude longitude (Type is String) latitude_20m[ /gt3l/land_segments/delta_time= 0..22390] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: latitude of 20m segments (Type is String) units: degree (Type is String) source: ATBD Geosegment latitude (Type is String) valid_min: -90. (Type is Float32) valid_max: 90. (Type is Float32) contentType: modelResult (Type is String) description: Center latitude of 20m geosegments within each 100m land segment. (Type is String) coordinates: latitude longitude delta_time (Type is String) cloud_fold_flag[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int8) attributes long_name: cloud folding flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: modelResult (Type is String) description: Flag that indicates this profile likely contains cloud signal folded down from above 15 km to the last 2-3 km of the profile. See ATL09 ATBD Table 3.9 for detailed flag value meanings. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_folding goes5_indicates profile_indicates both_indicate outside_limits (Type is String) flag_values: 0, 1, 2, 3, 127 (Type is Int8) n_seg_ph[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int32) attributes long_name: number of photons (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of photons within each land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) terrain_flg[ /gt3l/land_segments/delta_time= 0..22390] (Type is Byte) attributes long_name: terrain flag (Type is String) units: 1 (Type is String) source: Land ATBD Segment_terrain flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Terrain flag quality check to indicate a deviation above a threshold from the reference DEM height reported on the product. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) urban_flag[ /gt3l/land_segments/delta_time= 0..22390] (Type is Byte) attributes long_name: segment urban flag (Type is String) units: 1 (Type is String) source: Land ATBD Urban_flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: The urban flag indicates that a segment is likely located over an urban area as determined by coincident pixels in the Global Urban Footprint (GUF) 0.4 arcsecond product. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_urban urban Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) permafrost_alt[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: permafrost active layer thickness (Type is String) standard_name: permafrost_alt (Type is String) units: meters (Type is String) source: ESA CCI, ANC47 (Type is String) valid_min: 0. (Type is Float32) valid_max: 100. (Type is Float32) contentType: referenceInformation (Type is String) description: Permafrost active layer thickness (m) from ESA CCI 2019 northern hemisphere permafrost dataset (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_removal_flag[ /gt3l/land_segments/delta_time= 0..22390] (Type is Byte) attributes long_name: dem removal flag (Type is String) units: 1 (Type is String) source: ATBD Segment reference DEM removal flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: Flag indicating more than dem_removal_percent_limit (default 20.0) removed from land segment due to failing DEM-QA tests (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) h_dif_ref[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: h dif from reference (Type is String) units: meters (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) contentType: modelResult (Type is String) description: Difference between h_te_median and ref_DEM (Type is String) coordinates: delta_time latitude longitude (Type is String) canopy(Type is Group) attributes description: Contains height parameters based on the land algorithm. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) h_canopy[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: height canopy (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: 98% height of all the individual canopy relative heights for the segment above the estimated terrain surface. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) canopy_rh_conf[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int8) attributes units: 1 (Type is String) long_name: canopy relative height confidence (Type is String) source: Land/Veg ATBD Vegetation Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 2 (Type is Int8) contentType: modelResult (Type is String) description: Canopy relative height confidence flag based on percentage of ground and canopy photons within a segment: 0 (<5% canopy), 1 (>5% canopy, <5% ground), 2 (>5% canopy, >5% ground). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: <5%_canopy >=5%_canopy_<5%_ground >=5%_canopy_>=5%_ground (Type is String) flag_values: 0, 1, 2 (Type is Int8) h_median_canopy_abs[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute segment median canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The median of individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_min_canopy[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: minimum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of relative individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_mean_canopy_abs[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute mean canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Mean of the individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_median_canopy[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: median canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The median of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. This parameter should be equivalent to RH50 reported in the literature. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_abs[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute segment canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The 98% height of all the absolute individual canopy heights referenced above the WGS84 ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) toc_roughness[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: top of canopy roughness (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Standard deviation of the relative heights of all photons classified as top of canopy within the segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_min_canopy_abs[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute minimum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of absolute individual canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_dif_canopy[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy diff to median height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Difference between h_canopy and h_median_canopy (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_quad[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy quadratic mean (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The quadratic mean height of individual classified relative canopy photon heights above the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_20m[ /gt3l/land_segments/delta_time= 0..22390] [ /ds_geosegments= 0..4] (Type is Float32) attributes units: m (Type is String) _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy height 20m (Type is String) source: ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Canopy height for each 20m geosegment with each 100m land segment. (Type is String) coordinates: ../latitude ../longitude ../delta_time (Type is String) n_ca_photons[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int32) attributes long_name: number canopy photons (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The number of photons classified as canopy within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_can[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Canopy photon rate (Type is String) units: s^-1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Calculated photon rate of canopy photons within each 100m segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) centroid_height[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: centroid height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Optical centroid of all photons classified as either canopy or ground points within the segment. The heights used in this calculation are absolute heights above the reference ellipsoid. This parameter is equivalent to the centroid height produced ICESat GLA14. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) canopy_h_metrics_abs[ /gt3l/land_segments/delta_time= 0..22390] [ /ds_metrics= 0..17] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy absolute height metrics (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Height metrics based on the cumulative distribution of absolute canopy heights above the WGS84 Ellipsoid. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) can_noise[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy noise rate (Type is String) units: count/meter (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Number of noise photons calculated that fall within the canopy height for each 100 m segment based on ATL03 background rate parameters. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_mean_canopy[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mean canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Mean of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) subset_can_flag[ /gt3l/land_segments/delta_time= 0..22390] [ /ds_geosegments= 0..4] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: subset canopy flag (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: -1 (Type is Int8) valid_max: 1 (Type is Int8) contentType: modelResult (Type is String) description: Quality flag indicating the canopy photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: no_photon_data_within_geosegment no_canopy_photons_within_geosegment canopy_photons_present_within_geosegment (Type is String) flag_values: -1, 0, 1 (Type is Int8) canopy_h_metrics[ /gt3l/land_segments/delta_time= 0..22390] [ /ds_metrics= 0..17] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy height metrics (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Height metrics based on the cumulative distribution of relative canopy heights above the interpolated ground surface. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) n_toc_photons[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int32) attributes long_name: number top of canopy photons (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The number of photons classified as top of canopy within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_max_canopy_abs[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute maximum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Maximum of individual absolute canopy heights within segment referenced above the WGS84 ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_uncertainty[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment canopy height uncertainty (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: qualityInformation (Type is String) description: Uncertainty of the relative canopy heights for the segment. Incorporates all systematic uncertainties as well as uncertainty from errors of identified photons. See section 1 and equations 1.4 and 1.5 of the ATL08 ATBD. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_can_nr[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: noise reduced number of canopy photons (Type is String) units: s^-1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Noise removed photon canopy rate within each 100 m segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) can_quality_score[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int8) attributes units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: modelResult (Type is String) description: Canopy quality score based on coincident conditions, from ATL08 ATBD section titled "Canopy Quality Score". (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) _FillValue: 127 (Type is Int8) long_name: canopy quality score (Type is String) canopy_openness[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy openness (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Standard Deviation of all photons classified as canopy photons within the segment to provide inference of canopy openness. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_max_canopy[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: maximum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Relative maximum of individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. Should be equivalent to RH100 metric reported in the literature. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) segment_cover[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int16) attributes _FillValue: 32767 (Type is Int16) long_name: canopy cover percentage (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Average percentage value of the valid (value <= 100) Copernicus fractional cover product for each 100 m segment. This data is temporally static, and is the summation of forest and shrub land cover fractions. Source data from: https://land.copernicus.eu/en/products/global-dynamic-land-cover/copernicus-global-land-service-land-cover-100m-collection-3-epoch-2019-globe . (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) terrain(Type is Group) attributes description: Contains terrain parameters at a 100m aggregation. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) h_te_uncertainty[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: uncertainty of h_te_mean (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Uncertainty of the mean terrain height for the segment. This uncertainty incorporates all systematic uncertainties(e.g. timing orbits, geolocation,etc.) as well as uncertainty from errors of identified photons. This parameter is described in section 1, equation 1.4 in ATL08 ATBD. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_mean[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mean terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The mean of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_min[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: minimum terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_te[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Terrain photon rate (Type is String) units: s^-1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Calculated photon rate of terrain photons within each 100m segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_interp[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: interpolated terrain surface height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Interpolated terrain surface height above the WGS84 Ellipsoid at the midpoint of the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_max[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: maximum terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The maximum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_rh25[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes units: meters (Type is String) _FillValue: 3.402823466e+38 (Type is Float32) long_name: Terrain height 25% percentile (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The terrain elevation from the 25% height. The classified ground photons are sorted into a cumulative distribution and the height associated with the 25% height for that segment is reported. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_skew[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: skew of terrain heights (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The skewness of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_best_fit_20m[ /gt3l/land_segments/delta_time= 0..22390] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: best fit 20m (Type is String) units: m (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Best fit terrain height to center of each 20m geosegment within each 100m land segment. (Type is String) coordinates: ../latitude ../longitude ../delta_time (Type is String) h_te_median[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: median terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The median of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_best_fit[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain height best fit (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The best fit terrain elevation at the the mid-point location of each 100m segment. The mid-segment terrain elevation is determined by selecting the best of three fits- linear, 3rd order and 4th order polynomials - to the terrain photons and interpolating the elevation at the mid-point location of the 100 m segment. For the linear fit, a slope correction and weighting is applied to each ground photon based on the distance to the slope height at the center of the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_std[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain roughness (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The standard deviation of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) terrain_slope[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain slope (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The along-track slope of terrain, within each segment;computed by a linear fit of terrain classified photons. Slope is in units of delta height over delta along track distance. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) subset_te_flag[ /gt3l/land_segments/delta_time= 0..22390] [ /ds_geosegments= 0..4] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: subset terrain flag (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: -1 (Type is Int8) valid_max: 1 (Type is Int8) contentType: modelResult (Type is String) description: Quality flag indicating the terrain photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: no_photon_data_within_geosegment no_terrain_photons_within_geosegment terrain_photons_present_within_geosegment (Type is String) flag_values: -1, 0, 1 (Type is Int8) n_te_photons[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int32) attributes long_name: number of ground photons (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The number of the photons classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_mode[ /gt3l/land_segments/delta_time= 0..22390] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mode of terrain heights (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The mode of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) te_quality_score[ /gt3l/land_segments/delta_time= 0..22390] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: terrain quality score (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: modelResult (Type is String) description: Quality score based on coincident conditions, from ATL08 ATBD section titled "Terrain Quality Score". (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) signal_photons(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) description: Contains parameters related to individual photons. (Type is String) data_rate: Data are stored at the signal-photon classification rate. (Type is String) Dimensions: [ /gt3l/signal_photons/delta_time = 0..6240448 ] delta_time[ /gt3l/signal_photons/delta_time= 0..6240448] (Type is Float64) attributes long_name: delta time (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: ATL03 (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) classed_pc_indx[ /gt3l/signal_photons/delta_time= 0..6240448] (Type is Int32) attributes units: 1 (Type is String) long_name: indicies of classed photons (Type is String) source: Retained from prior a_alt_science_ph packet (Type is String) contentType: referenceInformation (Type is String) description: Index (1-based) of the ATL08 classified signal photon from the start of the ATL03 geolocation segment specified on the ATL08 product at the photon rate in the corresponding parameter, ph_segment_id. This index traces back to specific photon within a 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group. (Type is String) coordinates: delta_time (Type is String) ph_h[ /gt3l/signal_photons/delta_time= 0..6240448] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: relative photon height (Type is String) standard_name: height (Type is String) units: meters (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: physicalMeasurement (Type is String) description: Height of photons above interpolated land surface (Type is String) coordinates: delta_time (Type is String) d_flag[ /gt3l/signal_photons/delta_time= 0..6240448] (Type is Int8) attributes long_name: dragann flag (Type is String) units: 1 (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: qualityInformation (Type is String) description: Flag indicating the labeling of DRAGANN noise filtering for a given photon. (Type is String) coordinates: delta_time (Type is String) flag_meanings: noise signal (Type is String) flag_values: 0, 1 (Type is Int8) classed_pc_flag[ /gt3l/signal_photons/delta_time= 0..6240448] (Type is Int8) attributes long_name: photon land atbd classification (Type is String) units: 1 (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: modelResult (Type is String) description: Land Vegetation ATBD classification flag for each photon as either noise, ground, canopy, and top of canopy. 0 = noise, 1 = ground, 2 = canopy, or 3 = top of canopy. (Type is String) coordinates: delta_time (Type is String) flag_meanings: noise ground canopy top_of_canopy (Type is String) flag_values: 0, 1, 2, 3 (Type is Int8) ph_segment_id[ /gt3l/signal_photons/delta_time= 0..6240448] (Type is Int32) attributes long_name: segment id of photon (Type is String) units: 1 (Type is String) source: Retained from prior a_alt_science_ph packet (Type is String) contentType: referenceInformation (Type is String) description: Segment ID of photons tracing back to specific 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the photon on ATL03 is the segment_id, orbit, and classed_pc_indx. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group. (Type is String) coordinates: delta_time (Type is String) gt2l(Type is Group) attributes atlas_pce: pce2 (Type is String) atlas_beam_type: strong (Type is String) groundtrack_id: gt2l (Type is String) atmosphere_profile: profile_2 (Type is String) atlas_spot_number: 3 (Type is String) sc_orientation: Backward (Type is String) land_segments(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) description: Contains data categorized as land at 100 meter intervals. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) Dimensions: [ /gt2l/land_segments/delta_time = 0..22710 ] longitude[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes long_name: longitude (Type is String) standard_name: longitude (Type is String) units: degrees (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) valid_min: -180. (Type is Float32) valid_max: 180. (Type is Float32) contentType: modelResult (Type is String) description: Longitude of the center-most signal photon within each segment. (Type is String) coordinates: delta_time latitude (Type is String) latitude[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes long_name: latitude (Type is String) standard_name: latitude (Type is String) units: degrees (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) valid_min: -90. (Type is Float32) valid_max: 90. (Type is Float32) contentType: modelResult (Type is String) description: Latitude of the center-most signal photon within each segment. (Type is String) coordinates: delta_time longitude (Type is String) delta_time[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float64) attributes long_name: mean_pass_time (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) contentType: referenceInformation (Type is String) description: Mean time for the segment in number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: latitude longitude (Type is String) rgt[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int16) attributes long_name: reference ground track (Type is String) units: 1 (Type is String) source: Operations (Type is String) valid_min: 1 (Type is Int16) valid_max: 1387 (Type is Int16) contentType: referenceInformation (Type is String) description: The reference ground track (RGT) is the track on the earth at which a specified unit vector within the observatory is pointed. Under nominal operating conditions, there will be no data collected along the RGT, as the RGT is spanned by GT3 and GT4. During slews or off-pointing, it is possible that ground tracks may intersect the RGT. The ICESat-2 mission has 1387 RGTs. (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_flag[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int8) attributes long_name: dem source flag (Type is String) units: 1 (Type is String) source: Atmosphere ATBD (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: referenceInformation (Type is String) description: Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=Global, 3=MSS, 4=Antarctic. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: none arctic global mss antarctic Undetermined (Type is String) flag_values: 0, 1, 2, 3, 4, 127 (Type is Int8) msw_flag[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int8) attributes long_name: multiple scattering warning flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: qualityInformation (Type is String) description: Multiple Scattering Warning flag. If no layers were detected, then msw_flag = 0. If blowing snow is detected and its estimated optical depth is greater than or equal to 0.5, then msw_flag = 5. If the blowing snow optical depth is less than 0.5, then msw_flag = 4. If no blowing snow is detected but there are cloud or aerosol layers detected, the msw_flag assumes values of 1 to 3 based on the height of the bottom of the lowest layer: < 1 km, msw_flag = 3; 1-3 km, msw_flag = 2; > 3km, msw_flag = 1. A value of 127 indicates that the signal to noise of the data was too low to reliably ascertain the presence of cloud or blowing snow. We expect values of 127 to occur only during daylight. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: cannot_determine no_layers layer_gt_3km layer_between_1_and_3_km layer_lt_1km blow_snow_od_lt_0.5 blow_snow_od_gt_0.5 (Type is String) flag_values: 127, 0, 1, 2, 3, 4, 5 (Type is Int8) permafrost_prob[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: permafrost probaility (Type is String) standard_name: permafrost_prob (Type is String) units: percent (Type is String) source: ESA CCI, ANC47 (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: referenceInformation (Type is String) description: Permafrost probability (0 - 100) derived via percent of permafrost within pixel cell area in ESA CCI 2019 northern hemisphere permafrost dataset (Type is String) coordinates: delta_time latitude longitude (Type is String) cloud_flag_atm[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: cloud flag atm (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 10 (Type is Int8) contentType: qualityInformation (Type is String) description: Cloud confidence flag from ATL09 that indicates the number of cloud or aerosol layers identified in each 25Hz atmospheric profile. If the flag is greater than 0, aerosols or clouds could be present. Valid range is 0 - 10. (Type is String) coordinates: delta_time latitude longitude (Type is String) snr[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: signal to noise ratio (Type is String) units: 1 (Type is String) source: ATBD Noise filtering via DRAGANN (Type is String) contentType: modelResult (Type is String) description: The signal to noise ratio of geolocated photons as determined by the ratio of the superset of ATL03 signal and DRAGANN found signal photons used for processing the ATL08 segments to the background photons (i.e. noise) within the same ATL08 segments. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_across[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas y (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Total cross-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_across. Sigma_atlas_y is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) layer_flag[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int8) attributes long_name: consolidated cloud flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: modelResult (Type is String) description: This flag is a combination of multiple flags (cloud_flag_atm, cloud_flag_asr, and bsnow_con) and takes daytime/nighttime into consideration. A value of 1 means clouds or blowing snow are likely present. A value of 0 indicates the likely absence of clouds or blowing snow. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: likely_clear likely_cloudy (Type is String) flag_values: 0, 1 (Type is Int8) segment_snowcover[ /gt2l/land_segments/delta_time= 0..22710] (Type is Byte) attributes long_name: segment snowcover (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_snowcover (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Daily snow/ice cover from ATL09 at the 25 Hz rate(275m) indicating likely presence of snow and ice within each segment. 0=ice free water; 1=snow free land; 2=snow; 3=ice. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: ice_free_water snow_free_land snow ice Undetermined (Type is String) flag_values: 0, 1, 2, 3, 255 (Type is Byte) beam_azimuth[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: beam azimuth (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Azimuth(in radians) of the unit pointing vector for the reference photon in the local ENU frame in radians. The angle is measured from north and positive towards East. (Type is String) coordinates: delta_time latitude longitude (Type is String) solar_azimuth[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes long_name: solar azimuth (Type is String) units: degrees_east (Type is String) source: ATL03 ATBD (Type is String) contentType: referenceInformation (Type is String) description: The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot. (Type is String) coordinates: delta_time latitude longitude (Type is String) psf_flag[ /gt2l/land_segments/delta_time= 0..22710] (Type is Byte) attributes long_name: point spread function flag (Type is String) units: 1 (Type is String) source: Land/Veg ATBD Refine Ground Estimates (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: referenceInformation (Type is String) description: Flag is set to 1 if the point spread function (computed as sigma_atlas_land) has exceeded the threshold (1 m) (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) segment_watermask[ /gt2l/land_segments/delta_time= 0..22710] (Type is Byte) attributes long_name: segment watermask (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_watermask (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Water mask(i.e. flag) indicating inland water as referenced from the Global Raster Water Mask(ANC33) at 250 m spatial resolution. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_water water Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) delta_time_end[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float64) attributes long_name: delta time end (Type is String) units: seconds since 2018-01-01 (Type is String) source: Derived (gps_seconds-gps_sec_offset) (Type is String) contentType: referenceInformation (Type is String) description: Time of the last photon contained within the data segment, in seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: delta_time latitude longitude (Type is String) segment_id_end[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int32) attributes long_name: end geolocation segment bin (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Geolocation segment number of the last photon in the land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) longitude_20m[ /gt2l/land_segments/delta_time= 0..22710] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: longitude of 20m segments (Type is String) units: degree (Type is String) source: ATBD Geosegment longitude (Type is String) valid_min: -180. (Type is Float32) valid_max: 180. (Type is Float32) contentType: modelResult (Type is String) description: Center longitude of 20m geosegments within each 100m land segment. (Type is String) coordinates: latitude longitude delta_time (Type is String) surf_type[ /gt2l/land_segments/delta_time= 0..22710] [ /ds_surf_type= 0..4] (Type is Int8) attributes long_name: surface type (Type is String) units: 1 (Type is String) source: ATL03 ATBD (Type is String) valid_min: 0 (Type is Int8) valid_max: 1 (Type is Int8) contentType: referenceInformation (Type is String) description: Flags describing which surface types this interval is associated with. 0=not type, 1=is type. Order of array is land, ocean, sea ice, land ice, inland water. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_type is_type (Type is String) flag_values: 0, 1 (Type is Int8) brightness_flag[ /gt2l/land_segments/delta_time= 0..22710] (Type is Byte) attributes long_name: brightness flag (Type is String) units: 1 (Type is String) source: Land ATBD Brightness_flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: Flag indicating that the ground surface is bright (e.g. snow-covered or other bright surfaces) (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_bright_surface bright_surface Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) segment_landcover[ /gt2l/land_segments/delta_time= 0..22710] (Type is Byte) attributes long_name: segment landcover (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_landcover (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: UN-FAO Land Cover Surface type classification as reference from Copernicus Land Cover(ANC18) at the 100m resolution. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: No_data Closed_forest_evergreen_needle_leaf Closed_forest_deciduous_needle_leaf Closed_forest_evergreen_broad_leaf Closed_forest_deciduous_broad_leaf Closed_forest_mixed Closed_forest_unknown Open_forest_evergreen_needle_leaf Open_forest_deciduous_needle_leaf Open_forest_evergreen_broad_leaf Open_forest_deciduous_broad_leaf Open_forest_mixed Open_forest_unknown Shrubs Herbaceous Herbaceous_wetleand Moss_and_lichen Bare_sparse_vegetation Cultivated_and_managed_vegetation_agriculture Urban_built_up Snow_and_ice Permanent_water_bodies Open_sea Undetermined (Type is String) flag_values: 0, 111, 113, 112, 114, 115, 116, 121, 123, 122, 124, 125, 126, 20, 30, 90, 100, 60, 40, 50, 70, 80, 200, 255 (Type is Byte) ph_removal_flag[ /gt2l/land_segments/delta_time= 0..22710] (Type is Byte) attributes long_name: ph removal flag (Type is String) units: 1 (Type is String) source: ATBD Final photon classification QA (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Flag indicating more than ph_removal_percent_limit (default 50.0) removed from land segment due to failing QA tests (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) asr[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: apparent surface reflectance (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: auxiliaryInformation (Type is String) description: Apparent surface reflectance (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_atlas_land[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas land (Type is String) units: 1 (Type is String) source: Land ATBD Refine Ground Estimates (Type is String) contentType: referenceInformation (Type is String) description: Total vertical geolocation error due to ranging and local surface slope. The parameter is computed for ATL08 as described in equation 1.2 ATL08 ATBD. (Type is String) coordinates: delta_time latitude longitude (Type is String) segment_id_beg[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int32) attributes long_name: begin geolocation segment bin (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Geolocation segment number of the first photon in the land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_along[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas x (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Total along-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_along. Sigma_atlas_x is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_h[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: dem height (Type is String) units: meters (Type is String) source: Arctic, Antarctic, Global, MSS DEM (Type is String) contentType: referenceInformation (Type is String) description: Best available DEM (in priority of Arctic/Antarctic/Global/MSS) value at the geolocation point. Height is in meters above the WGS84 Ellipsoid. (Type is String) coordinates: delta_time latitude longitude (Type is String) beam_coelev[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: beam co-elevation (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Co-elevation (CE) is direction from vertical of the laser beam as seen by an observer located at the laser ground spot. (Type is String) coordinates: delta_time latitude longitude (Type is String) sat_flag[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int8) attributes long_name: saturation flag (Type is String) units: 1 (Type is String) source: ATL03, Land ATBD Saturation Flag (Type is String) valid_min: -1 (Type is Int8) valid_max: 127 (Type is Int8) contentType: auxiliaryInformation (Type is String) description: Flag derived from full_sat_fract on the ATL03 data product, averaged over 5 geosegments in 100m land segment (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_saturation_detected saturation_detected not_enough_valid_data Undetermined (Type is String) flag_values: 0, 1, -1, 127 (Type is Int8) sigma_topo[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas topo (Type is String) units: 1 (Type is String) source: Land ATBD Refine Ground Estimates (Type is String) contentType: referenceInformation (Type is String) description: Total uncertainty that include sigma_h plus geolocation uncertainty due to local slope (equation 1.3). The local slope is multiplied by the geolocation uncertainty factor. This will be used to determine the total vertical geolocation error due to ranging and local slope. (Type is String) coordinates: delta_time latitude longitude (Type is String) night_flag[ /gt2l/land_segments/delta_time= 0..22710] (Type is Byte) attributes long_name: night flag (Type is String) units: 1 (Type is String) source: Land ATBD Night_Flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Flag indicating the data were acquired in night conditions: 0=day, 1=night. Flag is derived from solar elevation at the geolocated segment. IF solar elevation is above threshold it is day, if not then it is night. Threshold is set in atlas_l3a_const_mod. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: day night Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) delta_time_beg[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float64) attributes long_name: delta time begin (Type is String) units: seconds since 2018-01-01 (Type is String) source: Derived (gps_seconds-gps_sec_offset) (Type is String) contentType: referenceInformation (Type is String) description: Time of the first photon contained within the data segment, in seconds since the ATLAS SDP GPS Epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_h[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: height uncertainty (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m) provided at the geolocation segment rate on ATL03. Sigma_h is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) last_seg_extend[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes long_name: last segment extended (Type is String) standard_name: last_seg_extend (Type is String) units: kilometers (Type is String) source: Land ATBD Preparing ATL03 data for input (Type is String) contentType: auxiliaryInformation (Type is String) description: The distance (km) that the last ATL08 processing segment in a file is either extended or overlapped with the previous ATL08 processing segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) column_od_asr[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Column optical depth from ASR (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: auxiliaryInformation (Type is String) description: Optical depth of atmosphere column based on apparent surface reflectance and the assumed actual surface reflectance. (Type is String) coordinates: delta_time latitude longitude (Type is String) atlas_pa[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: atlas pointing angle (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Off nadir pointing angle (in radians) of the satellite to increase spatial sampling in the non-polar regions. ATLAS_PA =radians(90degs-beam_coelev). (Type is String) coordinates: delta_time latitude longitude (Type is String) ph_ndx_beg[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int64) attributes long_name: photon index begin (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Index (1-based) within the photon-rate data (/land_segments/photons) of the first photon within this each land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) solar_elevation[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes long_name: solar elevation (Type is String) units: degrees (Type is String) source: ATL03 ATBD (Type is String) contentType: referenceInformation (Type is String) description: Solar Angle above or below the plane tangent to the ellipsoid surface at the laser spot. Positive values mean the sun is above the horizon, while negative values mean it is below the horizon. The effect of atmospheric refraction is not included. This is a low precision value, with approximately TBD degree accuracy. (Type is String) coordinates: delta_time latitude longitude (Type is String) latitude_20m[ /gt2l/land_segments/delta_time= 0..22710] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: latitude of 20m segments (Type is String) units: degree (Type is String) source: ATBD Geosegment latitude (Type is String) valid_min: -90. (Type is Float32) valid_max: 90. (Type is Float32) contentType: modelResult (Type is String) description: Center latitude of 20m geosegments within each 100m land segment. (Type is String) coordinates: latitude longitude delta_time (Type is String) cloud_fold_flag[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int8) attributes long_name: cloud folding flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: modelResult (Type is String) description: Flag that indicates this profile likely contains cloud signal folded down from above 15 km to the last 2-3 km of the profile. See ATL09 ATBD Table 3.9 for detailed flag value meanings. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_folding goes5_indicates profile_indicates both_indicate outside_limits (Type is String) flag_values: 0, 1, 2, 3, 127 (Type is Int8) n_seg_ph[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int32) attributes long_name: number of photons (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of photons within each land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) terrain_flg[ /gt2l/land_segments/delta_time= 0..22710] (Type is Byte) attributes long_name: terrain flag (Type is String) units: 1 (Type is String) source: Land ATBD Segment_terrain flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Terrain flag quality check to indicate a deviation above a threshold from the reference DEM height reported on the product. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) urban_flag[ /gt2l/land_segments/delta_time= 0..22710] (Type is Byte) attributes long_name: segment urban flag (Type is String) units: 1 (Type is String) source: Land ATBD Urban_flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: The urban flag indicates that a segment is likely located over an urban area as determined by coincident pixels in the Global Urban Footprint (GUF) 0.4 arcsecond product. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_urban urban Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) permafrost_alt[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: permafrost active layer thickness (Type is String) standard_name: permafrost_alt (Type is String) units: meters (Type is String) source: ESA CCI, ANC47 (Type is String) valid_min: 0. (Type is Float32) valid_max: 100. (Type is Float32) contentType: referenceInformation (Type is String) description: Permafrost active layer thickness (m) from ESA CCI 2019 northern hemisphere permafrost dataset (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_removal_flag[ /gt2l/land_segments/delta_time= 0..22710] (Type is Byte) attributes long_name: dem removal flag (Type is String) units: 1 (Type is String) source: ATBD Segment reference DEM removal flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: Flag indicating more than dem_removal_percent_limit (default 20.0) removed from land segment due to failing DEM-QA tests (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) h_dif_ref[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: h dif from reference (Type is String) units: meters (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) contentType: modelResult (Type is String) description: Difference between h_te_median and ref_DEM (Type is String) coordinates: delta_time latitude longitude (Type is String) canopy(Type is Group) attributes description: Contains height parameters based on the land algorithm. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) h_canopy[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: height canopy (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: 98% height of all the individual canopy relative heights for the segment above the estimated terrain surface. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) canopy_rh_conf[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int8) attributes units: 1 (Type is String) long_name: canopy relative height confidence (Type is String) source: Land/Veg ATBD Vegetation Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 2 (Type is Int8) contentType: modelResult (Type is String) description: Canopy relative height confidence flag based on percentage of ground and canopy photons within a segment: 0 (<5% canopy), 1 (>5% canopy, <5% ground), 2 (>5% canopy, >5% ground). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: <5%_canopy >=5%_canopy_<5%_ground >=5%_canopy_>=5%_ground (Type is String) flag_values: 0, 1, 2 (Type is Int8) h_median_canopy_abs[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute segment median canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The median of individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_min_canopy[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: minimum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of relative individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_mean_canopy_abs[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute mean canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Mean of the individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_median_canopy[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: median canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The median of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. This parameter should be equivalent to RH50 reported in the literature. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_abs[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute segment canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The 98% height of all the absolute individual canopy heights referenced above the WGS84 ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) toc_roughness[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: top of canopy roughness (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Standard deviation of the relative heights of all photons classified as top of canopy within the segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_min_canopy_abs[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute minimum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of absolute individual canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_dif_canopy[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy diff to median height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Difference between h_canopy and h_median_canopy (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_quad[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy quadratic mean (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The quadratic mean height of individual classified relative canopy photon heights above the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_20m[ /gt2l/land_segments/delta_time= 0..22710] [ /ds_geosegments= 0..4] (Type is Float32) attributes units: m (Type is String) _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy height 20m (Type is String) source: ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Canopy height for each 20m geosegment with each 100m land segment. (Type is String) coordinates: ../latitude ../longitude ../delta_time (Type is String) n_ca_photons[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int32) attributes long_name: number canopy photons (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The number of photons classified as canopy within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_can[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Canopy photon rate (Type is String) units: s^-1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Calculated photon rate of canopy photons within each 100m segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) centroid_height[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: centroid height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Optical centroid of all photons classified as either canopy or ground points within the segment. The heights used in this calculation are absolute heights above the reference ellipsoid. This parameter is equivalent to the centroid height produced ICESat GLA14. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) canopy_h_metrics_abs[ /gt2l/land_segments/delta_time= 0..22710] [ /ds_metrics= 0..17] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy absolute height metrics (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Height metrics based on the cumulative distribution of absolute canopy heights above the WGS84 Ellipsoid. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) can_noise[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy noise rate (Type is String) units: count/meter (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Number of noise photons calculated that fall within the canopy height for each 100 m segment based on ATL03 background rate parameters. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_mean_canopy[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mean canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Mean of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) subset_can_flag[ /gt2l/land_segments/delta_time= 0..22710] [ /ds_geosegments= 0..4] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: subset canopy flag (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: -1 (Type is Int8) valid_max: 1 (Type is Int8) contentType: modelResult (Type is String) description: Quality flag indicating the canopy photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: no_photon_data_within_geosegment no_canopy_photons_within_geosegment canopy_photons_present_within_geosegment (Type is String) flag_values: -1, 0, 1 (Type is Int8) canopy_h_metrics[ /gt2l/land_segments/delta_time= 0..22710] [ /ds_metrics= 0..17] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy height metrics (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Height metrics based on the cumulative distribution of relative canopy heights above the interpolated ground surface. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) n_toc_photons[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int32) attributes long_name: number top of canopy photons (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The number of photons classified as top of canopy within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_max_canopy_abs[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute maximum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Maximum of individual absolute canopy heights within segment referenced above the WGS84 ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_uncertainty[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment canopy height uncertainty (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: qualityInformation (Type is String) description: Uncertainty of the relative canopy heights for the segment. Incorporates all systematic uncertainties as well as uncertainty from errors of identified photons. See section 1 and equations 1.4 and 1.5 of the ATL08 ATBD. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_can_nr[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: noise reduced number of canopy photons (Type is String) units: s^-1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Noise removed photon canopy rate within each 100 m segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) can_quality_score[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int8) attributes units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: modelResult (Type is String) description: Canopy quality score based on coincident conditions, from ATL08 ATBD section titled "Canopy Quality Score". (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) _FillValue: 127 (Type is Int8) long_name: canopy quality score (Type is String) canopy_openness[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy openness (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Standard Deviation of all photons classified as canopy photons within the segment to provide inference of canopy openness. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_max_canopy[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: maximum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Relative maximum of individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. Should be equivalent to RH100 metric reported in the literature. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) segment_cover[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int16) attributes _FillValue: 32767 (Type is Int16) long_name: canopy cover percentage (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Average percentage value of the valid (value <= 100) Copernicus fractional cover product for each 100 m segment. This data is temporally static, and is the summation of forest and shrub land cover fractions. Source data from: https://land.copernicus.eu/en/products/global-dynamic-land-cover/copernicus-global-land-service-land-cover-100m-collection-3-epoch-2019-globe . (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) terrain(Type is Group) attributes description: Contains terrain parameters at a 100m aggregation. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) h_te_uncertainty[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: uncertainty of h_te_mean (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Uncertainty of the mean terrain height for the segment. This uncertainty incorporates all systematic uncertainties(e.g. timing orbits, geolocation,etc.) as well as uncertainty from errors of identified photons. This parameter is described in section 1, equation 1.4 in ATL08 ATBD. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_mean[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mean terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The mean of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_min[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: minimum terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_te[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Terrain photon rate (Type is String) units: s^-1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Calculated photon rate of terrain photons within each 100m segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_interp[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: interpolated terrain surface height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Interpolated terrain surface height above the WGS84 Ellipsoid at the midpoint of the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_max[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: maximum terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The maximum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_rh25[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes units: meters (Type is String) _FillValue: 3.402823466e+38 (Type is Float32) long_name: Terrain height 25% percentile (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The terrain elevation from the 25% height. The classified ground photons are sorted into a cumulative distribution and the height associated with the 25% height for that segment is reported. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_skew[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: skew of terrain heights (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The skewness of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_best_fit_20m[ /gt2l/land_segments/delta_time= 0..22710] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: best fit 20m (Type is String) units: m (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Best fit terrain height to center of each 20m geosegment within each 100m land segment. (Type is String) coordinates: ../latitude ../longitude ../delta_time (Type is String) h_te_median[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: median terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The median of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_best_fit[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain height best fit (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The best fit terrain elevation at the the mid-point location of each 100m segment. The mid-segment terrain elevation is determined by selecting the best of three fits- linear, 3rd order and 4th order polynomials - to the terrain photons and interpolating the elevation at the mid-point location of the 100 m segment. For the linear fit, a slope correction and weighting is applied to each ground photon based on the distance to the slope height at the center of the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_std[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain roughness (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The standard deviation of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) terrain_slope[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain slope (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The along-track slope of terrain, within each segment;computed by a linear fit of terrain classified photons. Slope is in units of delta height over delta along track distance. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) subset_te_flag[ /gt2l/land_segments/delta_time= 0..22710] [ /ds_geosegments= 0..4] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: subset terrain flag (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: -1 (Type is Int8) valid_max: 1 (Type is Int8) contentType: modelResult (Type is String) description: Quality flag indicating the terrain photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: no_photon_data_within_geosegment no_terrain_photons_within_geosegment terrain_photons_present_within_geosegment (Type is String) flag_values: -1, 0, 1 (Type is Int8) n_te_photons[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int32) attributes long_name: number of ground photons (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The number of the photons classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_mode[ /gt2l/land_segments/delta_time= 0..22710] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mode of terrain heights (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The mode of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) te_quality_score[ /gt2l/land_segments/delta_time= 0..22710] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: terrain quality score (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: modelResult (Type is String) description: Quality score based on coincident conditions, from ATL08 ATBD section titled "Terrain Quality Score". (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) signal_photons(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) description: Contains parameters related to individual photons. (Type is String) data_rate: Data are stored at the signal-photon classification rate. (Type is String) Dimensions: [ /gt2l/signal_photons/delta_time = 0..4981549 ] delta_time[ /gt2l/signal_photons/delta_time= 0..4981549] (Type is Float64) attributes long_name: delta time (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: ATL03 (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) classed_pc_indx[ /gt2l/signal_photons/delta_time= 0..4981549] (Type is Int32) attributes units: 1 (Type is String) long_name: indicies of classed photons (Type is String) source: Retained from prior a_alt_science_ph packet (Type is String) contentType: referenceInformation (Type is String) description: Index (1-based) of the ATL08 classified signal photon from the start of the ATL03 geolocation segment specified on the ATL08 product at the photon rate in the corresponding parameter, ph_segment_id. This index traces back to specific photon within a 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group. (Type is String) coordinates: delta_time (Type is String) ph_h[ /gt2l/signal_photons/delta_time= 0..4981549] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: relative photon height (Type is String) standard_name: height (Type is String) units: meters (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: physicalMeasurement (Type is String) description: Height of photons above interpolated land surface (Type is String) coordinates: delta_time (Type is String) d_flag[ /gt2l/signal_photons/delta_time= 0..4981549] (Type is Int8) attributes long_name: dragann flag (Type is String) units: 1 (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: qualityInformation (Type is String) description: Flag indicating the labeling of DRAGANN noise filtering for a given photon. (Type is String) coordinates: delta_time (Type is String) flag_meanings: noise signal (Type is String) flag_values: 0, 1 (Type is Int8) classed_pc_flag[ /gt2l/signal_photons/delta_time= 0..4981549] (Type is Int8) attributes long_name: photon land atbd classification (Type is String) units: 1 (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: modelResult (Type is String) description: Land Vegetation ATBD classification flag for each photon as either noise, ground, canopy, and top of canopy. 0 = noise, 1 = ground, 2 = canopy, or 3 = top of canopy. (Type is String) coordinates: delta_time (Type is String) flag_meanings: noise ground canopy top_of_canopy (Type is String) flag_values: 0, 1, 2, 3 (Type is Int8) ph_segment_id[ /gt2l/signal_photons/delta_time= 0..4981549] (Type is Int32) attributes long_name: segment id of photon (Type is String) units: 1 (Type is String) source: Retained from prior a_alt_science_ph packet (Type is String) contentType: referenceInformation (Type is String) description: Segment ID of photons tracing back to specific 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the photon on ATL03 is the segment_id, orbit, and classed_pc_indx. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group. (Type is String) coordinates: delta_time (Type is String) ancillary_data(Type is Group) attributes data_rate: Data within this group pertain to the granule in its entirety. (Type is String) description: Contains information ancillary to the data product. This may include product characteristics, instrument characteristics and/or processing constants. (Type is String) release[ 0..0] (Type is String) attributes long_name: Release Number (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Release number of the granule. The release number is incremented when the software or ancillary data used to create the granule has been changed. (Type is String) end_geoseg[ 0..0] (Type is Int32) attributes long_name: Ending Geolocation Segment (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: The ending geolocation segment number associated with the data contained within this granule. ICESat granule geographic regions are further refined by geolocation segments. During the geolocation process, a geolocation segment is created approximately every 20m from the start of the orbit to the end. The geolocation segments help align the ATLAS strong a weak beams and provide a common segment length for the L2 and higher products. The geolocation segment indices differ slightly from orbit-to-orbit because of the irregular shape of the Earth. The geolocation segment indices on ATL01 and ATL02 are only approximate because beams have not been aligned at the time of their creation. (Type is String) version[ 0..0] (Type is String) attributes long_name: Version (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Version number of this granule within the release. It is a sequential number corresponding to the number of times the granule has been reprocessed for the current release. (Type is String) end_region[ 0..0] (Type is Int32) attributes long_name: Ending Region (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: The ending product-specific region number associated with the data contained within this granule. ICESat-2 data products are separated by geographic regions. The data contained within a specific region are the same for ATL01 and ATL02. ATL03 regions differ slightly because of different geolocation segment locations caused by the irregular shape of the Earth. The region indices for other products are completely independent. (Type is String) atlas_sdp_gps_epoch[ 0..0] (Type is Float64) attributes long_name: ATLAS Epoch Offset (Type is String) units: seconds since 1980-01-06T00:00:00.000000Z (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS Standard Data Product (SDP) epoch (2018-01-01:T00.00.00.000000 UTC). Add this value to delta time parameters to compute full gps_seconds (relative to the GPS epoch) for each data point. (Type is String) end_rgt[ 0..0] (Type is Int32) attributes long_name: Ending Reference Groundtrack (Type is String) units: 1 (Type is String) source: Derived (Type is String) valid_min: 1 (Type is Int32) valid_max: 1387 (Type is Int32) contentType: auxiliaryInformation (Type is String) description: The ending reference groundtrack (RGT) number associated with the data contained within this granule. There are 1387 reference groundtrack in the ICESat-2 repeat orbit. The reference groundtrack increments each time the spacecraft completes a full orbit of the Earth and resets to 1 each time the spacecraft completes a full cycle. (Type is String) end_delta_time[ 0..0] (Type is Float64) attributes long_name: ATLAS End Time (Actual) (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of GPS seconds since the ATLAS SDP epoch at the last data point in the file. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) end_orbit[ 0..0] (Type is Int32) attributes long_name: Ending Orbit Number (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: The ending orbit number associated with the data contained within this granule. The orbit number increments each time the spacecraft completes a full orbit of the Earth. (Type is String) start_cycle[ 0..0] (Type is Int32) attributes long_name: Starting Cycle (Type is String) units: 1 (Type is String) source: Derived (Type is String) valid_min: 0 (Type is Int32) valid_max: 99 (Type is Int32) contentType: auxiliaryInformation (Type is String) description: The starting cycle number associated with the data contained within this granule. The cycle number is the counter of the number of 91-day repeat cycles completed by the mission. (Type is String) data_end_utc[ 0..0] (Type is String) attributes long_name: End UTC Time of Granule (CCSDS-A, Actual) (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: UTC (in CCSDS-A format) of the last data point within the granule. (Type is String) control[ 0..0] (Type is String) attributes long_name: Control File (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: PGE-specific control file used to generate this granule. To re-use, replace breaks (BR) with linefeeds. (Type is String) start_gpssow[ 0..0] (Type is Float64) attributes long_name: Start GPS SOW of Granule (Actual) (Type is String) units: seconds (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: GPS seconds-of-week of the first data point in the granule. (Type is String) granule_end_utc[ 0..0] (Type is String) attributes long_name: End UTC Time of Granule (CCSDS-A, Requested) (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Requested end time (in UTC CCSDS-A) of this granule. (Type is String) end_cycle[ 0..0] (Type is Int32) attributes long_name: Ending Cycle (Type is String) units: 1 (Type is String) source: Derived (Type is String) valid_min: 0 (Type is Int32) valid_max: 99 (Type is Int32) contentType: auxiliaryInformation (Type is String) description: The ending cycle number associated with the data contained within this granule. The cycle number is the counter of the number of 91-day repeat cycles completed by the mission. (Type is String) granule_start_utc[ 0..0] (Type is String) attributes long_name: Start UTC Time of Granule (CCSDS-A, Requested) (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Requested start time (in UTC CCSDS-A) of this granule. (Type is String) start_delta_time[ 0..0] (Type is Float64) attributes long_name: ATLAS Start Time (Actual) (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of GPS seconds since the ATLAS SDP epoch at the first data point in the file. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) start_geoseg[ 0..0] (Type is Int32) attributes long_name: Starting Geolocation Segment (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: The starting geolocation segment number associated with the data contained within this granule. ICESat granule geographic regions are further refined by geolocation segments. During the geolocation process, a geolocation segment is created approximately every 20m from the start of the orbit to the end. The geolocation segments help align the ATLAS strong a weak beams and provide a common segment length for the L2 and higher products. The geolocation segment indices differ slightly from orbit-to-orbit because of the irregular shape of the Earth. The geolocation segment indices on ATL01 and ATL02 are only approximate because beams have not been aligned at the time of their creation. (Type is String) start_orbit[ 0..0] (Type is Int32) attributes long_name: Starting Orbit Number (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: The starting orbit number associated with the data contained within this granule. The orbit number increments each time the spacecraft completes a full orbit of the Earth. (Type is String) data_start_utc[ 0..0] (Type is String) attributes long_name: Start UTC Time of Granule (CCSDS-A, Actual) (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: UTC (in CCSDS-A format) of the first data point within the granule. (Type is String) end_gpsweek[ 0..0] (Type is Int32) attributes long_name: Ending GPSWeek of Granule (Actual) (Type is String) contentType: auxiliaryInformation (Type is String) description: GPS week number of the last data point in the granule. (Type is String) units: weeks from 1980-01-06 (Type is String) source: Derived (Type is String) start_rgt[ 0..0] (Type is Int32) attributes long_name: Starting Reference Groundtrack (Type is String) units: 1 (Type is String) source: Derived (Type is String) valid_min: 1 (Type is Int32) valid_max: 1387 (Type is Int32) contentType: auxiliaryInformation (Type is String) description: The starting reference groundtrack (RGT) number associated with the data contained within this granule. There are 1387 reference groundtrack in the ICESat-2 repeat orbit. The reference groundtrack increments each time the spacecraft completes a full orbit of the Earth and resets to 1 each time the spacecraft completes a full cycle. (Type is String) end_gpssow[ 0..0] (Type is Float64) attributes long_name: Ending GPS SOW of Granule (Actual) (Type is String) units: seconds (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: GPS seconds-of-week of the last data point in the granule. (Type is String) qa_at_interval[ 0..0] (Type is Float64) attributes long_name: QA Along-Track Interval (Type is String) units: 1 (Type is String) source: control (Type is String) contentType: auxiliaryInformation (Type is String) description: Statistics time interval for along-track QA data. (Type is String) start_region[ 0..0] (Type is Int32) attributes long_name: Starting Region (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: The starting product-specific region number associated with the data contained within this granule. ICESat-2 data products are separated by geographic regions. The data contained within a specific region are the same for ATL01 and ATL02. ATL03 regions differ slightly because of different geolocation segment locations caused by the irregular shape of the Earth. The region indices for other products are completely independent. (Type is String) start_gpsweek[ 0..0] (Type is Int32) attributes long_name: Start GPSWeek of Granule (Actual) (Type is String) units: weeks from 1980-01-06 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: GPS week number of the first data point in the granule. (Type is String) land(Type is Group) attributes description: Constants used in the land_vegetation ATBD (Type is String) stat20m_thresh[ 0..0] (Type is Int32) attributes long_name: Threshold for geosegment statistics (Type is String) units: 1 (Type is String) source: ATBD canopy_height GeoSegment (Type is String) contentType: auxiliaryInformation (Type is String) description: Minimum number of photons to compute statistics upon. (Default =10) (Type is String) ca_class[ 0..0] (Type is Int32) attributes long_name: Canopy class value (Type is String) units: 1 (Type is String) source: ATBD "Classifying the Photons" (Type is String) contentType: auxiliaryInformation (Type is String) description: Canopy classification flag value. (Default = 2) (Type is String) skill_solarang_can_penalty_2[ 0..0] (Type is Int32) attributes long_name: Second canopy score demerit value for solar angle (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Second canopy quality score demerit for solar elevation angle. (Default =10) (Type is String) canopy_flag_switch[ 0..0] (Type is Int32) attributes long_name: canopy_flag switch (Type is String) units: 1 (Type is String) source: ATBD Find top of canopy (Type is String) contentType: auxiliaryInformation (Type is String) description: Controls entrance to the canopy flag subroutine . (Default = 1) (Type is String) skill_cldfold_can_penalty[ 0..0] (Type is Int32) attributes long_name: Canopy score demerit value for cloud fold flag (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Canopy quality score demerit for cloud fold flag. (Default =10) (Type is String) skill_demremov_can_penalty[ 0..0] (Type is Int32) attributes long_name: Canopy score demerit value for DEM removal flag (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Canopy quality score demerit for DEM removal flag. (Default =10) (Type is String) skill_solarang_thrsh_te_1[ 0..0] (Type is Float32) attributes long_name: First threshold for solar angle terrain score demerit (Type is String) units: degrees (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: First threshold of solar elevation angle for terrain quality score demerit. (Default =10.0) (Type is String) skill_mswflag_can_penalty[ 0..0] (Type is Int32) attributes long_name: Canopy score demerit value for MSW flag (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Canopy quality score demerit for MSW flag. (Default =10) (Type is String) up_toc_bnd[ 0..0] (Type is Float32) attributes long_name: Upper bound restricting the search of a top of canopy surface. (Type is String) units: meters (Type is String) source: ATBD Find the top of canopy (Type is String) contentType: auxiliaryInformation (Type is String) description: Upper bound restricting the search of a top of canopy surface. (Default=1.0) (Type is String) skill_radmtry_thrsh_te_1[ 0..0] (Type is Float32) attributes long_name: First threshold for radiometry terrain score demerit (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: First threshold of radiometry for terrain quality score demerit. (Default =0.2) (Type is String) fnlgnd_filter_switch[ 0..0] (Type is Int32) attributes long_name: finalground filter switch (Type is String) units: 1 (Type is String) source: ATBD "photon classification QA check" (Type is String) contentType: auxiliaryInformation (Type is String) description: Controls filtering based on FINALGROUND. (Default = 1) (Type is String) skill_demremov_te_penalty[ 0..0] (Type is Int32) attributes long_name: Terrain score demerit value for DEM removal flag (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Terrain quality score demerit for DEM removal flag. (Default =10) (Type is String) psf[ 0..0] (Type is Float32) attributes long_name: Point Spread Function (Type is String) units: meters (Type is String) source: ATBD Refine ground estimates (Type is String) contentType: auxiliaryInformation (Type is String) description: Parameter controlling identification of photons around an interpolated surface. (Default = 0.5) (Type is String) dem_removal_percent_limit[ 0..0] (Type is Float32) attributes long_name: dem_removal_flag set threshold (Type is String) units: percent (Type is String) source: ATBD "segment_reference_DEM_removal_flag" (Type is String) contentType: auxiliaryInformation (Type is String) description: Percent of photons in land segment failing DEM test to set dem_removal_flag. (default = 20.0) (Type is String) atl08_region[ 0..1] (Type is Int32) attributes long_name: atl08 region (Type is String) standard_name: atl08_region (Type is String) units: 1 (Type is String) source: Land ATBD reference summary table (Type is String) contentType: modelResult (Type is String) description: ATL08 region(s) encompassed by ATL03 granule being processed (Type is String) can_noise_thresh[ 0..0] (Type is Int32) attributes long_name: Threshold for reclassification of canopy as noise (Type is String) source: ATBD "Canopy Photon Filtering" (Type is String) contentType: auxiliaryInformation (Type is String) description: Threshold, as a number of canopy photons in the CAN_FILT_SEG, used for the reclassification of canopy signal photons. (Default = 75) (Type is String) units: 1 (Type is String) skill_radmtry_thrsh_te_2[ 0..0] (Type is Float32) attributes long_name: Second threshold for radiometry terrain score demerit (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Second threshold of radiometry for terrain quality score demerit. (Default =0.5) (Type is String) relief_hbot[ 0..0] (Type is Float32) attributes long_name: lower relief percentile (Type is String) units: meters (Type is String) source: ATBD De-trend Data (Type is String) contentType: auxiliaryInformation (Type is String) description: The approximate relief of the L-km segment uses the percentile height values, relief_htop and relief_hbot. (Default=0.05) (Type is String) dem_filter_switch[ 0..0] (Type is Int32) attributes long_name: dem_filter switch (Type is String) units: 1 (Type is String) source: ATBD De-trend Data (Type is String) contentType: auxiliaryInformation (Type is String) description: Controls filtering based on DEM. (Default = 1) (Type is String) relief_htop[ 0..0] (Type is Float32) attributes long_name: Upper relief percentile (Type is String) units: meters (Type is String) source: ATBD De-trend Data (Type is String) contentType: auxiliaryInformation (Type is String) description: The approximate relief of the L-km segment uses the percentile height values, relief_htop and relief_hbot. (Default=0.95) (Type is String) dseg_buf[ 0..0] (Type is Int32) attributes long_name: DRAGANN segment buffer size (Type is String) units: 1 (Type is String) source: ATBD "Noise filtering via DRAGANN" (Type is String) contentType: auxiliaryInformation (Type is String) description: DRAGANN segment buffer length in 20m geolocated segments along ground track. (Default=10) (Type is String) night_thresh[ 0..0] (Type is Float32) attributes long_name: Threshold for night (Type is String) units: 1 (Type is String) source: ATBD Night_flag (Type is String) contentType: auxiliaryInformation (Type is String) description: Solar elevation threshold for determining night time conditions. (Default =0.0) (Type is String) h_canopy_perc[ 0..0] (Type is Float32) attributes long_name: h_canopy percentile (Type is String) units: 1 (Type is String) source: ATBD segment parameters for Canopy Products (Type is String) contentType: auxiliaryInformation (Type is String) description: Percentile component of h_canopy parameter. (Default =0.95) (Type is String) up_filt_bnd[ 0..0] (Type is Int32) attributes long_name: Proportionality coefficient for controlling the bounds of the filter window size as a function of number of signal photons. (Type is String) units: 1 (Type is String) source: ATBD initial ground estimate (Type is String) contentType: auxiliaryInformation (Type is String) description: Lower bound of the filter window size function. (Default = 46) (Type is String) lw_filt_bnd[ 0..0] (Type is Int32) attributes long_name: Proportionality coefficient for controlling the bounds of the filter window size as a function of number of signal photons. (Type is String) units: 1 (Type is String) source: ATBD initial ground estimate (Type is String) contentType: auxiliaryInformation (Type is String) description: Lower bound of the filter window size function. (Default = 5) (Type is String) canopy20m_thresh[ 0..0] (Type is Int32) attributes long_name: Threshold for geosegment canopy (Type is String) units: 1 (Type is String) source: ATBD "canopy_height GeoSegment" (Type is String) contentType: auxiliaryInformation (Type is String) description: Minimum number of photons to compute statistics upon. (Default =3) (Type is String) skill_demremov_can_thrsh[ 0..0] (Type is Int32) attributes long_name: Threshold for DEM removal flag canopy score demerit (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Threshold of DEM removal flag for canopy quality score demerit. (Default =1) (Type is String) skill_mswflag_te_penalty[ 0..0] (Type is Int32) attributes long_name: Terrain score demerit value for MSW flag (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Terrain quality score demerit for MSW flag. (Default =10) (Type is String) skill_od_thrsh_can_2[ 0..0] (Type is Float32) attributes long_name: Second threshold for optical depth canopy score demerit (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Second threshold of optical depth for canopy quality score demerit. (Default =0.3) (Type is String) ph_removal_percent_limit[ 0..0] (Type is Float32) attributes long_name: ph_removal_flag set threshold (Type is String) units: percent (Type is String) source: ATBD Final photon classification QA (Type is String) contentType: auxiliaryInformation (Type is String) description: Percent of photons in land segment removed to set ph_removal_flag. (default = 50.0) (Type is String) canopy_seg[ 0..0] (Type is Int32) attributes long_name: segment size in canopy filter (Type is String) units: 1 (Type is String) source: ATBD segment parameters for canopy products (Type is String) contentType: auxiliaryInformation (Type is String) description: Segment in number of signal photons for filtering sparse canopy cover. (Default = 500) (Type is String) max_try[ 0..0] (Type is Int32) attributes long_name: Maximum try count (Type is String) units: 1 (Type is String) source: ATBD "dynamically determing a DRAGANN parameter" (Type is String) contentType: auxiliaryInformation (Type is String) description: Maximum number of tries to compute a P value in alternative DRAGANN (Type is String) skill_radmtry_te_penalty_1[ 0..0] (Type is Int32) attributes long_name: First terrain score demerit value for radiometry (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: First terrain quality score demerit for radiometry. (Default =5) (Type is String) bin_size_n[ 0..0] (Type is Int32) attributes long_name: neighbor histogram bin size (Type is String) units: 1 (Type is String) source: ATBD "Noise filtering via DRAGANN" (Type is String) contentType: auxiliaryInformation (Type is String) description: Size of neighbor histogram bins in number of neighbors in DRAGANN. (Default = 1) (Type is String) skill_od_can_penalty_2[ 0..0] (Type is Int32) attributes long_name: Second canopy score demerit value for optical depth (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Second canopy quality score demerit for optical depth. (Default =10) (Type is String) lw_gnd_bnd[ 0..0] (Type is Float32) attributes long_name: Lower bound restricting the search of a ground surface in canopy cases. (Type is String) units: meters (Type is String) source: ATBD initial ground estimate (Type is String) contentType: auxiliaryInformation (Type is String) description: Lower bound restricting the search of a ground surface in canopy cases. (Default = -4.0) (Type is String) del_mu[ 0..0] (Type is Float32) attributes long_name: Step size for optimizing the mean parameter of Gaussian function. (Type is String) units: 1 (Type is String) source: ATBD "Noise filtering via DRAGANN" (Type is String) contentType: auxiliaryInformation (Type is String) description: Step size for optimizing the mean parameter of Gaussian function. (Default = 0.2) (Type is String) skill_telemratio_can_thrsh[ 0..0] (Type is Float32) attributes long_name: Threshold for telemetry band ratio canopy score demerit (Type is String) units: 1 (Type is String) source: ATBD Terrain Canopy Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Threshold of telemetry band ratio for canopy quality score demerit. (Default =0.4) (Type is String) yapc_switch[ 0..0] (Type is Int32) attributes long_name: YAPC switch (Type is String) units: 1 (Type is String) source: ATBD De-trend Data (Type is String) contentType: auxiliaryInformation (Type is String) description: Controls inclusion of YAPC analysis for ground finding subroutines. (Default =1) (Type is String) lw_toc_cut[ 0..0] (Type is Float32) attributes long_name: Lower cutoff for top of canopy (Type is String) units: meters (Type is String) source: ATBD Find the top of canopy (Type is String) contentType: auxiliaryInformation (Type is String) description: Lower cutoff for top of canopy surface. (Default = 2.0) (Type is String) class_thresh[ 0..0] (Type is Int32) attributes long_name: Threshold flag value for classification of photons as signal via input from ATL03 (Type is String) units: 1 (Type is String) source: ATBD section "De-trend Data" (Type is String) contentType: auxiliaryInformation (Type is String) description: Threshold flag value for classification of photons as signal via input from ATL03. (Default =3) (Type is String) skill_od_te_penalty_1[ 0..0] (Type is Int32) attributes long_name: First terrain score demerit value for optical depth (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: First terrain quality score demerit for optical depth. (Default =5) (Type is String) skill_od_can_penalty_1[ 0..0] (Type is Int32) attributes long_name: First canopy score demerit value for optical depth (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: First canopy quality score demerit for optical depth. (Default =5) (Type is String) lseg_buf[ 0..0] (Type is Int32) attributes long_name: Long segment buffer size (Type is String) units: 1 (Type is String) source: ATBD Preparing ATL03 data (Type is String) contentType: auxiliaryInformation (Type is String) description: Overlapping long segment buffer size in 20m geosegments along ground track. (Default=10) (Type is String) lw_toc_bnd[ 0..0] (Type is Float32) attributes long_name: Lower bound restricting the search of a top of canopy surface. (Type is String) units: meters (Type is String) source: ATBD Find the top of canopy (Type is String) contentType: auxiliaryInformation (Type is String) description: Lower bound restricting the search of a top of canopy surface. (Default = -4.0) (Type is String) up_toc_cut[ 0..0] (Type is Float32) attributes long_name: upper cutoff of top of canopy surface. (Type is String) units: meters (Type is String) source: ATBD Find the top of canopy (Type is String) contentType: auxiliaryInformation (Type is String) description: Upper cutoff for top of canopy surface. (Default = 150.0) (Type is String) gnd_stat_thresh[ 0..0] (Type is Float32) attributes long_name: Threshold for terrain statistics (Type is String) units: 1 (Type is String) source: ATBD segment parameters for Land Products (Type is String) contentType: auxiliaryInformation (Type is String) description: Minimum percentage of terrain photons to compute statistics upon. (Default =0.05) (Type is String) iter_max[ 0..0] (Type is Int32) attributes long_name: Maximum number of iterations for optimizing the Gaussian parameters for fitting of histogram. (Type is String) units: 1 (Type is String) source: ATBD "Noise filtering via DRAGANN" (Type is String) contentType: auxiliaryInformation (Type is String) description: Maximum number of iterations for optimizing the Gaussian parameters for fitting of histogram. (Default = 10) (Type is String) skill_cldfold_te_penalty[ 0..0] (Type is Int32) attributes long_name: Terrain score demerit value for cloud fold flag (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Terrain quality score demerit for cloud fold flag. (Default =10) (Type is String) skill_mswflag_te_thrsh[ 0..0] (Type is Int32) attributes long_name: Threshold for MSW flag terrain score demerit (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Threshold of MSW flag for terrain quality score demerit. (Default =1) (Type is String) skill_cldfold_can_thrsh[ 0..0] (Type is Int32) attributes long_name: Threshold for cloud fold flag canopy score demerit (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Threshold of cloud fold flag for canopy quality score demerit. (Default =1) (Type is String) gthresh_factor[ 0..0] (Type is Float32) attributes long_name: threshold for Gaussian Elimination (Type is String) units: 1 (Type is String) source: ATBD "Noise filtering via DRAGANN" (Type is String) contentType: auxiliaryInformation (Type is String) description: Controls threshold for Gaussian Elimination. (Default = 0.1) (Type is String) skill_demremov_te_thrsh[ 0..0] (Type is Int32) attributes long_name: Threshold for DEM removal flag terrain score demerit (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Threshold of DEM removal flag for terrain quality score demerit. (Default =1) (Type is String) skill_solarang_te_penalty_2[ 0..0] (Type is Int32) attributes long_name: Second terrain score demerit value for solar angle (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Second terrain quality score demerit for solar elevation angle. (Default =10) (Type is String) skill_telemratio_te_thrsh[ 0..0] (Type is Float32) attributes long_name: Threshold for telemetry band ratio terrain score demerit (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Threshold of telemetry band ratio for terrain quality score demerit. (Default =0.4) (Type is String) bright_thresh[ 0..0] (Type is Float32) attributes long_name: brightness flag average ph per shot (Type is String) source: ATBD "Brightness flag" (Type is String) contentType: auxiliaryInformation (Type is String) description: Threshold to set brightness_flag, average ground photons per shot. (Default = 3.0) (Type is String) units: 1 (Type is String) dseg[ 0..0] (Type is Int32) attributes long_name: DRAGANN segment size (Type is String) units: 1 (Type is String) source: ATBD "Noise filtering via DRAGANN" (Type is String) contentType: auxiliaryInformation (Type is String) description: DRAGANN segment length in 20m geolocated segments along ground track. (Default=170) (Type is String) skill_solarang_can_penalty_1[ 0..0] (Type is Int32) attributes long_name: First canopy score demerit value for solar angle (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: First canopy quality score demerit for solar elevation angle. (Default =5) (Type is String) bin_size_h[ 0..0] (Type is Float32) attributes long_name: neighbor histogram bin size (Type is String) units: 1 (Type is String) source: ATBD "Noise filtering via DRAGANN" (Type is String) contentType: auxiliaryInformation (Type is String) description: Histogram bin size for the alternative DRAGANN algorithm. (Default = 1.0) (Type is String) up_gnd_bnd[ 0..0] (Type is Float32) attributes long_name: Upper bound restricting the search of a ground surface in canopy cases. (Type is String) units: meters (Type is String) source: ATBD initial ground estimate (Type is String) contentType: auxiliaryInformation (Type is String) description: Upper bound restricting the search of a ground surface in canopy cases. (Default = 1.0) (Type is String) skill_solarang_thrsh_can_2[ 0..0] (Type is Float32) attributes long_name: Second threshold for solar angle canopy score demerit (Type is String) units: degrees (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Second threshold of solar elevation angle for canopy quality score demerit. (Default =20.0) (Type is String) min_nphs[ 0..0] (Type is Int32) attributes long_name: Minimum input photons (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Minimum number of input photons from ATL03 to process. (default=1) (Type is String) tc_thresh[ 0..0] (Type is Float32) attributes long_name: Canopy Flag threshold (Type is String) units: 1 (Type is String) source: ATBD Segment parameters for canopy products (Type is String) contentType: auxiliaryInformation (Type is String) description: Percentage threshold for average L-km segment tree cover to be considered canopy. (Default = 5.0) (Type is String) skill_solarang_te_penalty_1[ 0..0] (Type is Int32) attributes long_name: First terrain score demerit value for solar angle (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: First terrain quality score demerit for solar elevation angle. (Default =5) (Type is String) te_class[ 0..0] (Type is Int32) attributes long_name: Terrain class value (Type is String) units: 1 (Type is String) source: ATBD "Classifying the Photons" (Type is String) contentType: auxiliaryInformation (Type is String) description: Terrain classification flag value. (Default = 1) (Type is String) toc_class[ 0..0] (Type is Int32) attributes long_name: Top of canopy class value (Type is String) units: 1 (Type is String) source: ATBD "Classifying the Photons" (Type is String) contentType: auxiliaryInformation (Type is String) description: Top of canopy classification flag value. (Default = 3) (Type is String) iter_gnd[ 0..0] (Type is Int32) attributes long_name: Iterations of smoothing of interpolated ground surface for ground estimate. (Type is String) units: 1 (Type is String) source: ATBD Refine Ground Estimates (Type is String) contentType: auxiliaryInformation (Type is String) description: Iterations of smoothing of interpolated ground surface for refinement. (Default = 10) (Type is String) max_atl03files[ 0..0] (Type is Int32) attributes long_name: Maximum number of input ATL03s (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Maximum number of input ATL03 files. (Default = 200) (Type is String) noise_class[ 0..0] (Type is Int32) attributes long_name: Noise class value (Type is String) units: 1 (Type is String) source: ATBD "Classifying the Photons" (Type is String) contentType: auxiliaryInformation (Type is String) description: Noise classification flag value. (Default = 0) (Type is String) skill_od_thrsh_can_1[ 0..0] (Type is Float32) attributes long_name: First threshold for optical depth canopy score demerit (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: First threshold of optical depth for canopy quality score demerit. (Default =0.2) (Type is String) units: 1 (Type is String) terrain20m_thresh[ 0..0] (Type is Int32) attributes long_name: Threshold for geosegment terrain (Type is String) units: 1 (Type is String) source: ATBD Terrain Best Fit GeoSegment (Type is String) contentType: auxiliaryInformation (Type is String) description: Minimum number of photons to compute statistics upon. (Default =3) (Type is String) skill_cldfold_te_thrsh[ 0..0] (Type is Int32) attributes long_name: Threshold for cloud fold flag terrain score demerit (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Threshold of cloud fold flag for terrain quality score demerit. (Default =1) (Type is String) skill_snr_can_thrsh[ 0..0] (Type is Float32) attributes long_name: Threshold for signal-to-noise canopy score demerit (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Threshold of signal-to-noise for canopy quality score demerit. (Default =0.5) (Type is String) outlier_filter_switch[ 0..0] (Type is Int32) attributes long_name: outlier_filter switch (Type is String) units: 1 (Type is String) source: ATBD Filter outlier noise (Type is String) contentType: auxiliaryInformation (Type is String) description: Controls entrance to the outlier filter subroutine. (Default = 1) (Type is String) dragann_switch[ 0..0] (Type is Int32) attributes long_name: DRAGANN switch (Type is String) units: 1 (Type is String) source: ATBD "Noise filtering via DRAGANN" (Type is String) contentType: auxiliaryInformation (Type is String) description: Controls entrance to the DRAGANN subroutine. (Default =1) (Type is String) skill_telemratio_can_penalty[ 0..0] (Type is Int32) attributes long_name: Canopy score demerit value for telemetry band ratio (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Canopy quality score demerit for telemetry band ratio. (Default =10) (Type is String) units: 1 (Type is String) proc_geoseg[ 0..0] (Type is Int32) attributes long_name: Geosegment process interval length (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Geosegment process interval length. This controls the amount read from ATL03 and ATL09 at a time. (Default = 500000). (Type is String) skill_solarang_thrsh_can_1[ 0..0] (Type is Float32) attributes long_name: First threshold for solar angle canopy score demerit (Type is String) units: degrees (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: First threshold of solar elevation angle for canopy quality score demerit. (Default =10.0) (Type is String) can_stat_thresh[ 0..0] (Type is Float32) attributes long_name: Threshold for canopy statistics (Type is String) units: 1 (Type is String) source: ATBD segment parameters for canopy products (Type is String) contentType: auxiliaryInformation (Type is String) description: Minimum percentage of canopy photons to compute statistics upon. (Default =0.05) (Type is String) lseg[ 0..0] (Type is Int32) attributes long_name: Long segment size (Type is String) units: 1 (Type is String) source: ATBD Preparing ATL03 data (Type is String) contentType: auxiliaryInformation (Type is String) description: Long segment size in number of 20 meter segments along ground track. (Default=500) (Type is String) max_atl09files[ 0..0] (Type is Int32) attributes long_name: Maximum number of input ATL09s (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Maximum number of input ATL09 files. (Default = 200) (Type is String) skill_radmtry_thrsh_total_2[ 0..0] (Type is Float32) attributes long_name: Second threshold for total radiometry score demerit (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Second threshold of total radiometry for canopy quality score demerit. (Default =1.0) (Type is String) skill_od_thrsh_te_1[ 0..0] (Type is Float32) attributes long_name: First threshold for optical depth terrain score demerit (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: First threshold of optical depth for terrain quality score demerit. (Default =0.2) (Type is String) skill_radmtry_te_penalty_2[ 0..0] (Type is Int32) attributes long_name: Second terrain score demerit value for radiometry (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Second terrain quality score demerit for radiometry. (Default =10) (Type is String) skill_solarang_thrsh_te_2[ 0..0] (Type is Float32) attributes long_name: Second threshold for solar angle terrain score demerit (Type is String) units: degrees (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Second threshold of solar elevation angle for terrain quality score demerit. (Default =20.0) (Type is String) skill_snr_te_penalty[ 0..0] (Type is Int32) attributes long_name: Terrain score demerit value for signal-to-noise (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Terrain quality score demerit for signal-to-noise. (Default =10) (Type is String) ref_dem_limit[ 0..0] (Type is Float32) attributes long_name: DEM threshold (Type is String) units: meters (Type is String) source: ATBD De-trend Data (Type is String) contentType: auxiliaryInformation (Type is String) description: Reference DEM limit used to reclassify signal as noise. (default = 120.0) (Type is String) skill_telemratio_te_penalty[ 0..0] (Type is Int32) attributes long_name: Terrain score demerit value for telemetry band ratio (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Terrain quality score demerit for telemetry band ratio. (Default =10) (Type is String) skill_od_te_penalty_2[ 0..0] (Type is Int32) attributes long_name: Second terrain score demerit value for optical depth (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Second terrain quality score demerit for optical depth. (Default =10) (Type is String) skill_snr_can_penalty[ 0..0] (Type is Int32) attributes long_name: Canopy score demerit value for signal-to-noise (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Canopy quality score demerit for signal-to-noise ratio. (Default =10) (Type is String) max_peaks[ 0..0] (Type is Int32) attributes long_name: Maximum number of Gaussian peaks to fit in the data set (Type is String) units: 1 (Type is String) source: ATBD "Noise filtering via DRAGANN" (Type is String) contentType: auxiliaryInformation (Type is String) description: Maximum number of Gaussian peaks to fit in the data set in DRAGANN. (Default =10) (Type is String) skill_weakbeam_te_penalty[ 0..0] (Type is Int32) attributes long_name: Terrain score demerit value for weak beam (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Terrain quality score demerit for weak beam. (Default =5) (Type is String) skill_snr_te_thrsh[ 0..0] (Type is Float32) attributes long_name: Threshold for signal-to-noise terrain score demerit (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Threshold of signal-to-noise for terrain quality score demerit. (Default =0.5) (Type is String) stat_thresh[ 0..0] (Type is Int32) attributes long_name: Threshold for land statistics (Type is String) units: 1 (Type is String) source: ATBD Segment parameters for land products (Type is String) contentType: auxiliaryInformation (Type is String) description: Minimum number of photons to compute statistics upon. (Default =50) (Type is String) skill_radmtry_total_penalty_1[ 0..0] (Type is Int32) attributes long_name: First canopy score demerit value for total radiometry (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: First canopy quality score demerit for total radiometry. (Default =5) (Type is String) sig_rsq_search[ 0..0] (Type is Float32) attributes long_name: Square Radius of filter for canopy (Type is String) units: meters^2 (Type is String) source: ATBD Find the top of canopy (Type is String) contentType: auxiliaryInformation (Type is String) description: Top of canopy refinement square search radius. (Default = 10000.0) (Type is String) skill_weakbeam_can_penalty[ 0..0] (Type is Int32) attributes long_name: Canopy score demerit value for weak beam (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Canopy quality score demerit for weak beam. (Default =10) (Type is String) skill_radmtry_thrsh_total_1[ 0..0] (Type is Float32) attributes long_name: First threshold for total radiometry score demerit (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: First threshold of total radiometry for canopy quality score demerit. (Default =0.7) (Type is String) del_amp[ 0..0] (Type is Float32) attributes long_name: Step Gaussian Amplitude optimization (Type is String) units: 1 (Type is String) source: ATBD "Noise filtering via DRAGANN" (Type is String) contentType: auxiliaryInformation (Type is String) description: Step size for optimizing the amplitude variable of Gaussian function. (Default = 1.0) (Type is String) sseg[ 0..0] (Type is Float32) attributes long_name: Short Segment Length (Type is String) units: meters (Type is String) source: ATBD segment parameters for Land Products (Type is String) contentType: auxiliaryInformation (Type is String) description: Short segment length in meters. (Default = 100.0) (Type is String) skill_od_thrsh_te_2[ 0..0] (Type is Float32) attributes long_name: Second threshold for optical depth terrain score demerit (Type is String) units: 1 (Type is String) source: ATBD Terrain Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Second threshold of optical depth for terrain quality score demerit. (Default =0.3) (Type is String) skill_radmtry_total_penalty_2[ 0..0] (Type is Int32) attributes long_name: Second canopy score demerit value for total radiometry (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Second canopy quality score demerit for total radiometry. (Default =10) (Type is String) skill_mswflag_can_thrsh[ 0..0] (Type is Int32) attributes long_name: Threshold for MSW flag canopy score demerit (Type is String) units: 1 (Type is String) source: ATBD Canopy Quality Score (Type is String) contentType: auxiliaryInformation (Type is String) description: Threshold of MSW flag for canopy quality score demerit. (Default =1) (Type is String) shp_param[ 0..0] (Type is Float32) attributes long_name: Exponential coefficient for controlling the exponential decay of the filter window size as a function of number of signal photons. (Type is String) units: 1 (Type is String) source: ATBD Compute Filtering Window (Type is String) contentType: auxiliaryInformation (Type is String) description: Exponential coefficient of the filter window size as a function. (Default = 21.0E-06) (Type is String) del_sigma[ 0..0] (Type is Float32) attributes long_name: Step size for optimizing the standard deviation parameter of Gaussian function. (Type is String) units: 1 (Type is String) source: ATBD "Noise filtering via DRAGANN" (Type is String) contentType: auxiliaryInformation (Type is String) description: Step size for optimizing the standard deviation parameter of Gaussian function. (Default = 0.5) (Type is String) cloud_filter_switch[ 0..0] (Type is Int32) attributes long_name: cloud_filter switch (Type is String) units: 1 (Type is String) source: ATBD Cloud based filtering (Type is String) contentType: auxiliaryInformation (Type is String) description: Controls entrance to the cloud_filter subroutine. (Default = 0) (Type is String) n_dec_mode[ 0..0] (Type is Int32) attributes long_name: Mode decimal parameter (Type is String) units: 1 (Type is String) source: ATBD segment_terrain_height_mode (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of decimal places to consider in mode computation. (Default =1) (Type is String) ref_finalground_limit[ 0..0] (Type is Float32) attributes long_name: finalground threshold (Type is String) units: meters (Type is String) source: ATBD Final photon classification QA (Type is String) contentType: auxiliaryInformation (Type is String) description: Reference finalground limit used to reclassify signal as noise. (default = 150.0) (Type is String) p_static[ 0..0] (Type is Float32) attributes long_name: Dragann Parameter (Type is String) units: 1 (Type is String) source: ATBD "Noise filtering via DRAGANN" (Type is String) contentType: auxiliaryInformation (Type is String) description: Parameter for controlling the search radius in nearest neighbor search in DRAGANN. (Default = 20) (Type is String) gt3r(Type is Group) attributes atlas_pce: pce3 (Type is String) atlas_beam_type: weak (Type is String) groundtrack_id: gt3r (Type is String) atmosphere_profile: profile_3 (Type is String) atlas_spot_number: 6 (Type is String) sc_orientation: Backward (Type is String) land_segments(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) description: Contains data categorized as land at 100 meter intervals. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) Dimensions: [ /gt3r/land_segments/delta_time = 0..18238 ] longitude[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes long_name: longitude (Type is String) standard_name: longitude (Type is String) units: degrees (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) valid_min: -180. (Type is Float32) valid_max: 180. (Type is Float32) contentType: modelResult (Type is String) description: Longitude of the center-most signal photon within each segment. (Type is String) coordinates: delta_time latitude (Type is String) latitude[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes long_name: latitude (Type is String) standard_name: latitude (Type is String) units: degrees (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) valid_min: -90. (Type is Float32) valid_max: 90. (Type is Float32) contentType: modelResult (Type is String) description: Latitude of the center-most signal photon within each segment. (Type is String) coordinates: delta_time longitude (Type is String) delta_time[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float64) attributes long_name: mean_pass_time (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) contentType: referenceInformation (Type is String) description: Mean time for the segment in number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: latitude longitude (Type is String) rgt[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int16) attributes long_name: reference ground track (Type is String) units: 1 (Type is String) source: Operations (Type is String) valid_min: 1 (Type is Int16) valid_max: 1387 (Type is Int16) contentType: referenceInformation (Type is String) description: The reference ground track (RGT) is the track on the earth at which a specified unit vector within the observatory is pointed. Under nominal operating conditions, there will be no data collected along the RGT, as the RGT is spanned by GT3 and GT4. During slews or off-pointing, it is possible that ground tracks may intersect the RGT. The ICESat-2 mission has 1387 RGTs. (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_flag[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int8) attributes long_name: dem source flag (Type is String) units: 1 (Type is String) source: Atmosphere ATBD (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: referenceInformation (Type is String) description: Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=Global, 3=MSS, 4=Antarctic. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: none arctic global mss antarctic Undetermined (Type is String) flag_values: 0, 1, 2, 3, 4, 127 (Type is Int8) msw_flag[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int8) attributes long_name: multiple scattering warning flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: qualityInformation (Type is String) description: Multiple Scattering Warning flag. If no layers were detected, then msw_flag = 0. If blowing snow is detected and its estimated optical depth is greater than or equal to 0.5, then msw_flag = 5. If the blowing snow optical depth is less than 0.5, then msw_flag = 4. If no blowing snow is detected but there are cloud or aerosol layers detected, the msw_flag assumes values of 1 to 3 based on the height of the bottom of the lowest layer: < 1 km, msw_flag = 3; 1-3 km, msw_flag = 2; > 3km, msw_flag = 1. A value of 127 indicates that the signal to noise of the data was too low to reliably ascertain the presence of cloud or blowing snow. We expect values of 127 to occur only during daylight. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: cannot_determine no_layers layer_gt_3km layer_between_1_and_3_km layer_lt_1km blow_snow_od_lt_0.5 blow_snow_od_gt_0.5 (Type is String) flag_values: 127, 0, 1, 2, 3, 4, 5 (Type is Int8) permafrost_prob[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: permafrost probaility (Type is String) standard_name: permafrost_prob (Type is String) units: percent (Type is String) source: ESA CCI, ANC47 (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: referenceInformation (Type is String) description: Permafrost probability (0 - 100) derived via percent of permafrost within pixel cell area in ESA CCI 2019 northern hemisphere permafrost dataset (Type is String) coordinates: delta_time latitude longitude (Type is String) cloud_flag_atm[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: cloud flag atm (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 10 (Type is Int8) contentType: qualityInformation (Type is String) description: Cloud confidence flag from ATL09 that indicates the number of cloud or aerosol layers identified in each 25Hz atmospheric profile. If the flag is greater than 0, aerosols or clouds could be present. Valid range is 0 - 10. (Type is String) coordinates: delta_time latitude longitude (Type is String) snr[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: signal to noise ratio (Type is String) units: 1 (Type is String) source: ATBD Noise filtering via DRAGANN (Type is String) contentType: modelResult (Type is String) description: The signal to noise ratio of geolocated photons as determined by the ratio of the superset of ATL03 signal and DRAGANN found signal photons used for processing the ATL08 segments to the background photons (i.e. noise) within the same ATL08 segments. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_across[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas y (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Total cross-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_across. Sigma_atlas_y is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) layer_flag[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int8) attributes long_name: consolidated cloud flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: modelResult (Type is String) description: This flag is a combination of multiple flags (cloud_flag_atm, cloud_flag_asr, and bsnow_con) and takes daytime/nighttime into consideration. A value of 1 means clouds or blowing snow are likely present. A value of 0 indicates the likely absence of clouds or blowing snow. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: likely_clear likely_cloudy (Type is String) flag_values: 0, 1 (Type is Int8) segment_snowcover[ /gt3r/land_segments/delta_time= 0..18238] (Type is Byte) attributes long_name: segment snowcover (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_snowcover (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Daily snow/ice cover from ATL09 at the 25 Hz rate(275m) indicating likely presence of snow and ice within each segment. 0=ice free water; 1=snow free land; 2=snow; 3=ice. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: ice_free_water snow_free_land snow ice Undetermined (Type is String) flag_values: 0, 1, 2, 3, 255 (Type is Byte) beam_azimuth[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: beam azimuth (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Azimuth(in radians) of the unit pointing vector for the reference photon in the local ENU frame in radians. The angle is measured from north and positive towards East. (Type is String) coordinates: delta_time latitude longitude (Type is String) solar_azimuth[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes long_name: solar azimuth (Type is String) units: degrees_east (Type is String) source: ATL03 ATBD (Type is String) contentType: referenceInformation (Type is String) description: The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot. (Type is String) coordinates: delta_time latitude longitude (Type is String) psf_flag[ /gt3r/land_segments/delta_time= 0..18238] (Type is Byte) attributes long_name: point spread function flag (Type is String) units: 1 (Type is String) source: Land/Veg ATBD Refine Ground Estimates (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: referenceInformation (Type is String) description: Flag is set to 1 if the point spread function (computed as sigma_atlas_land) has exceeded the threshold (1 m) (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) segment_watermask[ /gt3r/land_segments/delta_time= 0..18238] (Type is Byte) attributes long_name: segment watermask (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_watermask (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Water mask(i.e. flag) indicating inland water as referenced from the Global Raster Water Mask(ANC33) at 250 m spatial resolution. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_water water Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) delta_time_end[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float64) attributes long_name: delta time end (Type is String) units: seconds since 2018-01-01 (Type is String) source: Derived (gps_seconds-gps_sec_offset) (Type is String) contentType: referenceInformation (Type is String) description: Time of the last photon contained within the data segment, in seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: delta_time latitude longitude (Type is String) segment_id_end[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int32) attributes long_name: end geolocation segment bin (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Geolocation segment number of the last photon in the land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) longitude_20m[ /gt3r/land_segments/delta_time= 0..18238] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: longitude of 20m segments (Type is String) units: degree (Type is String) source: ATBD Geosegment longitude (Type is String) valid_min: -180. (Type is Float32) valid_max: 180. (Type is Float32) contentType: modelResult (Type is String) description: Center longitude of 20m geosegments within each 100m land segment. (Type is String) coordinates: latitude longitude delta_time (Type is String) surf_type[ /gt3r/land_segments/delta_time= 0..18238] [ /ds_surf_type= 0..4] (Type is Int8) attributes long_name: surface type (Type is String) units: 1 (Type is String) source: ATL03 ATBD (Type is String) valid_min: 0 (Type is Int8) valid_max: 1 (Type is Int8) contentType: referenceInformation (Type is String) description: Flags describing which surface types this interval is associated with. 0=not type, 1=is type. Order of array is land, ocean, sea ice, land ice, inland water. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_type is_type (Type is String) flag_values: 0, 1 (Type is Int8) brightness_flag[ /gt3r/land_segments/delta_time= 0..18238] (Type is Byte) attributes long_name: brightness flag (Type is String) units: 1 (Type is String) source: Land ATBD Brightness_flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: Flag indicating that the ground surface is bright (e.g. snow-covered or other bright surfaces) (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_bright_surface bright_surface Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) segment_landcover[ /gt3r/land_segments/delta_time= 0..18238] (Type is Byte) attributes long_name: segment landcover (Type is String) units: 1 (Type is String) source: ATL08 ATBD segment_landcover (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: UN-FAO Land Cover Surface type classification as reference from Copernicus Land Cover(ANC18) at the 100m resolution. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: No_data Closed_forest_evergreen_needle_leaf Closed_forest_deciduous_needle_leaf Closed_forest_evergreen_broad_leaf Closed_forest_deciduous_broad_leaf Closed_forest_mixed Closed_forest_unknown Open_forest_evergreen_needle_leaf Open_forest_deciduous_needle_leaf Open_forest_evergreen_broad_leaf Open_forest_deciduous_broad_leaf Open_forest_mixed Open_forest_unknown Shrubs Herbaceous Herbaceous_wetleand Moss_and_lichen Bare_sparse_vegetation Cultivated_and_managed_vegetation_agriculture Urban_built_up Snow_and_ice Permanent_water_bodies Open_sea Undetermined (Type is String) flag_values: 0, 111, 113, 112, 114, 115, 116, 121, 123, 122, 124, 125, 126, 20, 30, 90, 100, 60, 40, 50, 70, 80, 200, 255 (Type is Byte) ph_removal_flag[ /gt3r/land_segments/delta_time= 0..18238] (Type is Byte) attributes long_name: ph removal flag (Type is String) units: 1 (Type is String) source: ATBD Final photon classification QA (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Flag indicating more than ph_removal_percent_limit (default 50.0) removed from land segment due to failing QA tests (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) asr[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: apparent surface reflectance (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: auxiliaryInformation (Type is String) description: Apparent surface reflectance (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_atlas_land[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas land (Type is String) units: 1 (Type is String) source: Land ATBD Refine Ground Estimates (Type is String) contentType: referenceInformation (Type is String) description: Total vertical geolocation error due to ranging and local surface slope. The parameter is computed for ATL08 as described in equation 1.2 ATL08 ATBD. (Type is String) coordinates: delta_time latitude longitude (Type is String) segment_id_beg[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int32) attributes long_name: begin geolocation segment bin (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Geolocation segment number of the first photon in the land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_along[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas x (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Total along-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_along. Sigma_atlas_x is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_h[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: dem height (Type is String) units: meters (Type is String) source: Arctic, Antarctic, Global, MSS DEM (Type is String) contentType: referenceInformation (Type is String) description: Best available DEM (in priority of Arctic/Antarctic/Global/MSS) value at the geolocation point. Height is in meters above the WGS84 Ellipsoid. (Type is String) coordinates: delta_time latitude longitude (Type is String) beam_coelev[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: beam co-elevation (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Co-elevation (CE) is direction from vertical of the laser beam as seen by an observer located at the laser ground spot. (Type is String) coordinates: delta_time latitude longitude (Type is String) sat_flag[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int8) attributes long_name: saturation flag (Type is String) units: 1 (Type is String) source: ATL03, Land ATBD Saturation Flag (Type is String) valid_min: -1 (Type is Int8) valid_max: 127 (Type is Int8) contentType: auxiliaryInformation (Type is String) description: Flag derived from full_sat_fract on the ATL03 data product, averaged over 5 geosegments in 100m land segment (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_saturation_detected saturation_detected not_enough_valid_data Undetermined (Type is String) flag_values: 0, 1, -1, 127 (Type is Int8) sigma_topo[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: sigma atlas topo (Type is String) units: 1 (Type is String) source: Land ATBD Refine Ground Estimates (Type is String) contentType: referenceInformation (Type is String) description: Total uncertainty that include sigma_h plus geolocation uncertainty due to local slope (equation 1.3). The local slope is multiplied by the geolocation uncertainty factor. This will be used to determine the total vertical geolocation error due to ranging and local slope. (Type is String) coordinates: delta_time latitude longitude (Type is String) night_flag[ /gt3r/land_segments/delta_time= 0..18238] (Type is Byte) attributes long_name: night flag (Type is String) units: 1 (Type is String) source: Land ATBD Night_Flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Flag indicating the data were acquired in night conditions: 0=day, 1=night. Flag is derived from solar elevation at the geolocated segment. IF solar elevation is above threshold it is day, if not then it is night. Threshold is set in atlas_l3a_const_mod. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: day night Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) delta_time_beg[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float64) attributes long_name: delta time begin (Type is String) units: seconds since 2018-01-01 (Type is String) source: Derived (gps_seconds-gps_sec_offset) (Type is String) contentType: referenceInformation (Type is String) description: Time of the first photon contained within the data segment, in seconds since the ATLAS SDP GPS Epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: delta_time latitude longitude (Type is String) sigma_h[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: height uncertainty (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m) provided at the geolocation segment rate on ATL03. Sigma_h is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) last_seg_extend[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes long_name: last segment extended (Type is String) standard_name: last_seg_extend (Type is String) units: kilometers (Type is String) source: Land ATBD Preparing ATL03 data for input (Type is String) contentType: auxiliaryInformation (Type is String) description: The distance (km) that the last ATL08 processing segment in a file is either extended or overlapped with the previous ATL08 processing segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) column_od_asr[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Column optical depth from ASR (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: auxiliaryInformation (Type is String) description: Optical depth of atmosphere column based on apparent surface reflectance and the assumed actual surface reflectance. (Type is String) coordinates: delta_time latitude longitude (Type is String) atlas_pa[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: atlas pointing angle (Type is String) units: radians (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Off nadir pointing angle (in radians) of the satellite to increase spatial sampling in the non-polar regions. ATLAS_PA =radians(90degs-beam_coelev). (Type is String) coordinates: delta_time latitude longitude (Type is String) ph_ndx_beg[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int64) attributes long_name: photon index begin (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Index (1-based) within the photon-rate data (/land_segments/photons) of the first photon within this each land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) solar_elevation[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes long_name: solar elevation (Type is String) units: degrees (Type is String) source: ATL03 ATBD (Type is String) contentType: referenceInformation (Type is String) description: Solar Angle above or below the plane tangent to the ellipsoid surface at the laser spot. Positive values mean the sun is above the horizon, while negative values mean it is below the horizon. The effect of atmospheric refraction is not included. This is a low precision value, with approximately TBD degree accuracy. (Type is String) coordinates: delta_time latitude longitude (Type is String) latitude_20m[ /gt3r/land_segments/delta_time= 0..18238] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: latitude of 20m segments (Type is String) units: degree (Type is String) source: ATBD Geosegment latitude (Type is String) valid_min: -90. (Type is Float32) valid_max: 90. (Type is Float32) contentType: modelResult (Type is String) description: Center latitude of 20m geosegments within each 100m land segment. (Type is String) coordinates: latitude longitude delta_time (Type is String) cloud_fold_flag[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int8) attributes long_name: cloud folding flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 127 (Type is Int8) contentType: modelResult (Type is String) description: Flag that indicates this profile likely contains cloud signal folded down from above 15 km to the last 2-3 km of the profile. See ATL09 ATBD Table 3.9 for detailed flag value meanings. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: no_folding goes5_indicates profile_indicates both_indicate outside_limits (Type is String) flag_values: 0, 1, 2, 3, 127 (Type is Int8) n_seg_ph[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int32) attributes long_name: number of photons (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of photons within each land segment. (Type is String) coordinates: delta_time latitude longitude (Type is String) terrain_flg[ /gt3r/land_segments/delta_time= 0..18238] (Type is Byte) attributes long_name: terrain flag (Type is String) units: 1 (Type is String) source: Land ATBD Segment_terrain flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: auxiliaryInformation (Type is String) description: Terrain flag quality check to indicate a deviation above a threshold from the reference DEM height reported on the product. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) urban_flag[ /gt3r/land_segments/delta_time= 0..18238] (Type is Byte) attributes long_name: segment urban flag (Type is String) units: 1 (Type is String) source: Land ATBD Urban_flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: The urban flag indicates that a segment is likely located over an urban area as determined by coincident pixels in the Global Urban Footprint (GUF) 0.4 arcsecond product. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: not_urban urban Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) permafrost_alt[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: permafrost active layer thickness (Type is String) standard_name: permafrost_alt (Type is String) units: meters (Type is String) source: ESA CCI, ANC47 (Type is String) valid_min: 0. (Type is Float32) valid_max: 100. (Type is Float32) contentType: referenceInformation (Type is String) description: Permafrost active layer thickness (m) from ESA CCI 2019 northern hemisphere permafrost dataset (Type is String) coordinates: delta_time latitude longitude (Type is String) dem_removal_flag[ /gt3r/land_segments/delta_time= 0..18238] (Type is Byte) attributes long_name: dem removal flag (Type is String) units: 1 (Type is String) source: ATBD Segment reference DEM removal flag (Type is String) valid_min: 0 (Type is Byte) valid_max: 255 (Type is Byte) contentType: qualityInformation (Type is String) description: Flag indicating more than dem_removal_percent_limit (default 20.0) removed from land segment due to failing DEM-QA tests (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: below_threshold above_threshold Undetermined (Type is String) flag_values: 0, 1, 255 (Type is Byte) h_dif_ref[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: h dif from reference (Type is String) units: meters (Type is String) source: Land ATBD segment parameters for Land Products (Type is String) contentType: modelResult (Type is String) description: Difference between h_te_median and ref_DEM (Type is String) coordinates: delta_time latitude longitude (Type is String) canopy(Type is Group) attributes description: Contains height parameters based on the land algorithm. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) h_canopy[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: height canopy (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: 98% height of all the individual canopy relative heights for the segment above the estimated terrain surface. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) canopy_rh_conf[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int8) attributes units: 1 (Type is String) long_name: canopy relative height confidence (Type is String) source: Land/Veg ATBD Vegetation Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 2 (Type is Int8) contentType: modelResult (Type is String) description: Canopy relative height confidence flag based on percentage of ground and canopy photons within a segment: 0 (<5% canopy), 1 (>5% canopy, <5% ground), 2 (>5% canopy, >5% ground). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: <5%_canopy >=5%_canopy_<5%_ground >=5%_canopy_>=5%_ground (Type is String) flag_values: 0, 1, 2 (Type is Int8) h_median_canopy_abs[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute segment median canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The median of individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_min_canopy[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: minimum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of relative individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_mean_canopy_abs[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute mean canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Mean of the individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_median_canopy[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: median canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The median of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. This parameter should be equivalent to RH50 reported in the literature. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_abs[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute segment canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The 98% height of all the absolute individual canopy heights referenced above the WGS84 ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) toc_roughness[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: top of canopy roughness (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Standard deviation of the relative heights of all photons classified as top of canopy within the segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_min_canopy_abs[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute minimum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of absolute individual canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_dif_canopy[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy diff to median height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Difference between h_canopy and h_median_canopy (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_quad[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy quadratic mean (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The quadratic mean height of individual classified relative canopy photon heights above the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_20m[ /gt3r/land_segments/delta_time= 0..18238] [ /ds_geosegments= 0..4] (Type is Float32) attributes units: m (Type is String) _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy height 20m (Type is String) source: ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Canopy height for each 20m geosegment with each 100m land segment. (Type is String) coordinates: ../latitude ../longitude ../delta_time (Type is String) n_ca_photons[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int32) attributes long_name: number canopy photons (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The number of photons classified as canopy within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_can[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Canopy photon rate (Type is String) units: s^-1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Calculated photon rate of canopy photons within each 100m segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) centroid_height[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: centroid height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Optical centroid of all photons classified as either canopy or ground points within the segment. The heights used in this calculation are absolute heights above the reference ellipsoid. This parameter is equivalent to the centroid height produced ICESat GLA14. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) canopy_h_metrics_abs[ /gt3r/land_segments/delta_time= 0..18238] [ /ds_metrics= 0..17] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy absolute height metrics (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Height metrics based on the cumulative distribution of absolute canopy heights above the WGS84 Ellipsoid. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) can_noise[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy noise rate (Type is String) units: count/meter (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Number of noise photons calculated that fall within the canopy height for each 100 m segment based on ATL03 background rate parameters. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_mean_canopy[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mean canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Mean of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) subset_can_flag[ /gt3r/land_segments/delta_time= 0..18238] [ /ds_geosegments= 0..4] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: subset canopy flag (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: -1 (Type is Int8) valid_max: 1 (Type is Int8) contentType: modelResult (Type is String) description: Quality flag indicating the canopy photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: no_photon_data_within_geosegment no_canopy_photons_within_geosegment canopy_photons_present_within_geosegment (Type is String) flag_values: -1, 0, 1 (Type is Int8) canopy_h_metrics[ /gt3r/land_segments/delta_time= 0..18238] [ /ds_metrics= 0..17] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy height metrics (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Height metrics based on the cumulative distribution of relative canopy heights above the interpolated ground surface. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) n_toc_photons[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int32) attributes long_name: number top of canopy photons (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: The number of photons classified as top of canopy within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_max_canopy_abs[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: absolute maximum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Maximum of individual absolute canopy heights within segment referenced above the WGS84 ellipsoid. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_canopy_uncertainty[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment canopy height uncertainty (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: qualityInformation (Type is String) description: Uncertainty of the relative canopy heights for the segment. Incorporates all systematic uncertainties as well as uncertainty from errors of identified photons. See section 1 and equations 1.4 and 1.5 of the ATL08 ATBD. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_can_nr[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: noise reduced number of canopy photons (Type is String) units: s^-1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Noise removed photon canopy rate within each 100 m segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) can_quality_score[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int8) attributes units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: modelResult (Type is String) description: Canopy quality score based on coincident conditions, from ATL08 ATBD section titled "Canopy Quality Score". (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) _FillValue: 127 (Type is Int8) long_name: canopy quality score (Type is String) canopy_openness[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: canopy openness (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Standard Deviation of all photons classified as canopy photons within the segment to provide inference of canopy openness. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_max_canopy[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: maximum canopy height (Type is String) units: meters (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: modelResult (Type is String) description: Relative maximum of individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. Should be equivalent to RH100 metric reported in the literature. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) segment_cover[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int16) attributes _FillValue: 32767 (Type is Int16) long_name: canopy cover percentage (Type is String) units: 1 (Type is String) source: Land ATBD Vegetation Parameters (Type is String) contentType: auxiliaryInformation (Type is String) description: Average percentage value of the valid (value <= 100) Copernicus fractional cover product for each 100 m segment. This data is temporally static, and is the summation of forest and shrub land cover fractions. Source data from: https://land.copernicus.eu/en/products/global-dynamic-land-cover/copernicus-global-land-service-land-cover-100m-collection-3-epoch-2019-globe . (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) terrain(Type is Group) attributes description: Contains terrain parameters at a 100m aggregation. (Type is String) data_rate: Data are stored as aggregates of 100 meters. (Type is String) h_te_uncertainty[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: uncertainty of h_te_mean (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Uncertainty of the mean terrain height for the segment. This uncertainty incorporates all systematic uncertainties(e.g. timing orbits, geolocation,etc.) as well as uncertainty from errors of identified photons. This parameter is described in section 1, equation 1.4 in ATL08 ATBD. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_mean[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mean terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The mean of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_min[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: minimum terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The minimum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) photon_rate_te[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Terrain photon rate (Type is String) units: s^-1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: 0. (Type is Float32) contentType: modelResult (Type is String) description: Calculated photon rate of terrain photons within each 100m segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_interp[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: interpolated terrain surface height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Interpolated terrain surface height above the WGS84 Ellipsoid at the midpoint of the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_max[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: maximum terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The maximum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_rh25[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes units: meters (Type is String) _FillValue: 3.402823466e+38 (Type is Float32) long_name: Terrain height 25% percentile (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The terrain elevation from the 25% height. The classified ground photons are sorted into a cumulative distribution and the height associated with the 25% height for that segment is reported. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_skew[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: skew of terrain heights (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The skewness of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_best_fit_20m[ /gt3r/land_segments/delta_time= 0..18238] [ /ds_geosegments= 0..4] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: best fit 20m (Type is String) units: m (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: Best fit terrain height to center of each 20m geosegment within each 100m land segment. (Type is String) coordinates: ../latitude ../longitude ../delta_time (Type is String) h_te_median[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: median terrain height (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The median of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_best_fit[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain height best fit (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The best fit terrain elevation at the the mid-point location of each 100m segment. The mid-segment terrain elevation is determined by selecting the best of three fits- linear, 3rd order and 4th order polynomials - to the terrain photons and interpolating the elevation at the mid-point location of the 100 m segment. For the linear fit, a slope correction and weighting is applied to each ground photon based on the distance to the slope height at the center of the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_std[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain roughness (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The standard deviation of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) terrain_slope[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: segment terrain slope (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The along-track slope of terrain, within each segment;computed by a linear fit of terrain classified photons. Slope is in units of delta height over delta along track distance. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) subset_te_flag[ /gt3r/land_segments/delta_time= 0..18238] [ /ds_geosegments= 0..4] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: subset terrain flag (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: -1 (Type is Int8) valid_max: 1 (Type is Int8) contentType: modelResult (Type is String) description: Quality flag indicating the terrain photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: no_photon_data_within_geosegment no_terrain_photons_within_geosegment terrain_photons_present_within_geosegment (Type is String) flag_values: -1, 0, 1 (Type is Int8) n_te_photons[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int32) attributes long_name: number of ground photons (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The number of the photons classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_te_mode[ /gt3r/land_segments/delta_time= 0..18238] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mode of terrain heights (Type is String) units: meters (Type is String) source: Land ATBD Land Parameters (Type is String) contentType: modelResult (Type is String) description: The mode of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) te_quality_score[ /gt3r/land_segments/delta_time= 0..18238] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: terrain quality score (Type is String) units: 1 (Type is String) source: Land ATBD Land Parameters (Type is String) valid_min: 0 (Type is Int8) valid_max: 100 (Type is Int8) contentType: modelResult (Type is String) description: Quality score based on coincident conditions, from ATL08 ATBD section titled "Terrain Quality Score". (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) signal_photons(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) description: Contains parameters related to individual photons. (Type is String) data_rate: Data are stored at the signal-photon classification rate. (Type is String) Dimensions: [ /gt3r/signal_photons/delta_time = 0..1518454 ] delta_time[ /gt3r/signal_photons/delta_time= 0..1518454] (Type is Float64) attributes long_name: delta time (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: ATL03 (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) classed_pc_indx[ /gt3r/signal_photons/delta_time= 0..1518454] (Type is Int32) attributes units: 1 (Type is String) long_name: indicies of classed photons (Type is String) source: Retained from prior a_alt_science_ph packet (Type is String) contentType: referenceInformation (Type is String) description: Index (1-based) of the ATL08 classified signal photon from the start of the ATL03 geolocation segment specified on the ATL08 product at the photon rate in the corresponding parameter, ph_segment_id. This index traces back to specific photon within a 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group. (Type is String) coordinates: delta_time (Type is String) ph_h[ /gt3r/signal_photons/delta_time= 0..1518454] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: relative photon height (Type is String) standard_name: height (Type is String) units: meters (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: physicalMeasurement (Type is String) description: Height of photons above interpolated land surface (Type is String) coordinates: delta_time (Type is String) d_flag[ /gt3r/signal_photons/delta_time= 0..1518454] (Type is Int8) attributes long_name: dragann flag (Type is String) units: 1 (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: qualityInformation (Type is String) description: Flag indicating the labeling of DRAGANN noise filtering for a given photon. (Type is String) coordinates: delta_time (Type is String) flag_meanings: noise signal (Type is String) flag_values: 0, 1 (Type is Int8) classed_pc_flag[ /gt3r/signal_photons/delta_time= 0..1518454] (Type is Int8) attributes long_name: photon land atbd classification (Type is String) units: 1 (Type is String) source: Land ATBD Subgroup: Photons (Type is String) contentType: modelResult (Type is String) description: Land Vegetation ATBD classification flag for each photon as either noise, ground, canopy, and top of canopy. 0 = noise, 1 = ground, 2 = canopy, or 3 = top of canopy. (Type is String) coordinates: delta_time (Type is String) flag_meanings: noise ground canopy top_of_canopy (Type is String) flag_values: 0, 1, 2, 3 (Type is Int8) ph_segment_id[ /gt3r/signal_photons/delta_time= 0..1518454] (Type is Int32) attributes long_name: segment id of photon (Type is String) units: 1 (Type is String) source: Retained from prior a_alt_science_ph packet (Type is String) contentType: referenceInformation (Type is String) description: Segment ID of photons tracing back to specific 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the photon on ATL03 is the segment_id, orbit, and classed_pc_indx. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group. (Type is String) coordinates: delta_time (Type is String)

dataset: ATL08_20200716202251_03280806_007_01.h5
(dmr)

OPeNDAP Hyrax (1.17.1-536)
Documentation Questions? Contact Support

dataset: ATL08_20200716202251_03280806_007_01.h5 (dmr)

OPeNDAP Hyrax (1.17.1-536) Documentation Questions? Contact Support

dataset: ATL08_20200716202251_03280806_007_01.h5
(dmr)

OPeNDAP Hyrax (1.17.1-536)
Documentation Questions? Contact Support