DAP4 Data Request Form ATL08_20181016124656_02730110_002_01.h5

dataset: ATL08_20181016124656_02730110_002_01.h5
(dmr)

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Global Attributes
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    • granule_type: ATL08 (Type is String)
    • short_name: ATL08 (Type is String)
    • level: 3A (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)
    • contributor_name: Thomas E 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)
    • Conventions: CF-1.6 (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)
    • identifier_product_doi: 10.5067/ATLAS/ATL08.001 (Type is String)
    • identifier_product_doi_authority: http://dx.doi.org (Type is String)
    • identifier_product_type: ATL08 (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: 2019-08-22T21:07:29.000000Z (Type is String)
    • hdfversion: HDF5 1.10.3 (Type is String)
    • history: 2019-08-22T21:07:29.000000Z;58383667-e9b3-3639-a8de-168784ceb5e9;Created by PGE atlas_l3a_ld Version 3.2 (Type is String)
    • identifier_file_uuid: 58383667-e9b3-3639-a8de-168784ceb5e9 (Type is String)
    • identifier_product_format_version: 3.2 (Type is String)
    • time_coverage_duration: 461. (Type is Float64)
    • time_coverage_end: 2018-10-16T12:54:37.000000Z (Type is String)
    • time_coverage_start: 2018-10-16T12:46:56.000000Z (Type is String)
    • geospatial_lat_min: -78.804759009697463 (Type is Float64)
    • geospatial_lon_min: -153.81953845733065 (Type is Float64)
    • geospatial_lat_max: -78.498235427544756 (Type is Float64)
    • geospatial_lon_max: -153.32549412458567 (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 (Type is String)
    • identifier_file_product_type: ATL08 (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)
Global Dimensions
None
Variables
ds_metrics[ 0..8] (Type is Int8)
  • attributes
    • units: 1 (Type is String)
    • contentType: referenceInformation (Type is String)
    • long_name: Metrics (Type is String)
    • description: Dimension scale for metrics. (Type is String)
    • flag_meanings: metrics1 metrics2 metrics3 metrics4 metrics5 metrics6 metrics7 metrics8 metrics9 (Type is String)
    • flag_values: 1, 2, 3, 4, 5, 6, 7, 8, 9 (Type is Int8)
    • valid_min: 1 (Type is Int8)
    • valid_max: 4 (Type is Int8)
ds_surf_type[ 0..4] (Type is Int32)
  • attributes
    • units: 1 (Type is String)
    • contentType: auxiliaryInformation (Type is String)
    • long_name: Surface Type Dimension Scale (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)
    • valid_min: 1 (Type is Int32)
    • valid_max: 5 (Type is Int32)
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)
  • crossing_time[ 0..0] (Type is Float64)
    • attributes
      • units: seconds since 2018-01-01 (Type is String)
      • contentType: referenceInformation (Type is String)
      • long_name: Ascending Node Crossing Time (Type is String)
      • standard_name: time (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)
      • source: POD/PPD (Type is String)
  • sc_orient_time[ 0..0] (Type is Float64)
    • attributes
      • units: seconds since 2018-01-01 (Type is String)
      • contentType: referenceInformation (Type is String)
      • long_name: Time of Last Spacecraft Orientation Change (Type is String)
      • standard_name: time (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)
      • source: POD/PPD (Type is String)
  • orbit_number[ 0..0] (Type is UInt16)
    • attributes
      • units: 1 (Type is String)
      • contentType: referenceInformation (Type is String)
      • long_name: Orbit Number (Type is String)
      • description: Unique identifying number for each planned ICESat-2 orbit. (Type is String)
      • source: Operations (Type is String)
      • coordinates: crossing_time (Type is String)
      • valid_min: 1 (Type is UInt16)
      • valid_max: 65000 (Type is UInt16)
  • lan[ 0..0] (Type is Float64)
    • attributes
      • units: degrees_east (Type is String)
      • contentType: referenceInformation (Type is String)
      • long_name: Ascending Node Longitude (Type is String)
      • description: Longitude at the ascending node crossing. (Type is String)
      • source: POD/PPD (Type is String)
      • coordinates: crossing_time (Type is String)
      • valid_min: -180. (Type is Float64)
      • valid_max: 180. (Type is Float64)
  • sc_orient[ 0..0] (Type is Int8)
    • attributes
      • units: 1 (Type is String)
      • contentType: referenceInformation (Type is String)
      • long_name: Spacecraft Orientation (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)
      • source: POD/PPD (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)
      • valid_min: 0 (Type is Int8)
      • valid_max: 2 (Type is Int8)
  • rgt[ 0..0] (Type is Int16)
    • attributes
      • units: 1 (Type is String)
      • contentType: referenceInformation (Type is String)
      • long_name: Reference Ground track (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)
      • source: POD/PPD (Type is String)
      • coordinates: crossing_time (Type is String)
      • valid_min: 1 (Type is Int16)
      • valid_max: 1387 (Type is Int16)
  • cycle_number[ 0..0] (Type is Int8)
    • attributes
      • units: 1 (Type is String)
      • contentType: referenceInformation (Type is String)
      • long_name: Cycle Number (Type is String)
      • description: A count of the number of exact repeats of this reference orbit. (Type is String)
      • source: Operations (Type is String)
      • coordinates: crossing_time (Type is String)
      • valid_min: 0 (Type is Int8)
      • valid_max: 50 (Type is Int8)
METADATA(Type is Group)
  • attributes
    • Description: ISO19115 Structured Metadata Represented within HDF5 (Type is String)
    • iso_19139_dataset_xml: <?xml version="1.0"?> <gmd:DS_Series xsi:schemaLocation="http://www.isotc211.org/2005/gmi http://cdn.earthdata.nasa.gov/iso/schema/1.0/ISO19115-2_EOS.xsd" xmlns:eos="http://earthdata.nasa.gov/schema/eos" xmlns:gco="http://www.isotc211.org/2005/gco" xmlns:gmd="http://www.isotc211.org/2005/gmd" xmlns:gmi="http://www.isotc211.org/2005/gmi" xmlns:gml="http://www.opengis.net/gml/3.2" xmlns:gmx="http://www.isotc211.org/2005/gmx" xmlns:gsr="http://www.isotc211.org/2005/gsr" xmlns:gss="http://www.isotc211.org/2005/gss" xmlns:gts="http://www.isotc211.org/2005/gts" xmlns:srv="http://www.isotc211.org/2005/srv" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <gmd:composedOf> <gmd:DS_DataSet> <gmd:has> <gmi:MI_Metadata> <gmd:fileIdentifier> <gmx:FileName>ATL08_20181016124656_02730110_002_01.h5</gmx:FileName> </gmd:fileIdentifier> <gmd:contact> <gmd:CI_ResponsibleParty> <gmd:organisationName> <gco:CharacterString>NSIDC DAAC &gt; National Snow and Ice Data Center DAAC</gco:CharacterString> </gmd:organisationName> <gmd:contactInfo> <gmd:CI_Contact> <gmd:address> <gmd:CI_Address> <gmd:electronicMailAddress> <gco:CharacterString>nsidc@nsidc.org</gco:CharacterString> </gmd:electronicMailAddress> </gmd:CI_Address> </gmd:address> <gmd:onlineResource> <gmd:CI_OnlineResource> <gmd:linkage> <gmd:URL>http://nsidc.org/daac/</gmd:URL> </gmd:linkage> </gmd:CI_OnlineResource> </gmd:onlineResource> </gmd:CI_Contact> </gmd:contactInfo> <gmd:role> <gmd:CI_RoleCode codeList="http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#CI_RoleCode" codeListValue="pointOfContact">pointOfContact</gmd:CI_RoleCode> </gmd:role> </gmd:CI_ResponsibleParty> </gmd:contact> <gmd:dateStamp> <gco:DateTime>2019-08-22T21:07:29.000000Z</gco:DateTime> </gmd:dateStamp> <gmd:identificationInfo> <gmd:MD_DataIdentification> <gmd:citation> <gmd:CI_Citation> <gmd:title> <gmx:FileName>ATL08_20181016124656_02730110_002_01.h5</gmx:FileName> </gmd:title> <gmd:date> <gmd:CI_Date> <gmd:date> <gco:DateTime>2019-08-22T21:07:29.000000Z</gco:DateTime> </gmd:date> <gmd:dateType> <gmd:CI_DateTypeCode codeList="http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#CI_DateTypeCode" codeListValue="creation">creation</gmd:CI_DateTypeCode> </gmd:dateType> </gmd:CI_Date> </gmd:date> <gmd:identifier> <gmd:MD_Identifier> <gmd:code> <gco:CharacterString>ATL08</gco:CharacterString> </gmd:code> <gmd:description> <gco:CharacterString>The ECS Short Name</gco:CharacterString> </gmd:description> </gmd:MD_Identifier> </gmd:identifier> <gmd:identifier> <gmd:MD_Identifier> <gmd:code> <gco:CharacterString>002</gco:CharacterString> </gmd:code> <gmd:description> <gco:CharacterString>The ECS Version ID</gco:CharacterString> </gmd:description> </gmd:MD_Identifier> </gmd:identifier> <gmd:identifier> <gmd:MD_Identifier> <gmd:code> <gco:CharacterString>ATL08_20181016124656_02730110_002_01.h5</gco:CharacterString> </gmd:code> <gmd:description> <gco:CharacterString>ProducerGranuleId</gco:CharacterString> </gmd:description> </gmd:MD_Identifier> </gmd:identifier> </gmd:CI_Citation> </gmd:citation> <gmd:abstract> <gco:CharacterString>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.</gco:CharacterString> </gmd:abstract> <gmd:aggregationInfo> <gmd:MD_AggregateInformation> <gmd:aggregateDataSetName> <gmd:CI_Citation> <gmd:title> <gco:CharacterString>ATL08</gco:CharacterString> </gmd:title> <gmd:date gco:nilReason="unknown"/> <gmd:edition> <gco:CharacterString>002</gco:CharacterString> </gmd:edition> </gmd:CI_Citation> </gmd:aggregateDataSetName> <gmd:associationType> <gmd:DS_AssociationTypeCode codeList="http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#DS_AssociationTypeCode" codeListValue="largerWorkCitation">largerWorkCitation</gmd:DS_AssociationTypeCode> </gmd:associationType> </gmd:MD_AggregateInformation> </gmd:aggregationInfo> <gmd:language> <gco:CharacterString>eng</gco:CharacterString> </gmd:language> <gmd:extent> <gmd:EX_Extent id="boundingExtent"> <gmd:geographicElement> <gmd:EX_GeographicDescription id="Orbit"> <gmd:geographicIdentifier> <gmd:MD_Identifier> <gmd:code> <gco:CharacterString>AscendingCrossing: 55.413850781199955 StartLatitude: -50.000000000000000 StartDirection:D EndLatitude: -79.000000000000000 EndDirection: D</gco:CharacterString> </gmd:code> <gmd:codeSpace> <gco:CharacterString>gov.nasa.esdis.umm.orbitparameters</gco:CharacterString> </gmd:codeSpace> <gmd:description> <gco:CharacterString>OrbitParameters</gco:CharacterString> </gmd:description> </gmd:MD_Identifier> </gmd:geographicIdentifier> </gmd:EX_GeographicDescription> </gmd:geographicElement> <gmd:geographicElement> <gmd:EX_GeographicDescription id="OrbitCalculatedSpatialDomains0"> <gmd:geographicIdentifier> <gmd:MD_Identifier> <gmd:code> <gco:CharacterString>OrbitNumber: 474 EquatorCrossingLongitude: 55.413850781199955 EquatorCrossingDateTime: 2018-10-16T11:46:46.152995Z</gco:CharacterString> </gmd:code> <gmd:codeSpace> <gco:CharacterString>gov.nasa.esdis.umm.orbitcalculatedspatialdomains</gco:CharacterString> </gmd:codeSpace> <gmd:description> <gco:CharacterString>OrbitCalculatedSpatialDomains</gco:CharacterString> </gmd:description> </gmd:MD_Identifier> </gmd:geographicIdentifier> </gmd:EX_GeographicDescription> </gmd:geographicElement> <gmd:temporalElement> <gmd:EX_TemporalExtent> <gmd:extent> <gml:TimePeriod gml:id="TIME_PERIOD_ID"> <gml:beginPosition>2018-10-16T12:54:26.671899Z</gml:beginPosition> <gml:endPosition>2018-10-16T12:54:31.250499Z</gml:endPosition> </gml:TimePeriod> </gmd:extent> </gmd:EX_TemporalExtent> </gmd:temporalElement> </gmd:EX_Extent> </gmd:extent> </gmd:MD_DataIdentification> </gmd:identificationInfo> <gmd:dataQualityInfo> <gmd:DQ_DataQuality> <gmd:scope> <gmd:DQ_Scope> <gmd:level> <gmd:MD_ScopeCode codeList="http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#MD_ScopeCode" codeListValue="dataset">dataset</gmd:MD_ScopeCode> </gmd:level> </gmd:DQ_Scope> </gmd:scope> <gmd:lineage> <gmd:LI_Lineage> <gmd:processStep> <gmi:LE_ProcessStep> <gmd:description> <gco:CharacterString>2019-08-22T21:07:29.000000Z;58383667-e9b3-3639-a8de-168784ceb5e9;Created by PGE atlas_l3a_ld Version 3.2</gco:CharacterString> </gmd:description> <gmd:dateTime> <gco:DateTime>2019-08-22T21:07:29.000000Z</gco:DateTime> </gmd:dateTime> </gmi:LE_ProcessStep> </gmd:processStep> </gmd:LI_Lineage> </gmd:lineage> </gmd:DQ_DataQuality> </gmd:dataQualityInfo> </gmi:MI_Metadata> </gmd:has> </gmd:DS_DataSet> </gmd:composedOf> <gmd:seriesMetadata gco:nilReason="missing"/> </gmd:DS_Series> (Type is String)
    • iso_19139_series_xml: <?xml version="1.0" encoding="UTF-8"?> <gmd:DS_Series xmlns:eos="http://earthdata.nasa.gov/schema/eos" xmlns:gco="http://www.isotc211.org/2005/gco" xmlns:gmd="http://www.isotc211.org/2005/gmd" xmlns:gmi="http://www.isotc211.org/2005/gmi" xmlns:gml="http://www.opengis.net/gml/3.2" xmlns:gmx="http://www.isotc211.org/2005/gmx" xmlns:gsr="http://www.isotc211.org/2005/gsr" xmlns:gss="http://www.isotc211.org/2005/gss" xmlns:gts="http://www.isotc211.org/2005/gts" xmlns:srv="http://www.isotc211.org/2005/srv" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.isotc211.org/2005/gmi http://cdn.earthdata.nasa.gov/iso/schema/1.0/ISO19115-2_EOS.xsd"> <gmd:composedOf gco:nilReason="inapplicable"/> <gmd:seriesMetadata> <gmi:MI_Metadata> <gmd:fileIdentifier> <gco:CharacterString>ATL08.002</gco:CharacterString> </gmd:fileIdentifier> <gmd:language> <gco:CharacterString>eng</gco:CharacterString> </gmd:language> <gmd:characterSet> <gmd:MD_CharacterSetCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#MD_CharacterSetCode" codeListValue="utf8">utf8</gmd:MD_CharacterSetCode> </gmd:characterSet> <gmd:hierarchyLevel> <gmd:MD_ScopeCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#MD_ScopeCode" codeListValue="series">series</gmd:MD_ScopeCode> </gmd:hierarchyLevel> <gmd:contact> <gmd:CI_ResponsibleParty> <gmd:organisationName> <gco:CharacterString>NSIDC DAAC &gt; NASA National Snow and Ice Data Center Distributed Active Archive Center</gco:CharacterString> </gmd:organisationName> <gmd:contactInfo> <gmd:CI_Contact id="NSIDC_DAAC_CONTACT_ID"> <gmd:phone> <gmd:CI_Telephone> <gmd:voice> <gco:CharacterString>303-492-6199</gco:CharacterString> </gmd:voice> <gmd:facsimile> <gco:CharacterString>303-492-2468</gco:CharacterString> </gmd:facsimile> </gmd:CI_Telephone> </gmd:phone> <gmd:address> <gmd:CI_Address> <gmd:deliveryPoint> <gco:CharacterString>1540 30th St Campus Box 449</gco:CharacterString> </gmd:deliveryPoint> <gmd:city> <gco:CharacterString>Boulder</gco:CharacterString> </gmd:city> <gmd:administrativeArea> <gco:CharacterString>Colorado</gco:CharacterString> </gmd:administrativeArea> <gmd:postalCode> <gco:CharacterString>80309-0449</gco:CharacterString> </gmd:postalCode> <gmd:country> <gco:CharacterString>USA</gco:CharacterString> </gmd:country> <gmd:electronicMailAddress> <gco:CharacterString>nsidc@nsidc.org</gco:CharacterString> </gmd:electronicMailAddress> </gmd:CI_Address> </gmd:address> <gmd:onlineResource> <gmd:CI_OnlineResource> <gmd:linkage> <gmd:URL>http://nsidc.org/daac/</gmd:URL> </gmd:linkage> </gmd:CI_OnlineResource> </gmd:onlineResource> <gmd:hoursOfService> <gco:CharacterString>9:00 A.M. to 5:00 P.M., U.S. Mountain Time, Monday through Friday, excluding U.S. holidays.</gco:CharacterString> </gmd:hoursOfService> <gmd:contactInstructions> <gco:CharacterString>Contact by e-mail first</gco:CharacterString> </gmd:contactInstructions> </gmd:CI_Contact> </gmd:contactInfo> <gmd:role> <gmd:CI_RoleCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#CI_RoleCode" codeListValue="pointOfContact">pointOfContact</gmd:CI_RoleCode> </gmd:role> </gmd:CI_ResponsibleParty> </gmd:contact> <gmd:dateStamp> <gco:Date>2015-10-15</gco:Date> </gmd:dateStamp> <gmd:metadataStandardName> <gco:CharacterString>ISO 19115-2 Geographic information - Metadata - Part 2: Extensions for imagery and gridded data</gco:CharacterString> </gmd:metadataStandardName> <gmd:metadataStandardVersion> <gco:CharacterString>ISO 19115-2:2009(E)</gco:CharacterString> </gmd:metadataStandardVersion> <gmd:identificationInfo> <gmd:MD_DataIdentification> <gmd:citation> <gmd:CI_Citation> <!-- ECS extracts the LongName from here --> <!-- UMM-C expects the ShortName to precede the LongName separated by a &gt; here --> <gmd:title> <gco:CharacterString>ATLAS/ICESat-2 L3A Land and Vegetation Height</gco:CharacterString> </gmd:title> <gmd:date> <gmd:CI_Date> <!-- ECS extracts the RevisionDate from here --> <gmd:date> <gco:Date>2016-06-09</gco:Date> </gmd:date> <gmd:dateType> <gmd:CI_DateTypeCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#CI_DateTypeCode" codeListValue="revision">revision</gmd:CI_DateTypeCode> </gmd:dateType> </gmd:CI_Date> </gmd:date> <!-- VersionID is expected to be here by the Base Reference Metadata Model document --> <gmd:edition> <gco:CharacterString>002</gco:CharacterString> </gmd:edition> <gmd:identifier> <gmd:MD_Identifier> <!-- ECS extracts the ShortName from here --> <gmd:code> <gco:CharacterString>ATL08</gco:CharacterString> </gmd:code> <gmd:description> <gco:CharacterString>The ECS Short Name</gco:CharacterString> </gmd:description> </gmd:MD_Identifier> </gmd:identifier> <gmd:identifier> <gmd:MD_Identifier> <!-- ECS extracts the VersionID from here --> <gmd:code> <gco:CharacterString>002</gco:CharacterString> </gmd:code> <gmd:description> <gco:CharacterString>The ECS Version ID</gco:CharacterString> </gmd:description> </gmd:MD_Identifier> </gmd:identifier> <gmd:identifier> <gmd:MD_Identifier> <!-- This field provides the Digital Object Identifier (DOI). --> <gmd:code> <gmx:Anchor xlink:actuate="onRequest" xlink:href="http://dx.doi.org/10.5067/ATLAS/ATL08.002">doi:10.5067/ATLAS/ATL08.002</gmx:Anchor> </gmd:code> <gmd:codeSpace> <gco:CharacterString>gov.nasa.esdis</gco:CharacterString> </gmd:codeSpace> <gmd:description> <gco:CharacterString>A Digital Object Identifier (DOI)</gco:CharacterString> </gmd:description> </gmd:MD_Identifier> </gmd:identifier> <gmd:citedResponsibleParty> <gmd:CI_ResponsibleParty> <gmd:organisationName> <gco:CharacterString>National Aeronautics and Space Administration (NASA)</gco:CharacterString> </gmd:organisationName> <gmd:role> <gmd:CI_RoleCode codeList="http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#CI_RoleCode" codeListValue="resourceProvider">resourceProvider</gmd:CI_RoleCode> </gmd:role> </gmd:CI_ResponsibleParty> </gmd:citedResponsibleParty> <gmd:citedResponsibleParty> <gmd:CI_ResponsibleParty> <!-- ECS expects ProcessingCenter to be here --> <gmd:organisationName> <gco:CharacterString>GSFC I-SIPS &gt; ICESat-2 Science Investigator-led Processing System</gco:CharacterString> </gmd:organisationName> <gmd:role> <gmd:CI_RoleCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#CI_RoleCode" codeListValue="originator">originator</gmd:CI_RoleCode> </gmd:role> </gmd:CI_ResponsibleParty> </gmd:citedResponsibleParty> <!-- ECS extracts the VersionDescription from here --> <gmd:otherCitationDetails> <gco:CharacterString>Initial version of the processing software</gco:CharacterString> </gmd:otherCitationDetails> </gmd:CI_Citation> </gmd:citation> <!-- ECS extracts the CollectionDescription from here --> <gmd:abstract> <gco:CharacterString>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.</gco:CharacterString> </gmd:abstract> <gmd:purpose> <gco:CharacterString>The purpose of ATL08 is to provide along-track land/canopy heights and associated statistics.</gco:CharacterString> </gmd:purpose> <gmd:credit> <gco:CharacterString>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.</gco:CharacterString> </gmd:credit> <gmd:status> <gmd:MD_ProgressCode codeList="http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#MD_ProgressCode" codeListValue="onGoing">onGoing</gmd:MD_ProgressCode> </gmd:status> <gmd:pointOfContact> <gmd:CI_ResponsibleParty> <!-- ECS expects ArchiveCenter to be here --> <gmd:organisationName> <gco:CharacterString>NSIDC DAAC &gt; NASA National Snow and Ice Data Center Distributed Active Archive Center</gco:CharacterString> </gmd:organisationName> <gmd:contactInfo xlink:href="#NSIDC_DAAC_CONTACT_ID"/> <gmd:role> <gmd:CI_RoleCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#CI_RoleCode" codeListValue="distributor">distributor</gmd:CI_RoleCode> </gmd:role> </gmd:CI_ResponsibleParty> </gmd:pointOfContact> <gmd:resourceFormat> <gmd:MD_Format> <gmd:name> <gco:CharacterString>HDF</gco:CharacterString> </gmd:name> <gmd:version> <gco:CharacterString>5</gco:CharacterString> </gmd:version> </gmd:MD_Format> </gmd:resourceFormat> <gmd:descriptiveKeywords> <gmd:MD_Keywords> <gmd:keyword> <gco:CharacterString>EARTH SCIENCE &gt; BIOSPHERE &gt; VEGETATION &gt; NONE &gt; NONE &gt; NONE &gt; NONE</gco:CharacterString> </gmd:keyword> <gmd:keyword> <gco:CharacterString>EARTH SCIENCE &gt; BIOSPHERE &gt; VEGETATION &gt; VEGETATION COVER &gt; NONE &gt; NONE &gt; NONE</gco:CharacterString> </gmd:keyword> <gmd:keyword> <gco:CharacterString>EARTH SCIENCE &gt; LAND SURFACE &gt; NONE &gt; NONE &gt; NONE &gt; NONE &gt; NONE</gco:CharacterString> </gmd:keyword> <gmd:keyword> <gco:CharacterString>EARTH SCIENCE &gt; LAND SURFACE &gt; TOPOGRAPHY &gt; SURFACE ROUGHNESS &gt; NONE &gt; NONE &gt; NONE</gco:CharacterString> </gmd:keyword> <gmd:keyword> <gco:CharacterString>EARTH SCIENCE &gt; LAND SURFACE &gt; TOPOGRAPHY &gt; TERRAIN ELEVATION &gt; NONE &gt; NONE &gt; NONE</gco:CharacterString> </gmd:keyword> <gmd:type> <gmd:MD_KeywordTypeCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#MD_KeywordTypeCode" codeListValue="theme">theme</gmd:MD_KeywordTypeCode> </gmd:type> <gmd:thesaurusName> <gmd:CI_Citation> <gmd:title> <gco:CharacterString>NASA/GCMD Science Keywords</gco:CharacterString> </gmd:title> <gmd:date gco:nilReason="unknown"/> <gmd:citedResponsibleParty> <gmd:CI_ResponsibleParty id="GCMD_USO_ID"> <gmd:organisationName> <gco:CharacterString>NASA Global Change Master Directory (GCMD) User Support Office</gco:CharacterString> </gmd:organisationName> <gmd:contactInfo> <gmd:CI_Contact> <gmd:phone gco:nilReason="missing"/> <gmd:address> <gmd:CI_Address> <gmd:deliveryPoint> <gco:CharacterString>NASA Global Change Master Directory, Goddard Space Flight Center</gco:CharacterString> </gmd:deliveryPoint> <gmd:city> <gco:CharacterString>Greenbelt</gco:CharacterString> </gmd:city> <gmd:administrativeArea> <gco:CharacterString>MD</gco:CharacterString> </gmd:administrativeArea> <gmd:postalCode> <gco:CharacterString>20771</gco:CharacterString> </gmd:postalCode> <gmd:country> <gco:CharacterString>USA</gco:CharacterString> </gmd:country> <gmd:electronicMailAddress> <gco:CharacterString>gcmduso@gcmd.gsfc.nasa.gov</gco:CharacterString> </gmd:electronicMailAddress> </gmd:CI_Address> </gmd:address> <gmd:onlineResource> <gmd:CI_OnlineResource> <gmd:linkage> <gmd:URL>http://gcmd.nasa.gov/</gmd:URL> </gmd:linkage> <gmd:protocol> <gco:CharacterString>http</gco:CharacterString> </gmd:protocol> <gmd:applicationProfile> <gco:CharacterString>web browser</gco:CharacterString> </gmd:applicationProfile> <gmd:name> <gco:CharacterString>NASA Global Change Master Directory (GCMD)</gco:CharacterString> </gmd:name> <gmd:description> <gco:CharacterString>Home Page</gco:CharacterString> </gmd:description> <gmd:function> <gmd:CI_OnLineFunctionCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#CI_OnLineFunctionCode" codeListValue="information">information</gmd:CI_OnLineFunctionCode> </gmd:function> </gmd:CI_OnlineResource> </gmd:onlineResource> <gmd:contactInstructions> <gco:CharacterString>http://gcmd.nasa.gov/MailComments/MailComments.jsf?rcpt=gcmduso</gco:CharacterString> </gmd:contactInstructions> </gmd:CI_Contact> </gmd:contactInfo> <gmd:role> <gmd:CI_RoleCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#CI_RoleCode" codeListValue="custodian">custodian</gmd:CI_RoleCode> </gmd:role> </gmd:CI_ResponsibleParty> </gmd:citedResponsibleParty> <gmd:citedResponsibleParty> <gmd:CI_ResponsibleParty id="GCMD_KEYWORDS_ID"> <gmd:organisationName> <gco:CharacterString>Global Change Master Directory (GCMD)</gco:CharacterString> </gmd:organisationName> <gmd:contactInfo> <gmd:CI_Contact> <gmd:phone gco:nilReason="missing"/> <gmd:address> <gmd:CI_Address> <gmd:deliveryPoint> <gco:CharacterString>NASA Global Change Master Directory, Goddard Space Flight Center</gco:CharacterString> </gmd:deliveryPoint> <gmd:city> <gco:CharacterString>Greenbelt</gco:CharacterString> </gmd:city> <gmd:administrativeArea> <gco:CharacterString>MD</gco:CharacterString> </gmd:administrativeArea> <gmd:postalCode> <gco:CharacterString>20771</gco:CharacterString> </gmd:postalCode> <gmd:country> <gco:CharacterString>USA</gco:CharacterString> </gmd:country> <gmd:electronicMailAddress> <gco:CharacterString>gcmduso@gcmd.gsfc.nasa.gov</gco:CharacterString> </gmd:electronicMailAddress> </gmd:CI_Address> </gmd:address> <gmd:onlineResource> <gmd:CI_OnlineResource> <gmd:linkage> <gmd:URL>http://gcmd.nasa.gov/Resources/valids/</gmd:URL> </gmd:linkage> <gmd:protocol> <gco:CharacterString>http</gco:CharacterString> </gmd:protocol> <gmd:applicationProfile> <gco:CharacterString>web browser</gco:CharacterString> </gmd:applicationProfile> <gmd:name> <gco:CharacterString>NASA Global Change Master Directory (GCMD) Keyword Page</gco:CharacterString> </gmd:name> <gmd:description> <gco:CharacterString>This page describes the NASA GCMD Keywords, how to reference those keywords and provides download instructions.</gco:CharacterString> </gmd:description> <gmd:function> <gmd:CI_OnLineFunctionCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#CI_OnLineFunctionCode" codeListValue="download">download</gmd:CI_OnLineFunctionCode> </gmd:function> </gmd:CI_OnlineResource> </gmd:onlineResource> <gmd:contactInstructions> <gco:CharacterString>http://gcmd.nasa.gov/MailComments/MailComments.jsf?rcpt=gcmduso</gco:CharacterString> </gmd:contactInstructions> </gmd:CI_Contact> </gmd:contactInfo> <gmd:role> <gmd:CI_RoleCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#CI_RoleCode" codeListValue="custodian">custodian</gmd:CI_RoleCode> </gmd:role> </gmd:CI_ResponsibleParty> </gmd:citedResponsibleParty> </gmd:CI_Citation> </gmd:thesaurusName> </gmd:MD_Keywords> </gmd:descriptiveKeywords> <gmd:descriptiveKeywords> <gmd:MD_Keywords> <gmd:keyword> <gco:CharacterString>GEOGRAPHIC REGION &gt; GLOBAL</gco:CharacterString> </gmd:keyword> <gmd:type> <gmd:MD_KeywordTypeCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#MD_KeywordTypeCode" codeListValue="place">place</gmd:MD_KeywordTypeCode> </gmd:type> <gmd:thesaurusName> <gmd:CI_Citation> <gmd:title> <gco:CharacterString>NASA/GCMD Location Keywords</gco:CharacterString> </gmd:title> <gmd:date gco:nilReason="unknown"/> <gmd:citedResponsibleParty xlink:href="#GCMD_USO_ID"/> <gmd:citedResponsibleParty xlink:href="#GCMD_KEYWORDS_ID"/> </gmd:CI_Citation> </gmd:thesaurusName> </gmd:MD_Keywords> </gmd:descriptiveKeywords> <gmd:descriptiveKeywords> <gmd:MD_Keywords> <gmd:keyword> <gco:CharacterString>NASA/NSIDC_DAAC &gt; NASA National Snow and Ice Data Center Distributed Active Archive Center</gco:CharacterString> </gmd:keyword> <gmd:type> <gmd:MD_KeywordTypeCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#MD_KeywordTypeCode" codeListValue="dataCenter">dataCenter</gmd:MD_KeywordTypeCode> </gmd:type> <gmd:thesaurusName> <gmd:CI_Citation> <gmd:title> <gco:CharacterString>NASA/GCMD Data Center Keywords</gco:CharacterString> </gmd:title> <gmd:date gco:nilReason="unknown"/> <gmd:citedResponsibleParty xlink:href="#GCMD_USO_ID"/> <gmd:citedResponsibleParty xlink:href="#GCMD_KEYWORDS_ID"/> </gmd:CI_Citation> </gmd:thesaurusName> </gmd:MD_Keywords> </gmd:descriptiveKeywords> <gmd:descriptiveKeywords> <gmd:MD_Keywords> <gmd:keyword> <gco:CharacterString>Earth Observation Satellites &gt; NASA Decadal Survey &gt; ICESAT-2 &gt; Ice, Cloud, and land Elevation Satellite-2</gco:CharacterString> </gmd:keyword> <gmd:type> <gmd:MD_KeywordTypeCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#MD_KeywordTypeCode" codeListValue="platform">platform</gmd:MD_KeywordTypeCode> </gmd:type> <gmd:thesaurusName> <gmd:CI_Citation> <gmd:title> <gco:CharacterString>NASA/GCMD Platform Keywords</gco:CharacterString> </gmd:title> <gmd:date gco:nilReason="unknown"/> <gmd:citedResponsibleParty xlink:href="#GCMD_USO_ID"/> <gmd:citedResponsibleParty xlink:href="#GCMD_KEYWORDS_ID"/> </gmd:CI_Citation> </gmd:thesaurusName> </gmd:MD_Keywords> </gmd:descriptiveKeywords> <gmd:descriptiveKeywords> <gmd:MD_Keywords> <gmd:keyword> <gco:CharacterString>Earth Remote Sensing Instruments &gt; Active Remote Sensing &gt; Altimeters &gt; Lidar/Laser Altimeters &gt; ATLAS &gt; Advanced Topographic Laser Altimeter System</gco:CharacterString> </gmd:keyword> <gmd:type> <gmd:MD_KeywordTypeCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#MD_KeywordTypeCode" codeListValue="instrument">instrument</gmd:MD_KeywordTypeCode> </gmd:type> <gmd:thesaurusName> <gmd:CI_Citation> <gmd:title> <gco:CharacterString>NASA/GCMD Instrument Keywords</gco:CharacterString> </gmd:title> <gmd:date gco:nilReason="unknown"/> <gmd:citedResponsibleParty xlink:href="#GCMD_USO_ID"/> <gmd:citedResponsibleParty xlink:href="#GCMD_KEYWORDS_ID"/> </gmd:CI_Citation> </gmd:thesaurusName> </gmd:MD_Keywords> </gmd:descriptiveKeywords> <gmd:resourceConstraints> <gmd:MD_Constraints> <gmd:useLimitation> <gco:CharacterString>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.</gco:CharacterString> </gmd:useLimitation> </gmd:MD_Constraints> </gmd:resourceConstraints> <gmd:language> <gco:CharacterString>eng</gco:CharacterString> </gmd:language> <gmd:topicCategory> <gmd:MD_TopicCategoryCode>geoscientificInformation</gmd:MD_TopicCategoryCode> </gmd:topicCategory> i <gmd:extent> <gmd:EX_Extent id="boundingExtent"> <gmd:description> <gco:CharacterString>SpatialCoverageType=HORIZONTAL, SpatialGranuleSpatialRepresentation=ORBIT, TemporalRangeType=Continuous Range, TimeType=UTC</gco:CharacterString> </gmd:description> <gmd:geographicElement> <gmd:EX_GeographicBoundingBox> <!-- ECS extracts WestBoundingCoordinate from here --> <gmd:westBoundLongitude> <gco:Decimal>-180.0</gco:Decimal> </gmd:westBoundLongitude> <!-- ECS extracts EastBoundingCoordinate from here --> <gmd:eastBoundLongitude> <gco:Decimal>180.0</gco:Decimal> </gmd:eastBoundLongitude> <!-- ECS extracts SouthBoundingCoordinate from here --> <gmd:southBoundLatitude> <gco:Decimal>-90.0</gco:Decimal> </gmd:southBoundLatitude> <!-- ECS extracts NorthBoundingCoordinate from here --> <gmd:northBoundLatitude> <gco:Decimal>90.0</gco:Decimal> </gmd:northBoundLatitude> </gmd:EX_GeographicBoundingBox> </gmd:geographicElement> <gmd:geographicElement> <gmd:EX_GeographicDescription> <gmd:geographicIdentifier> <gmd:MD_Identifier> <gmd:code> <gco:CharacterString>SwathWidth: 36.0 Period: 96.8 InclinationAngle: 92.0 NumberOfOrbits: 0.071428571 StartCircularLatitude: 0.0</gco:CharacterString> </gmd:code> <gmd:codeSpace> <gco:CharacterString>gov.nasa.esdis.umm.orbitparameters</gco:CharacterString> </gmd:codeSpace> <gmd:description> <gco:CharacterString>OrbitParameters</gco:CharacterString> </gmd:description> </gmd:MD_Identifier> </gmd:geographicIdentifier> </gmd:EX_GeographicDescription> </gmd:geographicElement> <gmd:temporalElement> <gmd:EX_TemporalExtent> <gmd:extent> <gml:TimePeriod gml:id="TimePeriod_ID_1"> <!-- ECS extracts RangeBeginningDate and RangeBeginningTime from here --> <gml:beginPosition>2005-01-01T00:00:00Z</gml:beginPosition> <!-- ECS extracts RangeEndingDate and RangeEndingTime from here --> <gml:endPosition>2020-12-31T23:59:59Z</gml:endPosition> </gml:TimePeriod> </gmd:extent> </gmd:EX_TemporalExtent> </gmd:temporalElement> </gmd:EX_Extent> </gmd:extent> <gmd:processingLevel> <gmd:MD_Identifier> <gmd:code> <gco:CharacterString>3A</gco:CharacterString> </gmd:code> <gmd:description gco:nilReason="missing"/> </gmd:MD_Identifier> </gmd:processingLevel> </gmd:MD_DataIdentification> </gmd:identificationInfo> <gmd:contentInfo> <gmd:MD_ImageDescription> <gmd:attributeDescription gco:nilReason="missing"/> <gmd:contentType gco:nilReason="missing"/> <gmd:processingLevelCode> <gmd:MD_Identifier> <gmd:code> <gco:CharacterString>3A</gco:CharacterString> </gmd:code> <gmd:description gco:nilReason="missing"/> </gmd:MD_Identifier> </gmd:processingLevelCode> </gmd:MD_ImageDescription> </gmd:contentInfo> <gmd:distributionInfo> <gmd:MD_Distribution> <gmd:distributionFormat> <gmd:MD_Format> <gmd:name> <gco:CharacterString>HDF</gco:CharacterString> </gmd:name> <gmd:version> <gco:CharacterString>5</gco:CharacterString> </gmd:version> </gmd:MD_Format> </gmd:distributionFormat> <gmd:distributor> <gmd:MD_Distributor> <gmd:distributorContact> <gmd:CI_ResponsibleParty> <gmd:organisationName> <gco:CharacterString>NSIDC DAAC &gt; NASA National Snow and Ice Data Center Distributed Active Archive Center</gco:CharacterString> </gmd:organisationName> <gmd:contactInfo xlink:href="#NSIDC_DAAC_CONTACT_ID"/> <gmd:role> <gmd:CI_RoleCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#CI_RoleCode" codeListValue="distributor">distributor</gmd:CI_RoleCode> </gmd:role> </gmd:CI_ResponsibleParty> </gmd:distributorContact> <gmd:distributorTransferOptions> <gmd:MD_DigitalTransferOptions> <gmd:onLine> <gmd:CI_OnlineResource> <gmd:linkage> <gmd:URL>http://nsidc.org/data/icesat2/data.html</gmd:URL> </gmd:linkage> <gmd:protocol> <gco:CharacterString>http</gco:CharacterString> </gmd:protocol> <gmd:description> <gco:CharacterString>Data Product Description Page</gco:CharacterString> </gmd:description> <gmd:function> <gmd:CI_OnLineFunctionCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#CI_OnLineFunctionCode" codeListValue="information">information</gmd:CI_OnLineFunctionCode> </gmd:function> </gmd:CI_OnlineResource> </gmd:onLine> <gmd:onLine> <gmd:CI_OnlineResource> <gmd:linkage> <gmd:URL>http://nsidc.org/data/icesat2/order.html</gmd:URL> </gmd:linkage> <gmd:protocol> <gco:CharacterString>http</gco:CharacterString> </gmd:protocol> <gmd:description> <gco:CharacterString>Data Product Order Page</gco:CharacterString> </gmd:description> <gmd:function> <gmd:CI_OnLineFunctionCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#CI_OnLineFunctionCode" codeListValue="order">order</gmd:CI_OnLineFunctionCode> </gmd:function> </gmd:CI_OnlineResource> </gmd:onLine> <gmd:onLine> <gmd:CI_OnlineResource> <gmd:linkage> <gmd:URL>http://dx.doi.org/10.5067/ATLAS/ATL08.002</gmd:URL> </gmd:linkage> <gmd:protocol> <gco:CharacterString>http</gco:CharacterString> </gmd:protocol> <gmd:description> <gco:CharacterString>Digital Object Identifier URL</gco:CharacterString> </gmd:description> <gmd:function> <gmd:CI_OnLineFunctionCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#CI_OnLineFunctionCode" codeListValue="information">information</gmd:CI_OnLineFunctionCode> </gmd:function> </gmd:CI_OnlineResource> </gmd:onLine> </gmd:MD_DigitalTransferOptions> </gmd:distributorTransferOptions> </gmd:MD_Distributor> </gmd:distributor> </gmd:MD_Distribution> </gmd:distributionInfo> <gmi:acquisitionInformation> <gmi:MI_AcquisitionInformation> <gmi:instrument> <eos:EOS_Instrument id="ATLAS_INSTRUMENT_ID"> <gmi:citation> <gmd:CI_Citation> <gmd:title> <gco:CharacterString>ATLAS &gt; Advanced Topographic Laser Altimeter System</gco:CharacterString> </gmd:title> <gmd:date gco:nilReason="unknown"/> </gmd:CI_Citation> </gmi:citation> <gmi:identifier> <gmd:MD_Identifier> <gmd:code> <gco:CharacterString>ATLAS</gco:CharacterString> </gmd:code> <gmd:description> <gco:CharacterString>Advanced Topographic Laser Altimeter System</gco:CharacterString> </gmd:description> </gmd:MD_Identifier> </gmi:identifier> <gmi:type> <gco:CharacterString>Laser Altimeter</gco:CharacterString> </gmi:type> <gmi:description> <gco:CharacterString>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.</gco:CharacterString> </gmi:description> <gmi:mountedOn xlink:href="#ICESAT_2_PLATFORM_ID"/> </eos:EOS_Instrument> </gmi:instrument> <gmi:operation> <!-- MI_Operation is expected to be here by the Base Reference Metadata Model document--> <gmi:MI_Operation> <gmi:description> <gco:CharacterString>ICESat-2 &gt; Ice, Cloud, and land Elevation Satellite-2</gco:CharacterString> </gmi:description> <gmi:citation> <gmd:CI_Citation> <gmd:title> <gco:CharacterString>ICESat-2 &gt; Ice, Cloud, and land Elevation Satellite-2</gco:CharacterString> </gmd:title> <gmd:date gco:nilReason="unknown"/> </gmd:CI_Citation> </gmi:citation> <gmi:identifier> <gmd:MD_Identifier> <gmd:code> <gco:CharacterString>ICESat-2</gco:CharacterString> </gmd:code> <gmd:description> <gco:CharacterString>Ice, Cloud, and land Elevation Satellite-2</gco:CharacterString> </gmd:description> </gmd:MD_Identifier> </gmi:identifier> <gmi:status> <gmd:MD_ProgressCode codeList="http://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#MD_ProgressCode" codeListValue="underDevelopment">underDevelopment</gmd:MD_ProgressCode> </gmi:status> <gmi:parentOperation gco:nilReason="inapplicable"/> <gmi:platform xlink:href="#ICESAT_2_PLATFORM_ID"/> </gmi:MI_Operation> </gmi:operation> <gmi:platform> <eos:EOS_Platform id="ICESAT_2_PLATFORM_ID"> <gmi:citation> <gmd:CI_Citation> <gmd:title> <gco:CharacterString>ICESat-2 &gt; Ice, Cloud, and land Elevation Satellite-2</gco:CharacterString> </gmd:title> <gmd:date gco:nilReason="unknown"/> </gmd:CI_Citation> </gmi:citation> <gmi:identifier> <gmd:MD_Identifier> <gmd:code> <gco:CharacterString>ICESat-2</gco:CharacterString> </gmd:code> <gmd:description> <gco:CharacterString>Ice, Cloud, and land Elevation Satellite-2</gco:CharacterString> </gmd:description> </gmd:MD_Identifier> </gmi:identifier> <gmi:description> <gco:CharacterString>Spacecraft</gco:CharacterString> </gmi:description> <gmi:instrument xlink:href="#ATLAS_INSTRUMENT_ID"/> </eos:EOS_Platform> </gmi:platform> </gmi:MI_AcquisitionInformation> </gmi:acquisitionInformation> </gmi:MI_Metadata> </gmd:seriesMetadata> </gmd:DS_Series> (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)
  • DataQuality(Type is Group)
    • attributes
      • scope: NOT_SET (Type is String)
    • CompletenessOmission(Type is Group)
      • attributes
        • evaluationMethodType: directInternal (Type is String)
        • measureDescription: TBD (Type is String)
        • nameOfMeasure: TBD (Type is String)
        • unitofMeasure: TBD (Type is String)
        • value: NOT_SET (Type is String)
    • DomainConsistency(Type is Group)
      • attributes
        • evaluationMethodType: directInternal (Type is String)
        • measureDescription: TBD (Type is String)
        • nameOfMeasure: TBD (Type is String)
        • unitofMeasure: TBD (Type is String)
        • value: NOT_SET (Type is String)
  • ProductSpecificationDocument(Type is Group)
    • attributes
      • characterSet: utf8 (Type is String)
      • edition: F (Type is String)
      • language: eng (Type is String)
      • publicationDate: 07/2019 (Type is String)
      • ShortName: ATL08_SDP (Type is String)
      • title: ICESat-2-SIPS-SPEC-4262 - ATLAS Science Algorithm Standard Data Product (SDP) Volume 7 (ATL08). (Type is String)
  • SeriesIdentification(Type is Group)
    • attributes
      • maintenanceAndUpdateFrequency: asNeeded (Type is String)
      • maintenanceDate: SET_BY_META (Type is String)
      • VersionID: 002 (Type is String)
      • identifier_product_DOI: 10.5067/ATLAS/ATL08.001 (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 (Type is String)
      • shortName: ATL08 (Type is String)
      • revisionDate: 2016-06-09 (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: 2019-08-22T21:07:29.000000Z (Type is String)
      • uuid: 58383667-e9b3-3639-a8de-168784ceb5e9 (Type is String)
      • fileName: ATL08_20181016124656_02730110_002_01.h5 (Type is String)
      • VersionID: 002 (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: -78.498235427544756 (Type is Float64)
      • eastBoundLongitude: -153.32549412458567 (Type is Float64)
      • southBoundLatitude: -78.804759009697463 (Type is Float64)
      • westBoundLongitude: -153.81953845733065 (Type is Float64)
      • rangeBeginningDateTime: 2018-10-16T12:54:26.671899Z (Type is String)
      • rangeEndingDateTime: 2018-10-16T12:54:31.250499Z (Type is String)
  • QADatasetIdentification(Type is Group)
    • attributes
      • 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)
      • creationDate: 2019-08-22T21:08:14.000000Z (Type is String)
      • fileName: ATL08_20181016124656_02730110_002_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_000081470.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)
        • fileName: dtu13_20180705_001_01.nc (Type is String)
        • shortName: ANC28 (Type is String)
        • uuid: 56f47040-a72e-3109-99c2-bc1658e6dda4 (Type is String)
        • version: 20180705 (Type is String)
    • ANC14(Type is Group)
      • attributes
        • description: Landsat Canopy Mask File (Type is String)
        • fileName: (Type is String)
        • shortName: ANC14 (Type is String)
        • uuid: (Type is String)
        • version: (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: atl08_template.h5 (Type is String)
        • shortName: ANC25-08 (Type is String)
        • uuid: 1d66a513-7f12-3239-bbb1-09e62031feec (Type is String)
        • version: 032 (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: Modis Land Cover Mask File (Type is String)
        • fileName: glcc_2012_20180226_001_global.h5 (Type is String)
        • shortName: ANC18 (Type is String)
        • uuid: 46e34ac9-892a-3a9d-ab7e-6a329e167a1a (Type is String)
        • version: 20180226 (Type is String)
    • ANC38-08(Type is Group)
      • attributes
        • description: ISO 19139 XML file containing DataSet-level metadata information. (Type is String)
        • fileName: ATL08.002.dataset.xml (Type is String)
        • shortName: ANC38-08 (Type is String)
        • uuid: 55e7a88e-6258-3bc1-844a-458ba3a595fc (Type is String)
        • version: 002 (Type is String)
    • ANC34(Type is Group)
      • attributes
        • description: Urban Mask File (Type is String)
        • fileName: SET_BY_PGE (Type is String)
        • shortName: SET_BY_PGE (Type is String)
        • uuid: SET_BY_PGE (Type is String)
        • version: SET_BY_PGE (Type is String)
    • ATL03(Type is Group)
      • attributes
        • description: ICESat-2 ATLAS L2A Global Geolocated Photon data products. (Type is String)
        • fileName: ATL03_20181016124656_02730110_002_01.h5 (Type is String)
        • shortName: ATL03 (Type is String)
        • uuid: 5afc3dc0-33ba-335b-b3bb-2cc34e7c4cd5 (Type is String)
        • version: 002 (Type is String)
        • start_cycle: 1 (Type is Int32)
        • end_cycle: 1 (Type is Int32)
        • start_orbit: 474 (Type is Int32)
        • end_orbit: 474 (Type is Int32)
        • start_rgt: 273 (Type is Int32)
        • end_rgt: 273 (Type is Int32)
        • start_region: 10 (Type is Int32)
        • end_region: 10 (Type is Int32)
        • start_geoseg: 1280110 (Type is Int32)
        • end_geoseg: 1443604 (Type is Int32)
    • ATL09(Type is Group)
      • attributes
        • description: ICESat-2 ATLAS L3A atmosphere data products. (Type is String)
        • fileName: ATL09_20181016114648_02730101_002_01.h5 (Type is String)
        • shortName: ATL09 (Type is String)
        • uuid: 0392edf6-cdc4-3c42-9ee7-12c7c38d14af (Type is String)
        • version: 002 (Type is String)
        • start_cycle: 1 (Type is Int32)
        • end_cycle: 1 (Type is Int32)
        • start_orbit: 474 (Type is Int32)
        • end_orbit: 474 (Type is Int32)
        • start_rgt: 273 (Type is Int32)
        • end_rgt: 273 (Type is Int32)
        • start_region: 1 (Type is Int32)
        • end_region: 14 (Type is Int32)
        • start_geoseg: 19 (Type is Int32)
        • end_geoseg: 2007126 (Type is Int32)
    • ANC06-01(Type is Group)
      • attributes
        • description: GMTED 7.5 arcsec Digital Elevation Model reformatted into HDF5 and re-referenced to the WGS-84 ellipsoid. (Type is String)
        • fileName: gmted75_20180705_001_01.h5 (Type is String)
        • shortName: ANC06-01 (Type is String)
        • uuid: a44debc8-29af-3744-860c-227b37a4da6f (Type is String)
        • version: 20180705 (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: atl08_metadata_template.h5 (Type is String)
        • shortName: ANC26-08 (Type is String)
        • uuid: f2d4b804-5f00-388c-80ba-9c45b0f9aecf (Type is String)
        • version: 032 (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: a5c65112-d05e-3263-83cd-a36f1a81acdf (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: ATL08.002.series.xml (Type is String)
        • shortName: ANC36-08 (Type is String)
        • uuid: 87849aa9-407f-3fec-9f8b-46f45b818b5e (Type is String)
        • version: 002 (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 2.2 (Type is String)
        • softwareDate: Jul 31 2019 (Type is String)
        • softwareTitle: Creates ATLAS HDF5 browse files (Type is String)
        • runTimeParameters: CTL_atlas_l3a_ld_000081470.ctl (Type is String)
        • stepDateTime: 2019-08-22T21:08:14.000000Z (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 4.2 (Type is String)
        • softwareDate: Jul 31 2019 (Type is String)
        • softwareTitle: Creates ATLAS XML metadata files (Type is String)
        • runTimeParameters: CTL_atlas_l3a_ld_000081470.ctl (Type is String)
        • stepDateTime: 2019-08-22T21:08:21.000000Z (Type is String)
    • PGE(Type is Group)
      • attributes
        • ATBDDate: 11/1/17 (Type is String)
        • ATBDTitle: ICESat-2-SIPS-SPEC-1608 - SIPs: Land, Vegetation, and Inland Water L5 Specification Document (Type is String)
        • ATBDVersion: 2017 November (Type is String)
        • documentation: ICESat-2-SIPS-SPEC-2331 - ATLAS Science Algorithm Software Design Description (SDD) Volume 12 (atlas_l3a_ld). Revision B. (Type is String)
        • documentDate: 12/1/17 (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 3.2 (Type is String)
        • softwareDate: Jul 31 2019 (Type is String)
        • softwareTitle: ASAS L3A Land PGE (Type is String)
        • runTimeParameters: CTL_atlas_l3a_ld_000081470.ctl (Type is String)
        • stepDateTime: 2019-08-22T21:07:29.000000Z (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 3.2 (Type is String)
        • softwareDate: Jul 31 2019 (Type is String)
        • softwareTitle: ATL08 QA Utility (Type is String)
        • runTimeParameters: CTL_atlas_l3a_ld_000081470.ctl (Type is String)
        • stepDateTime: 2019-08-22T21:08:14.000000Z (Type is String)
gt1r(Type is Group)
  • attributes
    • Description: Each group contains the segments for one Ground Track. As ICESat-2 orbits the earth, sequential transmit pulses illuminate six ground tracks on the surface of the earth. The track width is approximately 14m. Each ground track is numbered, according to the laser spot number that generates a given ground track. Ground tracks are numbered from the left to the right in the direction of spacecraft travel as: 1L, 1R in the left-most pair of beams; 2L, 2R for the center pair of beams; and 3L, 3R for the right-most pair of beams. (Type is String)
    • atlas_pce: pce3 (Type is String)
    • atlas_beam_type: strong (Type is String)
    • groundtrack_id: gt1r (Type is String)
    • atmosphere_profile: profile_1 (Type is String)
    • atlas_spot_number: 5 (Type is String)
    • sc_orientation: Forward (Type is String)
  • signal_photons(Type is Group)
    • attributes
      • Description: Contains parameters related to individual photons. (Type is String)
      • data_rate: Data are stored at the signal-photon classification rate. (Type is String)
    • delta_time[ 0..69380] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • long_name: delta time (Type is String)
        • standard_name: time (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)
        • source: ATL03 (Type is String)
    • classed_pc_indx[ 0..69380] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: indicies of classed photons (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)
        • source: Retained from prior a_alt_science_ph packet (Type is String)
        • coordinates: delta_time (Type is String)
    • classed_pc_flag[ 0..69380] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: photon land atbd classification (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)
        • source: Land ATBD section 4.10 (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)
    • d_flag[ 0..69380] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: dragann flag (Type is String)
        • description: Flag indicating the labeling of DRAGANN noise filtering for a given photon. (Type is String)
        • source: Land ATBD section 2.3.5 (Type is String)
        • coordinates: delta_time (Type is String)
        • flag_meanings: noise signal (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • ph_segment_id[ 0..69380] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: segment id of photon (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)
        • source: Retained from prior a_alt_science_ph packet (Type is String)
        • coordinates: delta_time (Type is String)
  • land_segments(Type is Group)
    • attributes
      • 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)
    • longitude[ 0..217] (Type is Float32)
      • attributes
        • units: degrees (Type is String)
        • long_name: longitude (Type is String)
        • standard_name: longitude (Type is String)
        • description: Longitude of the center-most signal photon within each segment. (Type is String)
        • source: Land ATBD section 2.4 (Type is String)
        • coordinates: delta_time latitude (Type is String)
        • valid_min: -180. (Type is Float32)
        • valid_max: 180. (Type is Float32)
    • latitude[ 0..217] (Type is Float32)
      • attributes
        • units: degrees (Type is String)
        • long_name: latitude (Type is String)
        • standard_name: latitude (Type is String)
        • description: Latitude of the center-most signal photon within each segment. (Type is String)
        • source: Land ATBD section 2.4 (Type is String)
        • coordinates: delta_time longitude (Type is String)
        • valid_min: -90. (Type is Float32)
        • valid_max: 90. (Type is Float32)
    • delta_time[ 0..217] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • long_name: mean_pass_time (Type is String)
        • standard_name: time (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)
        • source: Land ATBD section 2.4 (Type is String)
        • coordinates: latitude longitude (Type is String)
    • dem_flag[ 0..217] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: dem source flag (Type is String)
        • description: Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=GMTED, 3=MSS, 4=Antarctic. (Type is String)
        • source: Atmosphere ATBD (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: none arctic gmted mss antarctic (Type is String)
        • flag_values: 0, 1, 2, 3, 4 (Type is Int8)
        • valid_min: 0 (Type is Int8)
        • valid_max: 4 (Type is Int8)
    • msw_flag[ 0..217] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • long_name: multiple scattering warning flag (Type is String)
        • description: Multiple Scattering warning flag. The multiple scattering warning flag (ATL09 parameter msw_flag) has values from -1 to 5 where zero means no multiple scattering and 5 the greatest. 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 -1 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 -1 to occur only during daylight. (Type is String)
        • source: ATL09 (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: -1, 0, 1, 2, 3, 4, 5 (Type is Int8)
    • cloud_flag_atm[ 0..217] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • long_name: cloud flag atm (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)
        • source: ATL09 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • valid_min: 0 (Type is Int8)
        • valid_max: 10 (Type is Int8)
    • snr[ 0..217] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • long_name: signal to noise ratio (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)
        • source: ATBD section 2.5.14 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_across[ 0..217] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: sigma atlas y (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • layer_flag[ 0..217] (Type is Int8)
      • attributes
        • contentType: modelResult (Type is String)
        • long_name: consolidated cloud flag (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)
        • source: ATL09 (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[ 0..217] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • long_name: segment snowcover (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)
        • source: ATBD section 4.2.16 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: ice_free_water snow_free_land snow ice (Type is String)
        • flag_values: 0, 1, 2, 3 (Type is Int8)
        • valid_min: 0 (Type is Int8)
        • valid_max: 3 (Type is Int8)
    • beam_azimuth[ 0..217] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: radians (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: beam azimuth (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • solar_azimuth[ 0..217] (Type is Float32)
      • attributes
        • units: degrees_east (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: solar azimuth (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)
        • source: ATL03g ATBD (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • psf_flag[ 0..217] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: point spread function flag (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)
        • source: Land/Veg ATBD (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: below_threshold above_threshold (Type is String)
        • flag_values: 0, 1 (Type is Int8)
        • valid_min: 0 (Type is Int8)
        • valid_max: 1 (Type is Int8)
    • segment_watermask[ 0..217] (Type is Int32)
      • attributes
        • _FillValue: 255 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: segment watermask (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)
        • source: ATBD section 2.4.15 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: no_water water (Type is String)
        • flag_values: 0, 1 (Type is Int32)
        • valid_min: 0 (Type is Int32)
        • valid_max: 1 (Type is Int32)
    • delta_time_end[ 0..217] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: delta time end (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)
        • source: Derived (gps_seconds-gps_sec_offset) (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • segment_id_end[ 0..217] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: end geolocation segment bin (Type is String)
        • description: Geolocation segment number of the last photon in the land segment. (Type is String)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • surf_type[ 0..217] [ 0..4] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: surface type (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)
        • source: ATL03 ATBD, Section 4 (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)
        • valid_min: 0 (Type is Int8)
        • valid_max: 1 (Type is Int8)
    • brightness_flag[ 0..217] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • long_name: brightness flag (Type is String)
        • description: Flag indicating that the ground surface is bright (e.g. snow-covered or other bright surfaces) (Type is String)
        • source: Land ATBD section 2.4.21 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: not_bright_surface bright_surface (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • segment_landcover[ 0..217] (Type is Int32)
      • attributes
        • _FillValue: 255 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: segment landcover (Type is String)
        • description: IGBP Land Cover Surface type classification as reference from MODIS Land Cover(ANC18) at the 0.5 arcsecond resolution. (Type is String)
        • source: ATBD section 2.4.14 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: Water Evergreen_Needleleaf_Forest Evergreen_Broadleaf_Forest Deciduous_Needleleaf_Forest Deciduous_Broadleaf_Forest Mixed_Forest Closed_Shrublands Open_Shrubland Woody_Savanna Savanna Grassland Wetland Croplands Urban Crop_Mosaic Permanent_Snow Barren (Type is String)
        • flag_values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 (Type is Int32)
        • valid_min: 0 (Type is Int32)
        • valid_max: 16 (Type is Int32)
    • ph_removal_flag[ 0..217] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: ph removal flag (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)
        • source: ATBD section 4.13 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: below_threshold above_threshold (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • asr[ 0..217] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • long_name: apparent surface reflectance (Type is String)
        • description: Apparent surface reflectance (Type is String)
        • source: ATL09 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_atlas_land[ 0..217] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: sigma atlas land (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. (Type is String)
        • source: Land ATBD section 2.5.13 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • segment_id_beg[ 0..217] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: begin geolocation segment bin (Type is String)
        • description: Geolocation segment number of the first photon in the land segment. (Type is String)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_along[ 0..217] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: sigma atlas x (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • dem_h[ 0..217] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: meters (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: dem height (Type is String)
        • description: Best available DEM (in priority of Arctic/Antarctic/GMTED/MSS) value at the geolocation point. Height is in meters above the WGS84 Ellipsoid. (Type is String)
        • source: GIMP, GMTED,MSS (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • beam_coelev[ 0..217] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: radians (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: beam co-elevation (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_topo[ 0..217] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: sigma atlas topo (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)
        • source: Land ATBD section 2.5.12 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • night_flag[ 0..217] (Type is Int32)
      • attributes
        • _FillValue: 2147483647 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: night flag (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)
        • source: Land ATBD section 2.4.8 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: day night (Type is String)
        • flag_values: 0, 1 (Type is Int32)
    • delta_time_beg[ 0..217] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: delta time begin (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)
        • source: Derived (gps_seconds-gps_sec_offset) (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_h[ 0..217] (Type is Float32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • long_name: height uncertainty (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
    • last_seg_extend[ 0..217] (Type is Float32)
      • attributes
        • units: kilometers (Type is String)
        • long_name: last segment extended (Type is String)
        • standard_name: last_seg_extend (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)
        • source: Land ATBD 13March2019, Section 2.4.20 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • atlas_pa[ 0..217] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: radians (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: atlas pointing angle (Type is String)
        • description: Off nadir pointing angle (in radians) of the satellite to increase spatial sampling in the non-polar regions. ATLAS_PA =90degs-beam_coelev. (Type is String)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • ph_ndx_beg[ 0..217] (Type is Int64)
      • attributes
        • units: 1 (Type is String)
        • long_name: photon index begin (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)
        • source: Derived (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • solar_elevation[ 0..217] (Type is Float32)
      • attributes
        • units: degrees (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: solar elevation (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)
        • source: ATL03g ATBD (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • rgt[ 0..217] (Type is Int16)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: reference ground track (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)
        • source: Operations (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • valid_min: 1 (Type is Int16)
        • valid_max: 1387 (Type is Int16)
    • cloud_fold_flag[ 0..217] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • contentType: modelResult (Type is String)
        • long_name: cloud folding flag (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)
        • source: ATL09 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: no_folding goes5_indicates profile_indicates both_indicate (Type is String)
        • flag_values: 0, 1, 2, 3 (Type is Int8)
        • valid_min: 0 (Type is Int8)
        • valid_max: 3 (Type is Int8)
    • n_seg_ph[ 0..217] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • long_name: number of photons (Type is String)
        • description: Number of photons within each land segment. (Type is String)
        • source: Derived (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • terrain_flg[ 0..217] (Type is Int32)
      • attributes
        • _FillValue: 2147483647 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: terrain flag (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)
        • source: Land ATBD section 2.4.8 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: below_threshold above_threshold (Type is String)
        • flag_values: 0, 1 (Type is Int32)
    • urban_flag[ 0..217] (Type is Int32)
      • attributes
        • _FillValue: 2147483647 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: segment urban flag (Type is String)
        • description: The urban flag indicates that a segment is likely located over an urban area. (Type is String)
        • source: Land ATBD section 2.4.17 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: not_urban urban (Type is String)
        • flag_values: 0, 1 (Type is Int32)
    • dem_removal_flag[ 0..217] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: dem removal flag (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)
        • source: ATBD section 2.4.11 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: below_threshold above_threshold (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • h_dif_ref[ 0..217] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: meters (Type is String)
        • long_name: h dif from reference (Type is String)
        • description: Difference between h_te_median and ref_DEM (Type is String)
        • source: Land ATBD section 2.4 (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[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: height canopy (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)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_rh_conf[ 0..217] (Type is Int8)
        • attributes
          • units: 1 (Type is String)
          • contentType: modelResult (Type is String)
          • long_name: canopy relative height confidence (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)
          • source: Land/Veg ATBD 13March2019, Section 2.2.21 (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)
          • valid_min: 0 (Type is Int8)
          • valid_max: 2 (Type is Int8)
      • h_median_canopy_abs[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute segment median canopy height (Type is String)
          • description: The median of individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.6 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_min_canopy[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: minimum canopy height (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)
          • source: Land ATBD section 2.2.10 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_mean_canopy_abs[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute mean canopy height (Type is String)
          • description: Mean of the individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.4 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_median_canopy[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: median canopy height (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)
          • source: Land ATBD section 2.2.8 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_canopy_abs[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute segment canopy height (Type is String)
          • description: The 98% height of all the absolute individual canopy heights referenced above the WGS84 ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.2 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • toc_roughness[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: top of canopy roughness (Type is String)
          • description: Standard deviation of the relative heights of all photons classified as top of canopy within the segment (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_min_canopy_abs[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute minimum canopy height (Type is String)
          • description: The minimum of absolute individual canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.9 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_dif_canopy[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: canopy diff to median height (Type is String)
          • description: Difference between h_canopy and h_median_canopy (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_canopy_quad[ 0..217] (Type is Float32)
        • attributes
          • long_name: canopy quadratic mean (Type is String)
          • description: The quadratic mean height of individual classified relative canopy photon heights above the estimated terrain surface. (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
      • n_ca_photons[ 0..217] (Type is Int32)
        • attributes
          • units: 1 (Type is String)
          • long_name: number canopy photons (Type is String)
          • description: The number of photons classified as canopy within the segment. (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • centroid_height[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: centroid height (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)
          • source: Land ATBD section 2.2.22 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_h_metrics_abs[ 0..217] [ 0..8] (Type is Float32)
        • attributes
          • long_name: canopy absolute height metrics (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: 25,50,60,70,75,80,85,90,95%. (Type is String)
          • source: Land ATBD section 2.2.3 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
      • landsat_perc[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: 1 (Type is String)
          • long_name: landsat percentage canopy (Type is String)
          • description: Average percentage value of the valid (value <= 100) Landsat Tree Cover Continuous Fields product for each 100 m segment (Type is String)
          • source: Land ATBD section 2.2.24 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_mean_canopy[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: mean canopy height (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)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_h_metrics[ 0..217] [ 0..8] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: canopy height metrics (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: 25,50,60,70,75,80,85,90,95%. (Type is String)
          • source: Land ATBD section 2.2.3 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • n_toc_photons[ 0..217] (Type is Int32)
        • attributes
          • units: 1 (Type is String)
          • long_name: number top of canopy photons (Type is String)
          • description: The number of photons classified as top of canopy within the segment. (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_flag[ 0..217] (Type is Int32)
        • attributes
          • _FillValue: 2147483647 (Type is Int32)
          • units: 1 (Type is String)
          • long_name: canopy flag (Type is String)
          • description: Flag indicating that canopy was detected using the Landsat Tree Cover Continuous Fields data product. If percent of canopy cover along the L-km segment is greater than 5%, then canopy is assumed to be present; else, no canopy is assumed present. (Type is String)
          • source: Land ATBD section 2.2.22 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • flag_meanings: no_canopy_present canopy_present (Type is String)
          • flag_values: 0, 1 (Type is Int32)
      • landsat_flag[ 0..217] (Type is Int32)
        • attributes
          • _FillValue: 2147483647 (Type is Int32)
          • units: 1 (Type is String)
          • long_name: landsat flag (Type is String)
          • description: Flag indicating that more than 50% of the Landsat Continuous Cover product have values > 100 for the L-Km segment. Canopy is assumed present along the L-km segment if landsat_flag is 1. (Type is String)
          • source: Land ATBD section 2.2.25 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • flag_meanings: canopy_not_assumed_present canopy_assumed_present (Type is String)
          • flag_values: 0, 1 (Type is Int32)
      • h_max_canopy_abs[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute maximum canopy height (Type is String)
          • description: Maximum of individual absolute canopy heights within segment referenced above the WGS84 ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_canopy_uncertainty[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: segment canopy height uncertainty (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 in the Land ATBD (Type is String)
          • source: Land ATBD section 1.5 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_openness[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: 1 (Type is String)
          • long_name: canopy openness (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)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_max_canopy[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: maximum canopy height (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)
          • source: Land ATBD section 2.2.12 (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[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: uncertainty of h_te_mean (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 (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_mean[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: mean terrain height (Type is String)
          • description: The mean of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_min[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: minimum terrain height (Type is String)
          • description: The minimum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_interp[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: interpolated terrain surface height (Type is String)
          • description: Interpolated terrain surface height above the WGS84 Ellipsoid at the midpoint of the segment. (Type is String)
          • source: Land ATBD section 4.9 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_max[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: maximum terrain height (Type is String)
          • description: The maximum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_skew[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: skew of terrain heights (Type is String)
          • description: The skewness of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_median[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: median terrain height (Type is String)
          • description: The median of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_best_fit[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: segment terrain height best fit (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)
          • source: Land ATBD section 2.1.15 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_std[ 0..217] (Type is Float32)
        • attributes
          • long_name: segment terrain roughness (Type is String)
          • description: The standard deviation of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
      • terrain_slope[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: 1 (Type is String)
          • long_name: segment terrain slope (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)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • n_te_photons[ 0..217] (Type is Int32)
        • attributes
          • units: 1 (Type is String)
          • long_name: number of ground photons (Type is String)
          • description: The number of the photons classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_mode[ 0..217] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: mode of terrain heights (Type is String)
          • description: The mode of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
gt2r(Type is Group)
  • attributes
    • Description: Each group contains the segments for one Ground Track. As ICESat-2 orbits the earth, sequential transmit pulses illuminate six ground tracks on the surface of the earth. The track width is approximately 14m. Each ground track is numbered, according to the laser spot number that generates a given ground track. Ground tracks are numbered from the left to the right in the direction of spacecraft travel as: 1L, 1R in the left-most pair of beams; 2L, 2R for the center pair of beams; and 3L, 3R for the right-most pair of beams. (Type is String)
    • atlas_pce: pce2 (Type is String)
    • atlas_beam_type: strong (Type is String)
    • groundtrack_id: gt2r (Type is String)
    • atmosphere_profile: profile_2 (Type is String)
    • atlas_spot_number: 3 (Type is String)
    • sc_orientation: Forward (Type is String)
  • signal_photons(Type is Group)
    • attributes
      • Description: Contains parameters related to individual photons. (Type is String)
      • data_rate: Data are stored at the signal-photon classification rate. (Type is String)
    • delta_time[ 0..14712] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • long_name: delta time (Type is String)
        • standard_name: time (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)
        • source: ATL03 (Type is String)
    • classed_pc_indx[ 0..14712] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: indicies of classed photons (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)
        • source: Retained from prior a_alt_science_ph packet (Type is String)
        • coordinates: delta_time (Type is String)
    • classed_pc_flag[ 0..14712] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: photon land atbd classification (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)
        • source: Land ATBD section 4.10 (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)
    • d_flag[ 0..14712] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: dragann flag (Type is String)
        • description: Flag indicating the labeling of DRAGANN noise filtering for a given photon. (Type is String)
        • source: Land ATBD section 2.3.5 (Type is String)
        • coordinates: delta_time (Type is String)
        • flag_meanings: noise signal (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • ph_segment_id[ 0..14712] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: segment id of photon (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)
        • source: Retained from prior a_alt_science_ph packet (Type is String)
        • coordinates: delta_time (Type is String)
  • land_segments(Type is Group)
    • attributes
      • 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)
    • longitude[ 0..77] (Type is Float32)
      • attributes
        • units: degrees (Type is String)
        • long_name: longitude (Type is String)
        • standard_name: longitude (Type is String)
        • description: Longitude of the center-most signal photon within each segment. (Type is String)
        • source: Land ATBD section 2.4 (Type is String)
        • coordinates: delta_time latitude (Type is String)
        • valid_min: -180. (Type is Float32)
        • valid_max: 180. (Type is Float32)
    • latitude[ 0..77] (Type is Float32)
      • attributes
        • units: degrees (Type is String)
        • long_name: latitude (Type is String)
        • standard_name: latitude (Type is String)
        • description: Latitude of the center-most signal photon within each segment. (Type is String)
        • source: Land ATBD section 2.4 (Type is String)
        • coordinates: delta_time longitude (Type is String)
        • valid_min: -90. (Type is Float32)
        • valid_max: 90. (Type is Float32)
    • delta_time[ 0..77] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • long_name: mean_pass_time (Type is String)
        • standard_name: time (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)
        • source: Land ATBD section 2.4 (Type is String)
        • coordinates: latitude longitude (Type is String)
    • dem_flag[ 0..77] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: dem source flag (Type is String)
        • description: Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=GMTED, 3=MSS, 4=Antarctic. (Type is String)
        • source: Atmosphere ATBD (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: none arctic gmted mss antarctic (Type is String)
        • flag_values: 0, 1, 2, 3, 4 (Type is Int8)
        • valid_min: 0 (Type is Int8)
        • valid_max: 4 (Type is Int8)
    • msw_flag[ 0..77] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • long_name: multiple scattering warning flag (Type is String)
        • description: Multiple Scattering warning flag. The multiple scattering warning flag (ATL09 parameter msw_flag) has values from -1 to 5 where zero means no multiple scattering and 5 the greatest. 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 -1 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 -1 to occur only during daylight. (Type is String)
        • source: ATL09 (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: -1, 0, 1, 2, 3, 4, 5 (Type is Int8)
    • cloud_flag_atm[ 0..77] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • long_name: cloud flag atm (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)
        • source: ATL09 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • valid_min: 0 (Type is Int8)
        • valid_max: 10 (Type is Int8)
    • snr[ 0..77] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • long_name: signal to noise ratio (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)
        • source: ATBD section 2.5.14 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_across[ 0..77] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: sigma atlas y (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • layer_flag[ 0..77] (Type is Int8)
      • attributes
        • contentType: modelResult (Type is String)
        • long_name: consolidated cloud flag (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)
        • source: ATL09 (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[ 0..77] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • long_name: segment snowcover (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)
        • source: ATBD section 4.2.16 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: ice_free_water snow_free_land snow ice (Type is String)
        • flag_values: 0, 1, 2, 3 (Type is Int8)
        • valid_min: 0 (Type is Int8)
        • valid_max: 3 (Type is Int8)
    • beam_azimuth[ 0..77] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: radians (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: beam azimuth (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • solar_azimuth[ 0..77] (Type is Float32)
      • attributes
        • units: degrees_east (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: solar azimuth (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)
        • source: ATL03g ATBD (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • psf_flag[ 0..77] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: point spread function flag (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)
        • source: Land/Veg ATBD (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: below_threshold above_threshold (Type is String)
        • flag_values: 0, 1 (Type is Int8)
        • valid_min: 0 (Type is Int8)
        • valid_max: 1 (Type is Int8)
    • segment_watermask[ 0..77] (Type is Int32)
      • attributes
        • _FillValue: 255 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: segment watermask (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)
        • source: ATBD section 2.4.15 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: no_water water (Type is String)
        • flag_values: 0, 1 (Type is Int32)
        • valid_min: 0 (Type is Int32)
        • valid_max: 1 (Type is Int32)
    • delta_time_end[ 0..77] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: delta time end (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)
        • source: Derived (gps_seconds-gps_sec_offset) (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • segment_id_end[ 0..77] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: end geolocation segment bin (Type is String)
        • description: Geolocation segment number of the last photon in the land segment. (Type is String)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • surf_type[ 0..77] [ 0..4] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: surface type (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)
        • source: ATL03 ATBD, Section 4 (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)
        • valid_min: 0 (Type is Int8)
        • valid_max: 1 (Type is Int8)
    • brightness_flag[ 0..77] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • long_name: brightness flag (Type is String)
        • description: Flag indicating that the ground surface is bright (e.g. snow-covered or other bright surfaces) (Type is String)
        • source: Land ATBD section 2.4.21 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: not_bright_surface bright_surface (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • segment_landcover[ 0..77] (Type is Int32)
      • attributes
        • _FillValue: 255 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: segment landcover (Type is String)
        • description: IGBP Land Cover Surface type classification as reference from MODIS Land Cover(ANC18) at the 0.5 arcsecond resolution. (Type is String)
        • source: ATBD section 2.4.14 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: Water Evergreen_Needleleaf_Forest Evergreen_Broadleaf_Forest Deciduous_Needleleaf_Forest Deciduous_Broadleaf_Forest Mixed_Forest Closed_Shrublands Open_Shrubland Woody_Savanna Savanna Grassland Wetland Croplands Urban Crop_Mosaic Permanent_Snow Barren (Type is String)
        • flag_values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 (Type is Int32)
        • valid_min: 0 (Type is Int32)
        • valid_max: 16 (Type is Int32)
    • ph_removal_flag[ 0..77] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: ph removal flag (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)
        • source: ATBD section 4.13 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: below_threshold above_threshold (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • asr[ 0..77] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • long_name: apparent surface reflectance (Type is String)
        • description: Apparent surface reflectance (Type is String)
        • source: ATL09 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_atlas_land[ 0..77] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: sigma atlas land (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. (Type is String)
        • source: Land ATBD section 2.5.13 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • segment_id_beg[ 0..77] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: begin geolocation segment bin (Type is String)
        • description: Geolocation segment number of the first photon in the land segment. (Type is String)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_along[ 0..77] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: sigma atlas x (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • dem_h[ 0..77] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: meters (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: dem height (Type is String)
        • description: Best available DEM (in priority of Arctic/Antarctic/GMTED/MSS) value at the geolocation point. Height is in meters above the WGS84 Ellipsoid. (Type is String)
        • source: GIMP, GMTED,MSS (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • beam_coelev[ 0..77] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: radians (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: beam co-elevation (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_topo[ 0..77] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: sigma atlas topo (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)
        • source: Land ATBD section 2.5.12 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • night_flag[ 0..77] (Type is Int32)
      • attributes
        • _FillValue: 2147483647 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: night flag (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)
        • source: Land ATBD section 2.4.8 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: day night (Type is String)
        • flag_values: 0, 1 (Type is Int32)
    • delta_time_beg[ 0..77] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: delta time begin (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)
        • source: Derived (gps_seconds-gps_sec_offset) (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_h[ 0..77] (Type is Float32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • long_name: height uncertainty (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
    • last_seg_extend[ 0..77] (Type is Float32)
      • attributes
        • units: kilometers (Type is String)
        • long_name: last segment extended (Type is String)
        • standard_name: last_seg_extend (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)
        • source: Land ATBD 13March2019, Section 2.4.20 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • atlas_pa[ 0..77] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: radians (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: atlas pointing angle (Type is String)
        • description: Off nadir pointing angle (in radians) of the satellite to increase spatial sampling in the non-polar regions. ATLAS_PA =90degs-beam_coelev. (Type is String)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • ph_ndx_beg[ 0..77] (Type is Int64)
      • attributes
        • units: 1 (Type is String)
        • long_name: photon index begin (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)
        • source: Derived (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • solar_elevation[ 0..77] (Type is Float32)
      • attributes
        • units: degrees (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: solar elevation (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)
        • source: ATL03g ATBD (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • rgt[ 0..77] (Type is Int16)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: reference ground track (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)
        • source: Operations (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • valid_min: 1 (Type is Int16)
        • valid_max: 1387 (Type is Int16)
    • cloud_fold_flag[ 0..77] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • contentType: modelResult (Type is String)
        • long_name: cloud folding flag (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)
        • source: ATL09 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: no_folding goes5_indicates profile_indicates both_indicate (Type is String)
        • flag_values: 0, 1, 2, 3 (Type is Int8)
        • valid_min: 0 (Type is Int8)
        • valid_max: 3 (Type is Int8)
    • n_seg_ph[ 0..77] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • long_name: number of photons (Type is String)
        • description: Number of photons within each land segment. (Type is String)
        • source: Derived (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • terrain_flg[ 0..77] (Type is Int32)
      • attributes
        • _FillValue: 2147483647 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: terrain flag (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)
        • source: Land ATBD section 2.4.8 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: below_threshold above_threshold (Type is String)
        • flag_values: 0, 1 (Type is Int32)
    • urban_flag[ 0..77] (Type is Int32)
      • attributes
        • _FillValue: 2147483647 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: segment urban flag (Type is String)
        • description: The urban flag indicates that a segment is likely located over an urban area. (Type is String)
        • source: Land ATBD section 2.4.17 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: not_urban urban (Type is String)
        • flag_values: 0, 1 (Type is Int32)
    • dem_removal_flag[ 0..77] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: dem removal flag (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)
        • source: ATBD section 2.4.11 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: below_threshold above_threshold (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • h_dif_ref[ 0..77] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: meters (Type is String)
        • long_name: h dif from reference (Type is String)
        • description: Difference between h_te_median and ref_DEM (Type is String)
        • source: Land ATBD section 2.4 (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[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: height canopy (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)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_rh_conf[ 0..77] (Type is Int8)
        • attributes
          • units: 1 (Type is String)
          • contentType: modelResult (Type is String)
          • long_name: canopy relative height confidence (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)
          • source: Land/Veg ATBD 13March2019, Section 2.2.21 (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)
          • valid_min: 0 (Type is Int8)
          • valid_max: 2 (Type is Int8)
      • h_median_canopy_abs[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute segment median canopy height (Type is String)
          • description: The median of individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.6 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_min_canopy[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: minimum canopy height (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)
          • source: Land ATBD section 2.2.10 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_mean_canopy_abs[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute mean canopy height (Type is String)
          • description: Mean of the individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.4 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_median_canopy[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: median canopy height (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)
          • source: Land ATBD section 2.2.8 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_canopy_abs[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute segment canopy height (Type is String)
          • description: The 98% height of all the absolute individual canopy heights referenced above the WGS84 ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.2 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • toc_roughness[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: top of canopy roughness (Type is String)
          • description: Standard deviation of the relative heights of all photons classified as top of canopy within the segment (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_min_canopy_abs[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute minimum canopy height (Type is String)
          • description: The minimum of absolute individual canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.9 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_dif_canopy[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: canopy diff to median height (Type is String)
          • description: Difference between h_canopy and h_median_canopy (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_canopy_quad[ 0..77] (Type is Float32)
        • attributes
          • long_name: canopy quadratic mean (Type is String)
          • description: The quadratic mean height of individual classified relative canopy photon heights above the estimated terrain surface. (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
      • n_ca_photons[ 0..77] (Type is Int32)
        • attributes
          • units: 1 (Type is String)
          • long_name: number canopy photons (Type is String)
          • description: The number of photons classified as canopy within the segment. (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • centroid_height[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: centroid height (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)
          • source: Land ATBD section 2.2.22 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_h_metrics_abs[ 0..77] [ 0..8] (Type is Float32)
        • attributes
          • long_name: canopy absolute height metrics (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: 25,50,60,70,75,80,85,90,95%. (Type is String)
          • source: Land ATBD section 2.2.3 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
      • landsat_perc[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: 1 (Type is String)
          • long_name: landsat percentage canopy (Type is String)
          • description: Average percentage value of the valid (value <= 100) Landsat Tree Cover Continuous Fields product for each 100 m segment (Type is String)
          • source: Land ATBD section 2.2.24 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_mean_canopy[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: mean canopy height (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)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_h_metrics[ 0..77] [ 0..8] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: canopy height metrics (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: 25,50,60,70,75,80,85,90,95%. (Type is String)
          • source: Land ATBD section 2.2.3 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • n_toc_photons[ 0..77] (Type is Int32)
        • attributes
          • units: 1 (Type is String)
          • long_name: number top of canopy photons (Type is String)
          • description: The number of photons classified as top of canopy within the segment. (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_flag[ 0..77] (Type is Int32)
        • attributes
          • _FillValue: 2147483647 (Type is Int32)
          • units: 1 (Type is String)
          • long_name: canopy flag (Type is String)
          • description: Flag indicating that canopy was detected using the Landsat Tree Cover Continuous Fields data product. If percent of canopy cover along the L-km segment is greater than 5%, then canopy is assumed to be present; else, no canopy is assumed present. (Type is String)
          • source: Land ATBD section 2.2.22 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • flag_meanings: no_canopy_present canopy_present (Type is String)
          • flag_values: 0, 1 (Type is Int32)
      • landsat_flag[ 0..77] (Type is Int32)
        • attributes
          • _FillValue: 2147483647 (Type is Int32)
          • units: 1 (Type is String)
          • long_name: landsat flag (Type is String)
          • description: Flag indicating that more than 50% of the Landsat Continuous Cover product have values > 100 for the L-Km segment. Canopy is assumed present along the L-km segment if landsat_flag is 1. (Type is String)
          • source: Land ATBD section 2.2.25 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • flag_meanings: canopy_not_assumed_present canopy_assumed_present (Type is String)
          • flag_values: 0, 1 (Type is Int32)
      • h_max_canopy_abs[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute maximum canopy height (Type is String)
          • description: Maximum of individual absolute canopy heights within segment referenced above the WGS84 ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_canopy_uncertainty[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: segment canopy height uncertainty (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 in the Land ATBD (Type is String)
          • source: Land ATBD section 1.5 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_openness[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: 1 (Type is String)
          • long_name: canopy openness (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)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_max_canopy[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: maximum canopy height (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)
          • source: Land ATBD section 2.2.12 (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[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: uncertainty of h_te_mean (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 (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_mean[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: mean terrain height (Type is String)
          • description: The mean of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_min[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: minimum terrain height (Type is String)
          • description: The minimum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_interp[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: interpolated terrain surface height (Type is String)
          • description: Interpolated terrain surface height above the WGS84 Ellipsoid at the midpoint of the segment. (Type is String)
          • source: Land ATBD section 4.9 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_max[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: maximum terrain height (Type is String)
          • description: The maximum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_skew[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: skew of terrain heights (Type is String)
          • description: The skewness of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_median[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: median terrain height (Type is String)
          • description: The median of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_best_fit[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: segment terrain height best fit (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)
          • source: Land ATBD section 2.1.15 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_std[ 0..77] (Type is Float32)
        • attributes
          • long_name: segment terrain roughness (Type is String)
          • description: The standard deviation of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
      • terrain_slope[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: 1 (Type is String)
          • long_name: segment terrain slope (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)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • n_te_photons[ 0..77] (Type is Int32)
        • attributes
          • units: 1 (Type is String)
          • long_name: number of ground photons (Type is String)
          • description: The number of the photons classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_mode[ 0..77] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: mode of terrain heights (Type is String)
          • description: The mode of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
gt1l(Type is Group)
  • attributes
    • Description: Each group contains the segments for one Ground Track. As ICESat-2 orbits the earth, sequential transmit pulses illuminate six ground tracks on the surface of the earth. The track width is approximately 14m. Each ground track is numbered, according to the laser spot number that generates a given ground track. Ground tracks are numbered from the left to the right in the direction of spacecraft travel as: 1L, 1R in the left-most pair of beams; 2L, 2R for the center pair of beams; and 3L, 3R for the right-most pair of beams. (Type is String)
    • atlas_pce: pce3 (Type is String)
    • atlas_beam_type: weak (Type is String)
    • groundtrack_id: gt1l (Type is String)
    • atmosphere_profile: profile_1 (Type is String)
    • atlas_spot_number: 6 (Type is String)
    • sc_orientation: Forward (Type is String)
  • signal_photons(Type is Group)
    • attributes
      • Description: Contains parameters related to individual photons. (Type is String)
      • data_rate: Data are stored at the signal-photon classification rate. (Type is String)
    • delta_time[ 0..17464] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • long_name: delta time (Type is String)
        • standard_name: time (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)
        • source: ATL03 (Type is String)
    • classed_pc_indx[ 0..17464] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: indicies of classed photons (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)
        • source: Retained from prior a_alt_science_ph packet (Type is String)
        • coordinates: delta_time (Type is String)
    • classed_pc_flag[ 0..17464] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: photon land atbd classification (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)
        • source: Land ATBD section 4.10 (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)
    • d_flag[ 0..17464] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: dragann flag (Type is String)
        • description: Flag indicating the labeling of DRAGANN noise filtering for a given photon. (Type is String)
        • source: Land ATBD section 2.3.5 (Type is String)
        • coordinates: delta_time (Type is String)
        • flag_meanings: noise signal (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • ph_segment_id[ 0..17464] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: segment id of photon (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)
        • source: Retained from prior a_alt_science_ph packet (Type is String)
        • coordinates: delta_time (Type is String)
  • land_segments(Type is Group)
    • attributes
      • 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)
    • longitude[ 0..133] (Type is Float32)
      • attributes
        • units: degrees (Type is String)
        • long_name: longitude (Type is String)
        • standard_name: longitude (Type is String)
        • description: Longitude of the center-most signal photon within each segment. (Type is String)
        • source: Land ATBD section 2.4 (Type is String)
        • coordinates: delta_time latitude (Type is String)
        • valid_min: -180. (Type is Float32)
        • valid_max: 180. (Type is Float32)
    • latitude[ 0..133] (Type is Float32)
      • attributes
        • units: degrees (Type is String)
        • long_name: latitude (Type is String)
        • standard_name: latitude (Type is String)
        • description: Latitude of the center-most signal photon within each segment. (Type is String)
        • source: Land ATBD section 2.4 (Type is String)
        • coordinates: delta_time longitude (Type is String)
        • valid_min: -90. (Type is Float32)
        • valid_max: 90. (Type is Float32)
    • delta_time[ 0..133] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • long_name: mean_pass_time (Type is String)
        • standard_name: time (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)
        • source: Land ATBD section 2.4 (Type is String)
        • coordinates: latitude longitude (Type is String)
    • dem_flag[ 0..133] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: dem source flag (Type is String)
        • description: Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=GMTED, 3=MSS, 4=Antarctic. (Type is String)
        • source: Atmosphere ATBD (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: none arctic gmted mss antarctic (Type is String)
        • flag_values: 0, 1, 2, 3, 4 (Type is Int8)
        • valid_min: 0 (Type is Int8)
        • valid_max: 4 (Type is Int8)
    • msw_flag[ 0..133] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • long_name: multiple scattering warning flag (Type is String)
        • description: Multiple Scattering warning flag. The multiple scattering warning flag (ATL09 parameter msw_flag) has values from -1 to 5 where zero means no multiple scattering and 5 the greatest. 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 -1 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 -1 to occur only during daylight. (Type is String)
        • source: ATL09 (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: -1, 0, 1, 2, 3, 4, 5 (Type is Int8)
    • cloud_flag_atm[ 0..133] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • long_name: cloud flag atm (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)
        • source: ATL09 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • valid_min: 0 (Type is Int8)
        • valid_max: 10 (Type is Int8)
    • snr[ 0..133] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • long_name: signal to noise ratio (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)
        • source: ATBD section 2.5.14 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_across[ 0..133] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: sigma atlas y (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • layer_flag[ 0..133] (Type is Int8)
      • attributes
        • contentType: modelResult (Type is String)
        • long_name: consolidated cloud flag (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)
        • source: ATL09 (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[ 0..133] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • long_name: segment snowcover (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)
        • source: ATBD section 4.2.16 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: ice_free_water snow_free_land snow ice (Type is String)
        • flag_values: 0, 1, 2, 3 (Type is Int8)
        • valid_min: 0 (Type is Int8)
        • valid_max: 3 (Type is Int8)
    • beam_azimuth[ 0..133] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: radians (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: beam azimuth (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • solar_azimuth[ 0..133] (Type is Float32)
      • attributes
        • units: degrees_east (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: solar azimuth (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)
        • source: ATL03g ATBD (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • psf_flag[ 0..133] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: point spread function flag (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)
        • source: Land/Veg ATBD (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: below_threshold above_threshold (Type is String)
        • flag_values: 0, 1 (Type is Int8)
        • valid_min: 0 (Type is Int8)
        • valid_max: 1 (Type is Int8)
    • segment_watermask[ 0..133] (Type is Int32)
      • attributes
        • _FillValue: 255 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: segment watermask (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)
        • source: ATBD section 2.4.15 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: no_water water (Type is String)
        • flag_values: 0, 1 (Type is Int32)
        • valid_min: 0 (Type is Int32)
        • valid_max: 1 (Type is Int32)
    • delta_time_end[ 0..133] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: delta time end (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)
        • source: Derived (gps_seconds-gps_sec_offset) (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • segment_id_end[ 0..133] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: end geolocation segment bin (Type is String)
        • description: Geolocation segment number of the last photon in the land segment. (Type is String)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • surf_type[ 0..133] [ 0..4] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: surface type (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)
        • source: ATL03 ATBD, Section 4 (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)
        • valid_min: 0 (Type is Int8)
        • valid_max: 1 (Type is Int8)
    • brightness_flag[ 0..133] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • long_name: brightness flag (Type is String)
        • description: Flag indicating that the ground surface is bright (e.g. snow-covered or other bright surfaces) (Type is String)
        • source: Land ATBD section 2.4.21 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: not_bright_surface bright_surface (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • segment_landcover[ 0..133] (Type is Int32)
      • attributes
        • _FillValue: 255 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: segment landcover (Type is String)
        • description: IGBP Land Cover Surface type classification as reference from MODIS Land Cover(ANC18) at the 0.5 arcsecond resolution. (Type is String)
        • source: ATBD section 2.4.14 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: Water Evergreen_Needleleaf_Forest Evergreen_Broadleaf_Forest Deciduous_Needleleaf_Forest Deciduous_Broadleaf_Forest Mixed_Forest Closed_Shrublands Open_Shrubland Woody_Savanna Savanna Grassland Wetland Croplands Urban Crop_Mosaic Permanent_Snow Barren (Type is String)
        • flag_values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 (Type is Int32)
        • valid_min: 0 (Type is Int32)
        • valid_max: 16 (Type is Int32)
    • ph_removal_flag[ 0..133] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: ph removal flag (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)
        • source: ATBD section 4.13 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: below_threshold above_threshold (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • asr[ 0..133] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • long_name: apparent surface reflectance (Type is String)
        • description: Apparent surface reflectance (Type is String)
        • source: ATL09 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_atlas_land[ 0..133] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: sigma atlas land (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. (Type is String)
        • source: Land ATBD section 2.5.13 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • segment_id_beg[ 0..133] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: begin geolocation segment bin (Type is String)
        • description: Geolocation segment number of the first photon in the land segment. (Type is String)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_along[ 0..133] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: sigma atlas x (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • dem_h[ 0..133] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: meters (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: dem height (Type is String)
        • description: Best available DEM (in priority of Arctic/Antarctic/GMTED/MSS) value at the geolocation point. Height is in meters above the WGS84 Ellipsoid. (Type is String)
        • source: GIMP, GMTED,MSS (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • beam_coelev[ 0..133] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: radians (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: beam co-elevation (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_topo[ 0..133] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: sigma atlas topo (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)
        • source: Land ATBD section 2.5.12 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • night_flag[ 0..133] (Type is Int32)
      • attributes
        • _FillValue: 2147483647 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: night flag (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)
        • source: Land ATBD section 2.4.8 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: day night (Type is String)
        • flag_values: 0, 1 (Type is Int32)
    • delta_time_beg[ 0..133] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: delta time begin (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)
        • source: Derived (gps_seconds-gps_sec_offset) (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_h[ 0..133] (Type is Float32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • long_name: height uncertainty (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
    • last_seg_extend[ 0..133] (Type is Float32)
      • attributes
        • units: kilometers (Type is String)
        • long_name: last segment extended (Type is String)
        • standard_name: last_seg_extend (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)
        • source: Land ATBD 13March2019, Section 2.4.20 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • atlas_pa[ 0..133] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: radians (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: atlas pointing angle (Type is String)
        • description: Off nadir pointing angle (in radians) of the satellite to increase spatial sampling in the non-polar regions. ATLAS_PA =90degs-beam_coelev. (Type is String)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • ph_ndx_beg[ 0..133] (Type is Int64)
      • attributes
        • units: 1 (Type is String)
        • long_name: photon index begin (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)
        • source: Derived (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • solar_elevation[ 0..133] (Type is Float32)
      • attributes
        • units: degrees (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: solar elevation (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)
        • source: ATL03g ATBD (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • rgt[ 0..133] (Type is Int16)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: reference ground track (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)
        • source: Operations (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • valid_min: 1 (Type is Int16)
        • valid_max: 1387 (Type is Int16)
    • cloud_fold_flag[ 0..133] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • contentType: modelResult (Type is String)
        • long_name: cloud folding flag (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)
        • source: ATL09 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: no_folding goes5_indicates profile_indicates both_indicate (Type is String)
        • flag_values: 0, 1, 2, 3 (Type is Int8)
        • valid_min: 0 (Type is Int8)
        • valid_max: 3 (Type is Int8)
    • n_seg_ph[ 0..133] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • long_name: number of photons (Type is String)
        • description: Number of photons within each land segment. (Type is String)
        • source: Derived (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • terrain_flg[ 0..133] (Type is Int32)
      • attributes
        • _FillValue: 2147483647 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: terrain flag (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)
        • source: Land ATBD section 2.4.8 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: below_threshold above_threshold (Type is String)
        • flag_values: 0, 1 (Type is Int32)
    • urban_flag[ 0..133] (Type is Int32)
      • attributes
        • _FillValue: 2147483647 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: segment urban flag (Type is String)
        • description: The urban flag indicates that a segment is likely located over an urban area. (Type is String)
        • source: Land ATBD section 2.4.17 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: not_urban urban (Type is String)
        • flag_values: 0, 1 (Type is Int32)
    • dem_removal_flag[ 0..133] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: dem removal flag (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)
        • source: ATBD section 2.4.11 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: below_threshold above_threshold (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • h_dif_ref[ 0..133] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: meters (Type is String)
        • long_name: h dif from reference (Type is String)
        • description: Difference between h_te_median and ref_DEM (Type is String)
        • source: Land ATBD section 2.4 (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[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: height canopy (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)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_rh_conf[ 0..133] (Type is Int8)
        • attributes
          • units: 1 (Type is String)
          • contentType: modelResult (Type is String)
          • long_name: canopy relative height confidence (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)
          • source: Land/Veg ATBD 13March2019, Section 2.2.21 (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)
          • valid_min: 0 (Type is Int8)
          • valid_max: 2 (Type is Int8)
      • h_median_canopy_abs[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute segment median canopy height (Type is String)
          • description: The median of individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.6 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_min_canopy[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: minimum canopy height (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)
          • source: Land ATBD section 2.2.10 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_mean_canopy_abs[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute mean canopy height (Type is String)
          • description: Mean of the individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.4 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_median_canopy[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: median canopy height (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)
          • source: Land ATBD section 2.2.8 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_canopy_abs[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute segment canopy height (Type is String)
          • description: The 98% height of all the absolute individual canopy heights referenced above the WGS84 ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.2 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • toc_roughness[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: top of canopy roughness (Type is String)
          • description: Standard deviation of the relative heights of all photons classified as top of canopy within the segment (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_min_canopy_abs[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute minimum canopy height (Type is String)
          • description: The minimum of absolute individual canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.9 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_dif_canopy[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: canopy diff to median height (Type is String)
          • description: Difference between h_canopy and h_median_canopy (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_canopy_quad[ 0..133] (Type is Float32)
        • attributes
          • long_name: canopy quadratic mean (Type is String)
          • description: The quadratic mean height of individual classified relative canopy photon heights above the estimated terrain surface. (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
      • n_ca_photons[ 0..133] (Type is Int32)
        • attributes
          • units: 1 (Type is String)
          • long_name: number canopy photons (Type is String)
          • description: The number of photons classified as canopy within the segment. (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • centroid_height[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: centroid height (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)
          • source: Land ATBD section 2.2.22 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_h_metrics_abs[ 0..133] [ 0..8] (Type is Float32)
        • attributes
          • long_name: canopy absolute height metrics (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: 25,50,60,70,75,80,85,90,95%. (Type is String)
          • source: Land ATBD section 2.2.3 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
      • landsat_perc[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: 1 (Type is String)
          • long_name: landsat percentage canopy (Type is String)
          • description: Average percentage value of the valid (value <= 100) Landsat Tree Cover Continuous Fields product for each 100 m segment (Type is String)
          • source: Land ATBD section 2.2.24 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_mean_canopy[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: mean canopy height (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)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_h_metrics[ 0..133] [ 0..8] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: canopy height metrics (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: 25,50,60,70,75,80,85,90,95%. (Type is String)
          • source: Land ATBD section 2.2.3 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • n_toc_photons[ 0..133] (Type is Int32)
        • attributes
          • units: 1 (Type is String)
          • long_name: number top of canopy photons (Type is String)
          • description: The number of photons classified as top of canopy within the segment. (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_flag[ 0..133] (Type is Int32)
        • attributes
          • _FillValue: 2147483647 (Type is Int32)
          • units: 1 (Type is String)
          • long_name: canopy flag (Type is String)
          • description: Flag indicating that canopy was detected using the Landsat Tree Cover Continuous Fields data product. If percent of canopy cover along the L-km segment is greater than 5%, then canopy is assumed to be present; else, no canopy is assumed present. (Type is String)
          • source: Land ATBD section 2.2.22 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • flag_meanings: no_canopy_present canopy_present (Type is String)
          • flag_values: 0, 1 (Type is Int32)
      • landsat_flag[ 0..133] (Type is Int32)
        • attributes
          • _FillValue: 2147483647 (Type is Int32)
          • units: 1 (Type is String)
          • long_name: landsat flag (Type is String)
          • description: Flag indicating that more than 50% of the Landsat Continuous Cover product have values > 100 for the L-Km segment. Canopy is assumed present along the L-km segment if landsat_flag is 1. (Type is String)
          • source: Land ATBD section 2.2.25 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • flag_meanings: canopy_not_assumed_present canopy_assumed_present (Type is String)
          • flag_values: 0, 1 (Type is Int32)
      • h_max_canopy_abs[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute maximum canopy height (Type is String)
          • description: Maximum of individual absolute canopy heights within segment referenced above the WGS84 ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_canopy_uncertainty[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: segment canopy height uncertainty (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 in the Land ATBD (Type is String)
          • source: Land ATBD section 1.5 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_openness[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: 1 (Type is String)
          • long_name: canopy openness (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)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_max_canopy[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: maximum canopy height (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)
          • source: Land ATBD section 2.2.12 (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[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: uncertainty of h_te_mean (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 (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_mean[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: mean terrain height (Type is String)
          • description: The mean of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_min[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: minimum terrain height (Type is String)
          • description: The minimum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_interp[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: interpolated terrain surface height (Type is String)
          • description: Interpolated terrain surface height above the WGS84 Ellipsoid at the midpoint of the segment. (Type is String)
          • source: Land ATBD section 4.9 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_max[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: maximum terrain height (Type is String)
          • description: The maximum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_skew[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: skew of terrain heights (Type is String)
          • description: The skewness of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_median[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: median terrain height (Type is String)
          • description: The median of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_best_fit[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: segment terrain height best fit (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)
          • source: Land ATBD section 2.1.15 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_std[ 0..133] (Type is Float32)
        • attributes
          • long_name: segment terrain roughness (Type is String)
          • description: The standard deviation of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
      • terrain_slope[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: 1 (Type is String)
          • long_name: segment terrain slope (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)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • n_te_photons[ 0..133] (Type is Int32)
        • attributes
          • units: 1 (Type is String)
          • long_name: number of ground photons (Type is String)
          • description: The number of the photons classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_mode[ 0..133] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: mode of terrain heights (Type is String)
          • description: The mode of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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
      • units: 1 (Type is String)
      • contentType: qualityInformation (Type is String)
      • long_name: Granule Failure Reason (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)
      • source: Operations (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)
      • valid_min: 0 (Type is Int32)
      • valid_max: 5 (Type is Int32)
  • qa_granule_pass_fail[ 0..0] (Type is Int32)
    • attributes
      • units: 1 (Type is String)
      • contentType: qualityInformation (Type is String)
      • long_name: Granule Pass Flag (Type is String)
      • description: Flag indicating granule quality. 0=granule passes automatic QA. 1=granule fails automatic QA. (Type is String)
      • source: Operations (Type is String)
      • flag_meanings: PASS FAIL (Type is String)
      • flag_values: 0, 1 (Type is Int32)
      • valid_min: 0 (Type is Int32)
      • valid_max: 1 (Type is Int32)
gt3l(Type is Group)
  • attributes
    • Description: Each group contains the segments for one Ground Track. As ICESat-2 orbits the earth, sequential transmit pulses illuminate six ground tracks on the surface of the earth. The track width is approximately 14m. Each ground track is numbered, according to the laser spot number that generates a given ground track. Ground tracks are numbered from the left to the right in the direction of spacecraft travel as: 1L, 1R in the left-most pair of beams; 2L, 2R for the center pair of beams; and 3L, 3R for the right-most pair of beams. (Type is String)
    • atlas_pce: pce1 (Type is String)
    • atlas_beam_type: weak (Type is String)
    • groundtrack_id: gt3l (Type is String)
    • atmosphere_profile: profile_3 (Type is String)
    • atlas_spot_number: 2 (Type is String)
    • sc_orientation: Forward (Type is String)
  • signal_photons(Type is Group)
    • attributes
      • Description: Contains parameters related to individual photons. (Type is String)
      • data_rate: Data are stored at the signal-photon classification rate. (Type is String)
    • delta_time[ 0..1861] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • long_name: delta time (Type is String)
        • standard_name: time (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)
        • source: ATL03 (Type is String)
    • classed_pc_indx[ 0..1861] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: indicies of classed photons (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)
        • source: Retained from prior a_alt_science_ph packet (Type is String)
        • coordinates: delta_time (Type is String)
    • classed_pc_flag[ 0..1861] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: photon land atbd classification (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)
        • source: Land ATBD section 4.10 (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)
    • d_flag[ 0..1861] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: dragann flag (Type is String)
        • description: Flag indicating the labeling of DRAGANN noise filtering for a given photon. (Type is String)
        • source: Land ATBD section 2.3.5 (Type is String)
        • coordinates: delta_time (Type is String)
        • flag_meanings: noise signal (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • ph_segment_id[ 0..1861] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: segment id of photon (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)
        • source: Retained from prior a_alt_science_ph packet (Type is String)
        • coordinates: delta_time (Type is String)
gt2l(Type is Group)
  • attributes
    • Description: Each group contains the segments for one Ground Track. As ICESat-2 orbits the earth, sequential transmit pulses illuminate six ground tracks on the surface of the earth. The track width is approximately 14m. Each ground track is numbered, according to the laser spot number that generates a given ground track. Ground tracks are numbered from the left to the right in the direction of spacecraft travel as: 1L, 1R in the left-most pair of beams; 2L, 2R for the center pair of beams; and 3L, 3R for the right-most pair of beams. (Type is String)
    • atlas_pce: pce2 (Type is String)
    • atlas_beam_type: weak (Type is String)
    • groundtrack_id: gt2l (Type is String)
    • atmosphere_profile: profile_2 (Type is String)
    • atlas_spot_number: 4 (Type is String)
    • sc_orientation: Forward (Type is String)
  • signal_photons(Type is Group)
    • attributes
      • Description: Contains parameters related to individual photons. (Type is String)
      • data_rate: Data are stored at the signal-photon classification rate. (Type is String)
    • delta_time[ 0..2874] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • long_name: delta time (Type is String)
        • standard_name: time (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)
        • source: ATL03 (Type is String)
    • classed_pc_indx[ 0..2874] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: indicies of classed photons (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)
        • source: Retained from prior a_alt_science_ph packet (Type is String)
        • coordinates: delta_time (Type is String)
    • classed_pc_flag[ 0..2874] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: photon land atbd classification (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)
        • source: Land ATBD section 4.10 (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)
    • d_flag[ 0..2874] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: dragann flag (Type is String)
        • description: Flag indicating the labeling of DRAGANN noise filtering for a given photon. (Type is String)
        • source: Land ATBD section 2.3.5 (Type is String)
        • coordinates: delta_time (Type is String)
        • flag_meanings: noise signal (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • ph_segment_id[ 0..2874] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: segment id of photon (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)
        • source: Retained from prior a_alt_science_ph packet (Type is String)
        • coordinates: delta_time (Type is String)
ancillary_data(Type is Group)
  • attributes
    • Description: Contains information ancillary to the data product. This may include product characteristics, instrument characteristics and/or processing constants. (Type is String)
    • data_rate: Data within this group pertain to the granule in its entirety. (Type is String)
  • release[ 0..0] (Type is String)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Release Number (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)
      • source: Operations (Type is String)
  • end_geoseg[ 0..0] (Type is Int32)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Ending Geolocation Segment (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)
      • source: Derived (Type is String)
  • version[ 0..0] (Type is String)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Version (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)
      • source: Operations (Type is String)
  • end_region[ 0..0] (Type is Int32)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Ending Region (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)
      • source: Derived (Type is String)
  • atlas_sdp_gps_epoch[ 0..0] (Type is Float64)
    • attributes
      • units: seconds since 1980-01-06T00:00:00.000000Z (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: ATLAS Epoch Offset (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)
      • source: Operations (Type is String)
  • end_rgt[ 0..0] (Type is Int32)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Ending Reference Groundtrack (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)
      • source: Derived (Type is String)
      • valid_min: 1 (Type is Int32)
      • valid_max: 1387 (Type is Int32)
  • end_delta_time[ 0..0] (Type is Float64)
    • attributes
      • units: seconds since 2018-01-01 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: ATLAS End Time (Actual) (Type is String)
      • standard_name: time (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)
      • source: Derived (Type is String)
  • end_orbit[ 0..0] (Type is Int32)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Ending Orbit Number (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)
      • source: Derived (Type is String)
  • start_cycle[ 0..0] (Type is Int32)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Starting Cycle (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)
      • source: Derived (Type is String)
      • valid_min: 0 (Type is Int32)
      • valid_max: 99 (Type is Int32)
  • data_end_utc[ 0..0] (Type is String)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: End UTC Time of Granule (CCSDS-A, Actual) (Type is String)
      • description: UTC (in CCSDS-A format) of the last data point within the granule. (Type is String)
      • source: Derived (Type is String)
  • control[ 0..0] (Type is String)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Control File (Type is String)
      • description: PGE-specific control file used to generate this granule. To re-use, replace breaks (BR) with linefeeds. (Type is String)
      • source: Operations (Type is String)
  • start_gpssow[ 0..0] (Type is Float64)
    • attributes
      • units: seconds (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Start GPS SOW of Granule (Actual) (Type is String)
      • description: GPS seconds-of-week of the first data point in the granule. (Type is String)
      • source: Derived (Type is String)
  • granule_end_utc[ 0..0] (Type is String)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: End UTC Time of Granule (CCSDS-A, Requested) (Type is String)
      • description: Requested end time (in UTC CCSDS-A) of this granule. (Type is String)
      • source: Derived (Type is String)
  • end_cycle[ 0..0] (Type is Int32)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Ending Cycle (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)
      • source: Derived (Type is String)
      • valid_min: 0 (Type is Int32)
      • valid_max: 99 (Type is Int32)
  • granule_start_utc[ 0..0] (Type is String)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Start UTC Time of Granule (CCSDS-A, Requested) (Type is String)
      • description: Requested start time (in UTC CCSDS-A) of this granule. (Type is String)
      • source: Derived (Type is String)
  • start_delta_time[ 0..0] (Type is Float64)
    • attributes
      • units: seconds since 2018-01-01 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: ATLAS Start Time (Actual) (Type is String)
      • standard_name: time (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)
      • source: Derived (Type is String)
  • start_geoseg[ 0..0] (Type is Int32)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Starting Geolocation Segment (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)
      • source: Derived (Type is String)
  • start_orbit[ 0..0] (Type is Int32)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Starting Orbit Number (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)
      • source: Derived (Type is String)
  • data_start_utc[ 0..0] (Type is String)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Start UTC Time of Granule (CCSDS-A, Actual) (Type is String)
      • description: UTC (in CCSDS-A format) of the first data point within the granule. (Type is String)
      • source: Derived (Type is String)
  • end_gpsweek[ 0..0] (Type is Int32)
    • attributes
      • units: weeks from 1980-01-06 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Ending GPSWeek of Granule (Actual) (Type is String)
      • description: GPS week number of the last data point in the granule. (Type is String)
      • source: Derived (Type is String)
  • start_rgt[ 0..0] (Type is Int32)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Starting Reference Groundtrack (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)
      • source: Derived (Type is String)
      • valid_min: 1 (Type is Int32)
      • valid_max: 1387 (Type is Int32)
  • end_gpssow[ 0..0] (Type is Float64)
    • attributes
      • units: seconds (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Ending GPS SOW of Granule (Actual) (Type is String)
      • description: GPS seconds-of-week of the last data point in the granule. (Type is String)
      • source: Derived (Type is String)
  • qa_at_interval[ 0..0] (Type is Float64)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: QA Along-Track Interval (Type is String)
      • description: Statistics time interval for along-track QA data. (Type is String)
      • source: control (Type is String)
  • start_region[ 0..0] (Type is Int32)
    • attributes
      • units: 1 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Starting Region (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)
      • source: Derived (Type is String)
  • start_gpsweek[ 0..0] (Type is Int32)
    • attributes
      • units: weeks from 1980-01-06 (Type is String)
      • contentType: auxiliaryInformation (Type is String)
      • long_name: Start GPSWeek of Granule (Actual) (Type is String)
      • description: GPS week number of the first data point in the granule. (Type is String)
      • source: Derived (Type is String)
  • land(Type is Group)
    • attributes
      • Description: Constants used in the land_vegetation ATBD (Type is String)
    • ca_class[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • description: Canopy classification flag value. (Default = 2) (Type is String)
        • source: ATBD section 4.12 step 1 (Type is String)
        • long_name: Canopy class value (Type is String)
    • canopy_flag_switch[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • description: Controls entrance to the canopy flag subroutine . (Default = 1) (Type is String)
        • source: ATBD section 4.3 (Type is String)
        • long_name: canopy_flag switch (Type is String)
    • up_toc_bnd[ 0..0] (Type is Float32)
      • attributes
        • units: meters (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Upper bound restricting the search of a top of canopy surface. (Type is String)
        • description: Upper bound restricting the search of a top of canopy surface. (Default=1.0) (Type is String)
        • source: ATBD section 4.7 step 3 entered from section 4.8 (Type is String)
    • fnlgnd_filter_switch[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: finalground filter switch (Type is String)
        • description: Controls filtering based on FINALGROUND. (Default = 1) (Type is String)
        • source: ATBD section 4.13 step 2 (Type is String)
    • psf[ 0..0] (Type is Float32)
      • attributes
        • units: meters (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Point Spread Function (Type is String)
        • description: Parameter controlling identification of photons around an interpolated surface. (Default = 0.5) (Type is String)
        • source: ATBD section 4.7 step 12 (Type is String)
    • dem_removal_percent_limit[ 0..0] (Type is Float32)
      • attributes
        • units: percent (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: dem_removal_flag set threshold (Type is String)
        • description: Percent of photons in land segment failing DEM test to set dem_removal_flag. (default = 20.0) (Type is String)
        • source: ATBD section 2.4.11 (Type is String)
    • atl08_region[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: modelResult (Type is String)
        • long_name: atl08 region (Type is String)
        • standard_name: atl08_region (Type is String)
        • description: ATL08 region(s) encompassed by ATL03 granule being processed (Type is String)
        • source: Land ATBD 29March2019, Table 2.4 (Type is String)
    • can_noise_thresh[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Threshold for reclassification of canopy as noise (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)
        • source: ATBD section 4.11 step 6 (Type is String)
    • relief_hbot[ 0..0] (Type is Float32)
      • attributes
        • units: meters (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: lower relief percentile (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)
        • source: ATBD (section 4.5 step 6) (Type is String)
    • dem_filter_switch[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: dem_filter switch (Type is String)
        • description: Controls filtering based on DEM. (Default = 1) (Type is String)
        • source: ATBD section 4.5 step 5 (Type is String)
    • relief_htop[ 0..0] (Type is Float32)
      • attributes
        • units: meters (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Upper relief percentile (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)
        • source: ATBD (section 4.5 step 6) (Type is String)
    • dseg_buf[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: DRAGANN segment buffer size (Type is String)
        • description: DRAGANN segment buffer length in 20m geolocated segments along ground track. (Default=10) (Type is String)
        • source: ATBD section 4.2.1 step 1 (Type is String)
    • night_thresh[ 0..0] (Type is Float32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Threshold for night (Type is String)
        • description: Solar elevation threshold for determining night time conditions. (Default =0.0) (Type is String)
        • source: ATBD section 2.4.9 (Type is String)
    • h_canopy_perc[ 0..0] (Type is Float32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: h_canopy percentile (Type is String)
        • description: Percentile component of h_canopy parameter. (Default =0.95) (Type is String)
        • source: ATBD section 2.2.3 (Type is String)
    • up_filt_bnd[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Proportionality coefficient for controlling the bounds of the filter window size as a function of number of signal photons. (Type is String)
        • description: Lower bound of the filter window size function. (Default = 46) (Type is String)
        • source: ATBD section 4.4 step 2 (Type is String)
    • lw_filt_bnd[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Proportionality coefficient for controlling the bounds of the filter window size as a function of number of signal photons. (Type is String)
        • description: Lower bound of the filter window size function. (Default = 5) (Type is String)
        • source: ATBD section 4.4 step 2 (Type is String)
    • ph_removal_percent_limit[ 0..0] (Type is Float32)
      • attributes
        • units: percent (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: ph_removal_flag set threshold (Type is String)
        • description: Percent of photons in land segment removed to set ph_removal_flag. (default = 50.0) (Type is String)
        • source: ATBD section 4.13 step 4 (Type is String)
    • canopy_seg[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: segment size in canopy filter (Type is String)
        • description: Segment in number of signal photons for filtering sparse canopy cover. (Default = 500) (Type is String)
        • source: ATBD section 4.11 step 6 (Type is String)
    • max_try[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Maximum try count (Type is String)
        • description: Maximum number of tries to compute a P value in alternative DRAGANN (Type is String)
        • source: ATBD section 4.2.1 step 17 (Type is String)
    • bin_size_n[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: neighbor histogram bin size (Type is String)
        • description: Size of neighbor histogram bins in number of neighbors in DRAGANN. (Default = 1) (Type is String)
        • source: ATBD (section 4.2 step 4) (Type is String)
    • lw_gnd_bnd[ 0..0] (Type is Float32)
      • attributes
        • units: meters (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Lower bound restricting the search of a ground surface in canopy cases. (Type is String)
        • description: Lower bound restricting the search of a ground surface in canopy cases. (Default = -4.0) (Type is String)
        • source: ATBD section 4.7 step 3 (Type is String)
    • del_mu[ 0..0] (Type is Float32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Step size for optimizing the mean parameter of Gaussian function. (Type is String)
        • description: Step size for optimizing the mean parameter of Gaussian function. (Default = 0.2) (Type is String)
        • source: ATBD section 4.2 step 7 (Type is String)
    • lw_toc_cut[ 0..0] (Type is Float32)
      • attributes
        • units: meters (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Lower cutoff for top of canopy (Type is String)
        • description: Lower cutoff for top of canopy surface. (Default = 2.0) (Type is String)
        • source: ATBD section 4.8 step 10 (Type is String)
    • class_thresh[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Threshold flag value for classification of photons as signal via input from ATL03 (Type is String)
        • description: Threshold flag value for classification of photons as signal via input from ATL03. (Default =3) (Type is String)
        • source: ATBD section 4.2 step 17 (Type is String)
    • lseg_buf[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Long segment buffer size (Type is String)
        • description: Overlapping long segment buffer size in 20m geosegments along ground track. (Default=10) (Type is String)
        • source: ATBD section 4.1 step 2 (Type is String)
    • lw_toc_bnd[ 0..0] (Type is Float32)
      • attributes
        • units: meters (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Lower bound restricting the search of a top of canopy surface. (Type is String)
        • description: Lower bound restricting the search of a top of canopy surface. (Default = -4.0) (Type is String)
        • source: section 4.7 step 3 entered from section 4.8 (Type is String)
    • up_toc_cut[ 0..0] (Type is Float32)
      • attributes
        • units: meters (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: upper cutoff of top of canopy surface. (Type is String)
        • description: Upper cutoff for top of canopy surface. (Default = 150.0) (Type is String)
        • source: ATBD section 4.8 step 10 (Type is String)
    • gnd_stat_thresh[ 0..0] (Type is Float32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Threshold for terrain statistics (Type is String)
        • description: Minimum percentage of terrain photons to compute statistics upon. (Default =0.05) (Type is String)
        • source: ATBD section 4.13 step 2 (Type is String)
    • iter_max[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Maximum number of iterations for optimizing the Gaussian parameters for fitting of histogram. (Type is String)
        • description: Maximum number of iterations for optimizing the Gaussian parameters for fitting of histogram. (Default = 10) (Type is String)
        • source: ATBD section 4.2 step 7 (Type is String)
    • gthresh_factor[ 0..0] (Type is Float32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: threshold for Gaussian Elimination (Type is String)
        • description: Controls threshold for Gaussian Elimination. (Default = 0.1) (Type is String)
        • source: ATBD sGaussian Rejection section of Appendix A (Type is String)
    • bright_thresh[ 0..0] (Type is Float32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: brightness flag average ph per shot (Type is String)
        • description: Threshold to set brightness_flag, average ground photons per shot. (Default = 3.0) (Type is String)
        • source: ATBD section 2.4.21 (Type is String)
    • dseg[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: DRAGANN segment size (Type is String)
        • description: DRAGANN segment length in 20m geolocated segments along ground track. (Default=170) (Type is String)
        • source: ATBD section 4.2.1 step 1 (Type is String)
    • bin_size_h[ 0..0] (Type is Float32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: neighbor histogram bin size (Type is String)
        • description: Histogram bin size for the alternative DRAGANN algorithm. (Default = 1.0) (Type is String)
        • source: ATBD (section 4.2.1 step 3) (Type is String)
    • up_gnd_bnd[ 0..0] (Type is Float32)
      • attributes
        • units: meters (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Upper bound restricting the search of a ground surface in canopy cases. (Type is String)
        • description: Upper bound restricting the search of a ground surface in canopy cases. (Default = 1.0) (Type is String)
        • source: ATBD (section 4.7 step 3) (Type is String)
    • min_nphs[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Minimum input photons (Type is String)
        • description: Minimum number of input photons from ATL03 to process. (default=1) (Type is String)
        • source: Operations (Type is String)
    • tc_thresh[ 0..0] (Type is Float32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Canopy Flag threshold (Type is String)
        • description: Percentage threshold for average L-km segment tree cover to be considered canopy. (Default = 5.0) (Type is String)
        • source: ATBD section 4.3 steps 6 and 7 (Type is String)
    • te_class[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Terrain class value (Type is String)
        • description: Terrain classification flag value. (Default = 1) (Type is String)
        • source: ATBD section 4.12 step 1 (Type is String)
    • toc_class[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Top of canopy class value (Type is String)
        • description: Top of canopy classification flag value. (Default = 3) (Type is String)
        • source: ATBD section 4.12 step 1 (Type is String)
    • iter_gnd[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Iterations of smoothing of interpolated ground surface for ground estimate. (Type is String)
        • description: Iterations of smoothing of interpolated ground surface for refinement. (Default = 10) (Type is String)
        • source: ATBD section 4.10 step 1 (Type is String)
    • max_atl03files[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Maximum number of input ATL03s (Type is String)
        • description: Maximum number of input ATL03 files. (Default = 200) (Type is String)
        • source: Operations (Type is String)
    • noise_class[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Noise class value (Type is String)
        • description: Noise classification flag value. (Default = 0) (Type is String)
        • source: ATBD section 4.12 step 1 (Type is String)
    • outlier_filter_switch[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: outlier_filter switch (Type is String)
        • description: Controls entrance to the outlier filter subroutine. (Default = 1) (Type is String)
        • source: ATBD section 4.6 (Type is String)
    • dragann_switch[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: DRAGANN switch (Type is String)
        • description: Controls entrance to the DRAGANN subroutine. (Default =1) (Type is String)
        • source: ATBD section 4.2 (Type is String)
    • proc_geoseg[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Geosegment process interval length (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)
        • source: Operations (Type is String)
    • can_stat_thresh[ 0..0] (Type is Float32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Threshold for canopy statistics (Type is String)
        • description: Minimum percentage of canopy photons to compute statistics upon. (Default =0.05) (Type is String)
        • source: ATBD section 4.14.1 step 1 (Type is String)
    • lseg[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Long segment size (Type is String)
        • description: Long segment size in number of 20 meter segments along ground track. (Default=500) (Type is String)
        • source: ATBD section 4.1 step 1 (Type is String)
    • max_atl09files[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Maximum number of input ATL09s (Type is String)
        • description: Maximum number of input ATL09 files. (Default = 200) (Type is String)
        • source: Operations (Type is String)
    • ref_dem_limit[ 0..0] (Type is Float32)
      • attributes
        • units: meters (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: DEM threshold (Type is String)
        • description: Reference DEM limit used to reclassify signal as noise. (default = 120.0) (Type is String)
        • source: ATBD section 4.5 step 4 (Type is String)
    • max_peaks[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Maximum number of Gaussian peaks to fit in the data set (Type is String)
        • description: Maximum number of Gaussian peaks to fit in the data set in DRAGANN. (Default =10) (Type is String)
        • source: ATBD section 4.2 step 9 (Type is String)
    • stat_thresh[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Threshold for land statistics (Type is String)
        • description: Minimum number of photons to compute statistics upon. (Default =50) (Type is String)
        • source: ATBD section 2 intro paragraph (Type is String)
    • sig_rsq_search[ 0..0] (Type is Float32)
      • attributes
        • units: meters^2 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Square Radius of filter for canopy (Type is String)
        • description: Top of canopy refinement square search radius. (Default = 225.0) (Type is String)
        • source: ATBD section 4.8 step 6 (Type is String)
    • del_amp[ 0..0] (Type is Float32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Step Gaussian Amplitude optimization (Type is String)
        • description: Step size for optimizing the amplitude variable of Gaussian function. (Default = 1.0) (Type is String)
        • source: ATBD section 4.2 step 7 (Type is String)
    • sseg[ 0..0] (Type is Float32)
      • attributes
        • units: meters (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Short Segment Length (Type is String)
        • description: Short segment length in meters. (Default = 100.0) (Type is String)
        • source: ATBD section 4.13 step 1 (Type is String)
    • shp_param[ 0..0] (Type is Float32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • 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)
        • description: Exponential coefficient of the filter window size as a function. (Default = 21.0E-06) (Type is String)
        • source: ATBD section 4.4 step 2 (Type is String)
    • del_sigma[ 0..0] (Type is Float32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Step size for optimizing the standard deviation parameter of Gaussian function. (Type is String)
        • description: Step size for optimizing the standard deviation parameter of Gaussian function. (Default = 0.5) (Type is String)
        • source: ATBD section 4.2 step 7 (Type is String)
    • cloud_filter_switch[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: cloud_filter switch (Type is String)
        • description: Controls entrance to the cloud_filter subroutine. (Default = 0) (Type is String)
        • source: ATBD section 4.1.1 (Type is String)
    • n_dec_mode[ 0..0] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Mode decimal parameter (Type is String)
        • description: Number of decimal places to consider in mode computation. (Default =1) (Type is String)
        • source: ATBD needed for section 4.13 step 3(h_te_mode) (Type is String)
    • ref_finalground_limit[ 0..0] (Type is Float32)
      • attributes
        • units: meters (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • description: Reference finalground limit used to reclassify signal as noise. (default = 150.0) (Type is String)
        • source: ATBD section 4.13 step 2 (Type is String)
        • long_name: finalground threshold (Type is String)
    • p_static[ 0..0] (Type is Float32)
      • attributes
        • units: 1 (Type is String)
        • contentType: auxiliaryInformation (Type is String)
        • long_name: Dragann Parameter (Type is String)
        • description: Parameter for controlling the search radius in nearest neighbor search in DRAGANN. (Default = 20) (Type is String)
        • source: ATBD section 4.2 step 1 (Type is String)
gt3r(Type is Group)
  • attributes
    • Description: Each group contains the segments for one Ground Track. As ICESat-2 orbits the earth, sequential transmit pulses illuminate six ground tracks on the surface of the earth. The track width is approximately 14m. Each ground track is numbered, according to the laser spot number that generates a given ground track. Ground tracks are numbered from the left to the right in the direction of spacecraft travel as: 1L, 1R in the left-most pair of beams; 2L, 2R for the center pair of beams; and 3L, 3R for the right-most pair of beams. (Type is String)
    • atlas_pce: pce1 (Type is String)
    • atlas_beam_type: strong (Type is String)
    • groundtrack_id: gt3r (Type is String)
    • atmosphere_profile: profile_3 (Type is String)
    • atlas_spot_number: 1 (Type is String)
    • sc_orientation: Forward (Type is String)
  • signal_photons(Type is Group)
    • attributes
      • Description: Contains parameters related to individual photons. (Type is String)
      • data_rate: Data are stored at the signal-photon classification rate. (Type is String)
    • delta_time[ 0..5879] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • long_name: delta time (Type is String)
        • standard_name: time (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)
        • source: ATL03 (Type is String)
    • classed_pc_indx[ 0..5879] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: indicies of classed photons (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)
        • source: Retained from prior a_alt_science_ph packet (Type is String)
        • coordinates: delta_time (Type is String)
    • classed_pc_flag[ 0..5879] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: photon land atbd classification (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)
        • source: Land ATBD section 4.10 (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)
    • d_flag[ 0..5879] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: dragann flag (Type is String)
        • description: Flag indicating the labeling of DRAGANN noise filtering for a given photon. (Type is String)
        • source: Land ATBD section 2.3.5 (Type is String)
        • coordinates: delta_time (Type is String)
        • flag_meanings: noise signal (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • ph_segment_id[ 0..5879] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: segment id of photon (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)
        • source: Retained from prior a_alt_science_ph packet (Type is String)
        • coordinates: delta_time (Type is String)
  • land_segments(Type is Group)
    • attributes
      • 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)
    • longitude[ 0..24] (Type is Float32)
      • attributes
        • units: degrees (Type is String)
        • long_name: longitude (Type is String)
        • standard_name: longitude (Type is String)
        • description: Longitude of the center-most signal photon within each segment. (Type is String)
        • source: Land ATBD section 2.4 (Type is String)
        • coordinates: delta_time latitude (Type is String)
        • valid_min: -180. (Type is Float32)
        • valid_max: 180. (Type is Float32)
    • latitude[ 0..24] (Type is Float32)
      • attributes
        • units: degrees (Type is String)
        • long_name: latitude (Type is String)
        • standard_name: latitude (Type is String)
        • description: Latitude of the center-most signal photon within each segment. (Type is String)
        • source: Land ATBD section 2.4 (Type is String)
        • coordinates: delta_time longitude (Type is String)
        • valid_min: -90. (Type is Float32)
        • valid_max: 90. (Type is Float32)
    • delta_time[ 0..24] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • long_name: mean_pass_time (Type is String)
        • standard_name: time (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)
        • source: Land ATBD section 2.4 (Type is String)
        • coordinates: latitude longitude (Type is String)
    • dem_flag[ 0..24] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: dem source flag (Type is String)
        • description: Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=GMTED, 3=MSS, 4=Antarctic. (Type is String)
        • source: Atmosphere ATBD (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: none arctic gmted mss antarctic (Type is String)
        • flag_values: 0, 1, 2, 3, 4 (Type is Int8)
        • valid_min: 0 (Type is Int8)
        • valid_max: 4 (Type is Int8)
    • msw_flag[ 0..24] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • long_name: multiple scattering warning flag (Type is String)
        • description: Multiple Scattering warning flag. The multiple scattering warning flag (ATL09 parameter msw_flag) has values from -1 to 5 where zero means no multiple scattering and 5 the greatest. 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 -1 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 -1 to occur only during daylight. (Type is String)
        • source: ATL09 (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: -1, 0, 1, 2, 3, 4, 5 (Type is Int8)
    • cloud_flag_atm[ 0..24] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • long_name: cloud flag atm (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)
        • source: ATL09 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • valid_min: 0 (Type is Int8)
        • valid_max: 10 (Type is Int8)
    • snr[ 0..24] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • long_name: signal to noise ratio (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)
        • source: ATBD section 2.5.14 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_across[ 0..24] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: sigma atlas y (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • layer_flag[ 0..24] (Type is Int8)
      • attributes
        • contentType: modelResult (Type is String)
        • long_name: consolidated cloud flag (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)
        • source: ATL09 (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[ 0..24] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • long_name: segment snowcover (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)
        • source: ATBD section 4.2.16 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: ice_free_water snow_free_land snow ice (Type is String)
        • flag_values: 0, 1, 2, 3 (Type is Int8)
        • valid_min: 0 (Type is Int8)
        • valid_max: 3 (Type is Int8)
    • beam_azimuth[ 0..24] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: radians (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: beam azimuth (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • solar_azimuth[ 0..24] (Type is Float32)
      • attributes
        • units: degrees_east (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: solar azimuth (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)
        • source: ATL03g ATBD (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • psf_flag[ 0..24] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: point spread function flag (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)
        • source: Land/Veg ATBD (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: below_threshold above_threshold (Type is String)
        • flag_values: 0, 1 (Type is Int8)
        • valid_min: 0 (Type is Int8)
        • valid_max: 1 (Type is Int8)
    • segment_watermask[ 0..24] (Type is Int32)
      • attributes
        • _FillValue: 255 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: segment watermask (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)
        • source: ATBD section 2.4.15 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: no_water water (Type is String)
        • flag_values: 0, 1 (Type is Int32)
        • valid_min: 0 (Type is Int32)
        • valid_max: 1 (Type is Int32)
    • delta_time_end[ 0..24] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: delta time end (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)
        • source: Derived (gps_seconds-gps_sec_offset) (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • segment_id_end[ 0..24] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: end geolocation segment bin (Type is String)
        • description: Geolocation segment number of the last photon in the land segment. (Type is String)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • surf_type[ 0..24] [ 0..4] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: surface type (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)
        • source: ATL03 ATBD, Section 4 (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)
        • valid_min: 0 (Type is Int8)
        • valid_max: 1 (Type is Int8)
    • brightness_flag[ 0..24] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • units: 1 (Type is String)
        • long_name: brightness flag (Type is String)
        • description: Flag indicating that the ground surface is bright (e.g. snow-covered or other bright surfaces) (Type is String)
        • source: Land ATBD section 2.4.21 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: not_bright_surface bright_surface (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • segment_landcover[ 0..24] (Type is Int32)
      • attributes
        • _FillValue: 255 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: segment landcover (Type is String)
        • description: IGBP Land Cover Surface type classification as reference from MODIS Land Cover(ANC18) at the 0.5 arcsecond resolution. (Type is String)
        • source: ATBD section 2.4.14 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: Water Evergreen_Needleleaf_Forest Evergreen_Broadleaf_Forest Deciduous_Needleleaf_Forest Deciduous_Broadleaf_Forest Mixed_Forest Closed_Shrublands Open_Shrubland Woody_Savanna Savanna Grassland Wetland Croplands Urban Crop_Mosaic Permanent_Snow Barren (Type is String)
        • flag_values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 (Type is Int32)
        • valid_min: 0 (Type is Int32)
        • valid_max: 16 (Type is Int32)
    • ph_removal_flag[ 0..24] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: ph removal flag (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)
        • source: ATBD section 4.13 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: below_threshold above_threshold (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • asr[ 0..24] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • long_name: apparent surface reflectance (Type is String)
        • description: Apparent surface reflectance (Type is String)
        • source: ATL09 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_atlas_land[ 0..24] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: sigma atlas land (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. (Type is String)
        • source: Land ATBD section 2.5.13 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • segment_id_beg[ 0..24] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: begin geolocation segment bin (Type is String)
        • description: Geolocation segment number of the first photon in the land segment. (Type is String)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_along[ 0..24] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: sigma atlas x (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • dem_h[ 0..24] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: meters (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: dem height (Type is String)
        • description: Best available DEM (in priority of Arctic/Antarctic/GMTED/MSS) value at the geolocation point. Height is in meters above the WGS84 Ellipsoid. (Type is String)
        • source: GIMP, GMTED,MSS (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • beam_coelev[ 0..24] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: radians (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: beam co-elevation (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_topo[ 0..24] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: sigma atlas topo (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)
        • source: Land ATBD section 2.5.12 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • night_flag[ 0..24] (Type is Int32)
      • attributes
        • _FillValue: 2147483647 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: night flag (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)
        • source: Land ATBD section 2.4.8 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: day night (Type is String)
        • flag_values: 0, 1 (Type is Int32)
    • delta_time_beg[ 0..24] (Type is Float64)
      • attributes
        • units: seconds since 2018-01-01 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: delta time begin (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)
        • source: Derived (gps_seconds-gps_sec_offset) (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • sigma_h[ 0..24] (Type is Float32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • long_name: height uncertainty (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)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: 1 (Type is String)
    • last_seg_extend[ 0..24] (Type is Float32)
      • attributes
        • units: kilometers (Type is String)
        • long_name: last segment extended (Type is String)
        • standard_name: last_seg_extend (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)
        • source: Land ATBD 13March2019, Section 2.4.20 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • atlas_pa[ 0..24] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: radians (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: atlas pointing angle (Type is String)
        • description: Off nadir pointing angle (in radians) of the satellite to increase spatial sampling in the non-polar regions. ATLAS_PA =90degs-beam_coelev. (Type is String)
        • source: ATL03 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • ph_ndx_beg[ 0..24] (Type is Int64)
      • attributes
        • units: 1 (Type is String)
        • long_name: photon index begin (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)
        • source: Derived (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • solar_elevation[ 0..24] (Type is Float32)
      • attributes
        • units: degrees (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: solar elevation (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)
        • source: ATL03g ATBD (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • rgt[ 0..24] (Type is Int16)
      • attributes
        • units: 1 (Type is String)
        • contentType: referenceInformation (Type is String)
        • long_name: reference ground track (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)
        • source: Operations (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • valid_min: 1 (Type is Int16)
        • valid_max: 1387 (Type is Int16)
    • cloud_fold_flag[ 0..24] (Type is Int8)
      • attributes
        • _FillValue: 127 (Type is Int8)
        • contentType: modelResult (Type is String)
        • long_name: cloud folding flag (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)
        • source: ATL09 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: no_folding goes5_indicates profile_indicates both_indicate (Type is String)
        • flag_values: 0, 1, 2, 3 (Type is Int8)
        • valid_min: 0 (Type is Int8)
        • valid_max: 3 (Type is Int8)
    • n_seg_ph[ 0..24] (Type is Int32)
      • attributes
        • units: 1 (Type is String)
        • long_name: number of photons (Type is String)
        • description: Number of photons within each land segment. (Type is String)
        • source: Derived (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
    • terrain_flg[ 0..24] (Type is Int32)
      • attributes
        • _FillValue: 2147483647 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: terrain flag (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)
        • source: Land ATBD section 2.4.8 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: below_threshold above_threshold (Type is String)
        • flag_values: 0, 1 (Type is Int32)
    • urban_flag[ 0..24] (Type is Int32)
      • attributes
        • _FillValue: 2147483647 (Type is Int32)
        • units: 1 (Type is String)
        • long_name: segment urban flag (Type is String)
        • description: The urban flag indicates that a segment is likely located over an urban area. (Type is String)
        • source: Land ATBD section 2.4.17 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: not_urban urban (Type is String)
        • flag_values: 0, 1 (Type is Int32)
    • dem_removal_flag[ 0..24] (Type is Int8)
      • attributes
        • units: 1 (Type is String)
        • long_name: dem removal flag (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)
        • source: ATBD section 2.4.11 (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • flag_meanings: below_threshold above_threshold (Type is String)
        • flag_values: 0, 1 (Type is Int8)
    • h_dif_ref[ 0..24] (Type is Float32)
      • attributes
        • _FillValue: 3.402823466e+38 (Type is Float32)
        • units: meters (Type is String)
        • long_name: h dif from reference (Type is String)
        • description: Difference between h_te_median and ref_DEM (Type is String)
        • source: Land ATBD section 2.4 (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[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: height canopy (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)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_rh_conf[ 0..24] (Type is Int8)
        • attributes
          • units: 1 (Type is String)
          • contentType: modelResult (Type is String)
          • long_name: canopy relative height confidence (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)
          • source: Land/Veg ATBD 13March2019, Section 2.2.21 (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)
          • valid_min: 0 (Type is Int8)
          • valid_max: 2 (Type is Int8)
      • h_median_canopy_abs[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute segment median canopy height (Type is String)
          • description: The median of individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.6 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_min_canopy[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: minimum canopy height (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)
          • source: Land ATBD section 2.2.10 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_mean_canopy_abs[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute mean canopy height (Type is String)
          • description: Mean of the individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.4 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_median_canopy[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: median canopy height (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)
          • source: Land ATBD section 2.2.8 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_canopy_abs[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute segment canopy height (Type is String)
          • description: The 98% height of all the absolute individual canopy heights referenced above the WGS84 ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.2 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • toc_roughness[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: top of canopy roughness (Type is String)
          • description: Standard deviation of the relative heights of all photons classified as top of canopy within the segment (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_min_canopy_abs[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute minimum canopy height (Type is String)
          • description: The minimum of absolute individual canopy heights within segment referenced above the WGS84 Ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.9 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_dif_canopy[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: canopy diff to median height (Type is String)
          • description: Difference between h_canopy and h_median_canopy (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_canopy_quad[ 0..24] (Type is Float32)
        • attributes
          • long_name: canopy quadratic mean (Type is String)
          • description: The quadratic mean height of individual classified relative canopy photon heights above the estimated terrain surface. (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
      • n_ca_photons[ 0..24] (Type is Int32)
        • attributes
          • units: 1 (Type is String)
          • long_name: number canopy photons (Type is String)
          • description: The number of photons classified as canopy within the segment. (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • centroid_height[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: centroid height (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)
          • source: Land ATBD section 2.2.22 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_h_metrics_abs[ 0..24] [ 0..8] (Type is Float32)
        • attributes
          • long_name: canopy absolute height metrics (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: 25,50,60,70,75,80,85,90,95%. (Type is String)
          • source: Land ATBD section 2.2.3 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
      • landsat_perc[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: 1 (Type is String)
          • long_name: landsat percentage canopy (Type is String)
          • description: Average percentage value of the valid (value <= 100) Landsat Tree Cover Continuous Fields product for each 100 m segment (Type is String)
          • source: Land ATBD section 2.2.24 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_mean_canopy[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: mean canopy height (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)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_h_metrics[ 0..24] [ 0..8] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: canopy height metrics (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: 25,50,60,70,75,80,85,90,95%. (Type is String)
          • source: Land ATBD section 2.2.3 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • n_toc_photons[ 0..24] (Type is Int32)
        • attributes
          • units: 1 (Type is String)
          • long_name: number top of canopy photons (Type is String)
          • description: The number of photons classified as top of canopy within the segment. (Type is String)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_flag[ 0..24] (Type is Int32)
        • attributes
          • _FillValue: 2147483647 (Type is Int32)
          • units: 1 (Type is String)
          • long_name: canopy flag (Type is String)
          • description: Flag indicating that canopy was detected using the Landsat Tree Cover Continuous Fields data product. If percent of canopy cover along the L-km segment is greater than 5%, then canopy is assumed to be present; else, no canopy is assumed present. (Type is String)
          • source: Land ATBD section 2.2.22 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • flag_meanings: no_canopy_present canopy_present (Type is String)
          • flag_values: 0, 1 (Type is Int32)
      • landsat_flag[ 0..24] (Type is Int32)
        • attributes
          • _FillValue: 2147483647 (Type is Int32)
          • units: 1 (Type is String)
          • long_name: landsat flag (Type is String)
          • description: Flag indicating that more than 50% of the Landsat Continuous Cover product have values > 100 for the L-Km segment. Canopy is assumed present along the L-km segment if landsat_flag is 1. (Type is String)
          • source: Land ATBD section 2.2.25 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • flag_meanings: canopy_not_assumed_present canopy_assumed_present (Type is String)
          • flag_values: 0, 1 (Type is Int32)
      • h_max_canopy_abs[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: absolute maximum canopy height (Type is String)
          • description: Maximum of individual absolute canopy heights within segment referenced above the WGS84 ellipsoid. (Type is String)
          • source: Land ATBD section 2.2.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_canopy_uncertainty[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: segment canopy height uncertainty (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 in the Land ATBD (Type is String)
          • source: Land ATBD section 1.5 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • canopy_openness[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: 1 (Type is String)
          • long_name: canopy openness (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)
          • source: Land ATBD section 4.12 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_max_canopy[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: maximum canopy height (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)
          • source: Land ATBD section 2.2.12 (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[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: uncertainty of h_te_mean (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 (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_mean[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: mean terrain height (Type is String)
          • description: The mean of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_min[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: minimum terrain height (Type is String)
          • description: The minimum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_interp[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: interpolated terrain surface height (Type is String)
          • description: Interpolated terrain surface height above the WGS84 Ellipsoid at the midpoint of the segment. (Type is String)
          • source: Land ATBD section 4.9 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_max[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: maximum terrain height (Type is String)
          • description: The maximum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_skew[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: skew of terrain heights (Type is String)
          • description: The skewness of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_median[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: median terrain height (Type is String)
          • description: The median of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_best_fit[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: segment terrain height best fit (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)
          • source: Land ATBD section 2.1.15 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_std[ 0..24] (Type is Float32)
        • attributes
          • long_name: segment terrain roughness (Type is String)
          • description: The standard deviation of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
      • terrain_slope[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: 1 (Type is String)
          • long_name: segment terrain slope (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)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • n_te_photons[ 0..24] (Type is Int32)
        • attributes
          • units: 1 (Type is String)
          • long_name: number of ground photons (Type is String)
          • description: The number of the photons classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
      • h_te_mode[ 0..24] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • units: meters (Type is String)
          • long_name: mode of terrain heights (Type is String)
          • description: The mode of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment. (Type is String)
          • source: Land ATBD section 4.11 (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
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