DAP4 Data Request Form ATL07-01_20181014000347_02350101_003_02.h5

dataset: ATL07-01_20181014000347_02350101_003_02.h5
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Global Attributes
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    • Conventions: CF-1.6 (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)
    • date_type: UTC (Type is String)
    • description: The data set (ATL07) contains along-track heights for sea ice and open water leads (at varying length scales) relative to the WGS84 ellipsoid (ITRF2014 reference frame) after adjustment for geoidal and tidal variations, and inverted barometer effects. Heig (Type is String)
    • featureType: trajectory (Type is String)
    • geospatial_lat_units: degrees_north (Type is String)
    • geospatial_lon_units: degrees_east (Type is String)
    • granule_type: ATL07 (Type is String)
    • identifier_product_doi_authority: http://dx.doi.org (Type is String)
    • level: L3A (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)
    • short_name: ATL07 (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)
    • title: SET_BY_META (Type is String)
    • date_created: 2020-05-29T14:35:54.000000Z (Type is String)
    • hdfversion: HDF5 1.10.3 (Type is String)
    • history: 2020-05-29T14:35:54.000000Z;2bed11f8-37e3-3547-bf60-9d7af1919f0d;Created by PGE atlas_l3a_si Version 4.3.2 (Type is String)
    • identifier_file_uuid: 2bed11f8-37e3-3547-bf60-9d7af1919f0d (Type is String)
    • identifier_product_format_version: 4.3 (Type is String)
    • time_coverage_duration: 5658. (Type is Float64)
    • time_coverage_end: 2018-10-14T01:38:05.000000Z (Type is String)
    • time_coverage_start: 2018-10-14T00:03:47.000000Z (Type is String)
    • geospatial_lat_min: 68.916474823665695 (Type is Float64)
    • geospatial_lon_min: 63.30432580191718 (Type is Float64)
    • geospatial_lat_max: 88.043374802950964 (Type is Float64)
    • geospatial_lon_max: -136.62047583959989 (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)
    • identifier_product_type: ATL07 (Type is String)
    • identifier_product_doi: doi:10.5067/ATLAS/ATL07.003 (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 ATL07 is to provide along-track sea ice heights and associated statistics. (Type is String)
    • keywords: EARTH SCIENCE > SPECTRAL/ENGINEERING > LIDAR > LIDAR BACKSCATTER > 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: 2A (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
orbit_info(Type is Group)
  • attributes
    • Description: Contains orbit information. (Type is String)
    • data_rate: Varies. Data are only provided when one of the stored values (besides time) changes. (Type is String)
Dimensions: [ /orbit_info/crossing_time = 0..0 ] [ /orbit_info/sc_orient_time = 0..0 ]
  • crossing_time[ /orbit_info/crossing_time= 0..0] (Type is Float64)
    • attributes
      • contentType: referenceInformation (Type is String)
      • description: The time, in seconds since the ATLAS SDP GPS Epoch, at which the ascending node crosses the equator. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
      • long_name: Ascending Node Crossing Time (Type is String)
      • source: POD/PPD (Type is String)
      • standard_name: time (Type is String)
      • units: seconds since 2018-01-01 (Type is String)
  • sc_orient_time[ /orbit_info/sc_orient_time= 0..0] (Type is Float64)
    • attributes
      • contentType: referenceInformation (Type is String)
      • description: The time of the last spacecraft orientation change between forward, backward and transitional flight modes, expressed in seconds since the ATLAS SDP GPS Epoch. ICESat-2 is considered to be flying forward when the weak beams are leading the strong beams; and backward when the strong beams are leading the weak beams. ICESat-2 is considered to be in transition while it is maneuvering between the two orientations. Science quality is potentially degraded while in transition mode. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
      • long_name: Time of Last Spacecraft Orientation Change (Type is String)
      • source: POD/PPD (Type is String)
      • standard_name: time (Type is String)
      • units: seconds since 2018-01-01 (Type is String)
  • orbit_number[ /orbit_info/crossing_time= 0..0] (Type is UInt16)
    • attributes
      • contentType: referenceInformation (Type is String)
      • coordinates: crossing_time (Type is String)
      • description: Unique identifying number for each planned ICESat-2 orbit. (Type is String)
      • long_name: Orbit Number (Type is String)
      • source: Operations (Type is String)
      • units: 1 (Type is String)
      • valid_max: 65000 (Type is UInt16)
      • valid_min: 1 (Type is UInt16)
  • rgt[ /orbit_info/crossing_time= 0..0] (Type is Int16)
    • attributes
      • contentType: referenceInformation (Type is String)
      • coordinates: crossing_time (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)
      • long_name: Reference Ground track (Type is String)
      • source: POD/PPD (Type is String)
      • units: 1 (Type is String)
      • valid_max: 1387 (Type is Int16)
      • valid_min: 1 (Type is Int16)
  • sc_orient[ /orbit_info/sc_orient_time= 0..0] (Type is Int8)
    • attributes
      • contentType: referenceInformation (Type is String)
      • coordinates: sc_orient_time (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)
      • flag_meanings: backward forward transition (Type is String)
      • flag_values: 0, 1, 2 (Type is Int8)
      • long_name: Spacecraft Orientation (Type is String)
      • source: POD/PPD (Type is String)
      • units: 1 (Type is String)
      • valid_max: 2 (Type is Int8)
      • valid_min: 0 (Type is Int8)
  • cycle_number[ /orbit_info/crossing_time= 0..0] (Type is Int8)
    • attributes
      • contentType: referenceInformation (Type is String)
      • coordinates: crossing_time (Type is String)
      • description: A count of the number of exact repeats of this reference orbit. (Type is String)
      • long_name: Cycle Number (Type is String)
      • source: Operations (Type is String)
      • units: 1 (Type is String)
      • valid_max: 50 (Type is Int8)
      • valid_min: 0 (Type is Int8)
  • lan[ /orbit_info/crossing_time= 0..0] (Type is Float64)
    • attributes
      • contentType: referenceInformation (Type is String)
      • coordinates: crossing_time (Type is String)
      • description: Longitude at the ascending node crossing. (Type is String)
      • long_name: Ascending Node Longitude (Type is String)
      • source: POD/PPD (Type is String)
      • units: degrees_east (Type is String)
      • valid_max: 180. (Type is Float64)
      • valid_min: -180. (Type is Float64)
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>ATL07-01_20181014000347_02350101_003_02.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>2020-05-29T14:35:54.000000Z</gco:DateTime> </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 19115-2:2009-02-15</gco:CharacterString> </gmd:metadataStandardVersion> <gmd:identificationInfo> <gmd:MD_DataIdentification> <gmd:citation> <gmd:CI_Citation> <gmd:title> <gmx:FileName>ATL07-01_20181014000347_02350101_003_02.h5</gmx:FileName> </gmd:title> <gmd:date> <gmd:CI_Date> <gmd:date> <gco:DateTime>2020-05-29T14:35:54.000000Z</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>ATL07</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>003</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>ATL07-01_20181014000347_02350101_003_02.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 ATL07 standard data product contains along-track heights of sea ice and open water leads (at varying length scales) relative to ellipsoid after adjustment for geoida l and tidal variations, and inverted barometer effects. Includes height statistics and apparent reflectance.</gco:CharacterString> </gmd:abstract> <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:aggregationInfo> <gmd:MD_AggregateInformation> <gmd:aggregateDataSetName> <gmd:CI_Citation> <gmd:title> <gco:CharacterString>ATL07</gco:CharacterString> </gmd:title> <gmd:date gco:nilReason="unknown"/> <gmd:edition> <gco:CharacterString>003</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:topicCategory> <gmd:MD_TopicCategoryCode>geoscientificInformation</gmd:MD_TopicCategoryCode> </gmd:topicCategory> <gmd:extent> <gmd:EX_Extent id="boundingExtent"> <gmd:geographicElement> <gmd:EX_GeographicDescription id="Orbit"> <gmd:geographicIdentifier> <gmd:MD_Identifier> <gmd:code> <gco:CharacterString>AscendingCrossing: -127.04822056072560 StartLatitude: 27.000000000000000 StartDirection:A EndLatitude: 27.000000000000000 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: 436 EquatorCrossingLongitude: -127.04822056072560 EquatorCrossingDateTime: 2018-10-14T00:03:47.381163Z</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>2018-10-14T00:21:48.398512Z</gml:beginPosition> <gml:endPosition>2018-10-14T00:29:02.217009Z</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>2020-05-29T14:35:54.000000Z;2bed11f8-37e3-3547-bf60-9d7af1919f0d;Created by PGE atlas_l3a_si Version 4.3.2</gco:CharacterString> </gmd:description> <gmd:dateTime> <gco:DateTime>2020-05-29T14:35:54.000000Z</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>ATL07.003</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 L2A Normalized Relative Backscatter Profiles</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>003</gco:CharacterString> </gmd:edition> <gmd:identifier> <gmd:MD_Identifier> <!-- ECS extracts the ShortName from here --> <gmd:code> <gco:CharacterString>ATL07</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>003</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="https://doi.org/10.5067/ATLAS/ATL07.003">doi:10.5067/ATLAS/ATL07.003</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 ATL07 standard data product contains along-track heights of sea ice and open water leads (at varying length scales) relative to ellipsoid after adjustment for geoidal an d tidal variations, and inverted barometer effects. Includes height statistics and apparent reflectance.</gco:CharacterString> </gmd:abstract> <gmd:purpose> <gco:CharacterString>The purpose of ATL07 is to provide along-track sea ice heights and associated statistics.</gco:CharacterString> </gmd:purpose> <gmd:credit> <gco:CharacterString>The software that generates the ATL07 product was designed and implemented within the ICESat-2 Science Investigator-led Processing System at the NASA Goddard Space Flight Center in G reenbelt, 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; SPECTRAL/ENGINEERING &gt; LIDAR &gt; LIDAR BACKSCATTER &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> <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: 1.0 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>2A</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>2A</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>https://doi.org/10.5067/ATLAS/ATL07.003</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
      • ShortName: ATL07_SDP (Type is String)
      • characterSet: utf8 (Type is String)
      • edition: v4.3 (Type is String)
      • language: eng (Type is String)
      • publicationDate: Feb 2020 (Type is String)
      • title: ICESat-2-SIPS-SPEC-4261 - ATLAS Science Algorithm Standard Data Product (SDP) Volume 6 (ATL07). (Type is String)
  • SeriesIdentification(Type is Group)
    • attributes
      • maintenanceAndUpdateFrequency: asNeeded (Type is String)
      • maintenanceDate: SET_BY_META (Type is String)
      • VersionID: 003 (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 L2A Normalized Relative Backscatter Profiles (Type is String)
      • shortName: ATL07 (Type is String)
      • identifier_product_DOI: doi:10.5067/ATLAS/ATL07.003 (Type is String)
      • revisionDate: 2016-06-09 (Type is String)
      • resourceProviderOrganizationName: National Aeronautics and Space Administration (NASA) (Type is String)
      • abstract: The ICESat-2 ATL07 standard data product contains along-track heights of sea ice and open water leads (at varying length scales) relative to ellipsoid after adjustment for geoidal an d tidal variations, and inverted barometer effects. Includes height statistics and apparent reflectance. (Type is String)
      • purpose: The purpose of ATL07 is to provide along-track sea ice heights and associated statistics. (Type is String)
      • credit: The software that generates the ATL07 product was designed and implemented within the ICESat-2 Science Investigator-led Processing System at the NASA Goddard Space Flight Center in G reenbelt, 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: 2020-05-29T14:35:54.000000Z (Type is String)
      • uuid: 2bed11f8-37e3-3547-bf60-9d7af1919f0d (Type is String)
      • fileName: ATL07-01_20181014000347_02350101_003_02.h5 (Type is String)
      • VersionID: 003 (Type is String)
      • language: eng (Type is String)
      • characterSet: utf8 (Type is String)
      • shortName: ATL07 (Type is String)
      • originatorOrganizationName: GSFC I-SIPS > ICESat-2 Science Investigator-led Processing System (Type is String)
      • abstract: The ICESat-2 ATL07 standard data product contains along-track heights of sea ice and open water leads (at varying length scales) relative to ellipsoid after adjustment for geoidal an d tidal variations, and inverted barometer effects. Includes height statistics and apparent reflectance. (Type is String)
      • purpose: The purpose of ATL07 is to provide along-track sea ice heights and associated statistics. (Type is String)
      • credit: The software that generates the ATL07 product was designed and implemented within the ICESat-2 Science Investigator-led Processing System at the NASA Goddard Space Flight Center in G reenbelt, Maryland. (Type is String)
      • status: onGoing (Type is String)
      • topicCategory: geoscientificInformation (Type is String)
  • Extent(Type is Group)
    • attributes
      • northBoundLatitude: 88.043374802950964 (Type is Float64)
      • eastBoundLongitude: -136.62047583959989 (Type is Float64)
      • southBoundLatitude: 68.916474823665695 (Type is Float64)
      • westBoundLongitude: 63.30432580191718 (Type is Float64)
      • rangeBeginningDateTime: 2018-10-14T00:21:48.398512Z (Type is String)
      • rangeEndingDateTime: 2018-10-14T00:29:02.217009Z (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: 2020-05-29T17:45:40.000000Z (Type is String)
      • fileName: ATL07-01_20181014000347_02350101_003_02.qa (Type is String)
  • Lineage(Type is Group)
    no attributes
    • ANC38-07(Type is Group)
      • attributes
        • description: ISO 19139 XML file containing DataSet-level metadata information. (Type is String)
        • fileName: ANC38-07_20200311164501_003_01.xml (Type is String)
        • shortName: ANC38-07 (Type is String)
        • uuid: 4f41aebb-fa0d-378a-b628-0532fe8b6a67 (Type is String)
        • version: 003 (Type is String)
    • 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_si_004157211.ctl (Type is String)
        • shortName: CNTL (Type is String)
        • version: 1 (Type is String)
    • ANC02-02(Type is Group)
      • attributes
        • description: Sea Ice height correction for skew table file provided by Sea Ice ATBD lead. This is for ASAS version 3 release but in future will become a dynamic file computed based on the impulse response on ATL03 (Type is String)
        • fileName: htcorr_2gauss_convolve.dat (Type is String)
        • shortName: ANC02-02 (Type is String)
        • uuid: d1568221-bfd4-3e58-90ef-a212c3297d17 (Type is String)
        • version: 001 (Type is String)
    • ANC25-07(Type is Group)
      • attributes
        • description: HDF5 template file that defines the organization and default content of the product. (Type is String)
        • fileName: ANC25-07_20200311165637_043_01.h5 (Type is String)
        • shortName: ANC25-07 (Type is String)
        • uuid: 27cc9374-7a28-3d87-93b5-5c8aa490f471 (Type is String)
        • version: 043 (Type is String)
    • ANC15(Type is Group)
      • attributes
        • description: Mean Dynamic Ocean Topography file provided by Sea Ice ATBD lead. (Type is String)
        • fileName: mss_arctic_20190715.2.5km (Type is String)
        • shortName: ANC15 (Type is String)
        • uuid: 011eeff8-50fd-36bf-8de1-36d86990b5e6 (Type is String)
        • version: 20190715 (Type is String)
    • ANC26-07(Type is Group)
      • attributes
        • description: HDF5 template file that defines the organization and default content of the product metadata. (Type is String)
        • fileName: ANC26-07_20200311165645_043_01.h5 (Type is String)
        • shortName: ANC26-07 (Type is String)
        • uuid: 3140c36b-6508-3ff0-b8f9-b605459c87ba (Type is String)
        • version: 043 (Type is String)
    • ANC36-07(Type is Group)
      • attributes
        • description: ISO 19139 XML file containing Series-level metadata information. (Type is String)
        • fileName: ANC36-07_20200311164459_003_01.xml (Type is String)
        • shortName: ANC36-07 (Type is String)
        • uuid: 72e6a080-17e9-3fcf-8a25-b1d9a9fe8fa1 (Type is String)
        • version: 003 (Type is String)
    • ATL03(Type is Group)
      • attributes
        • description: ICESat-2 ATLAS L2A Global Geolocated Photon data products. (Type is String)
        • fileName: ATL03_20181014001049_02350102_003_01.h5, ATL03_20181014001920_02350103_003_01.h5, ATL03_20181014002445_02350104_003_01.h5, ATL03_20181014002954_02350105_003_01.h5 (Type is String)
        • shortName: ATL03, ATL03, ATL03, ATL03 (Type is String)
        • uuid: b611ccb1-aa66-327a-b9cc-8c234051dd4c, 1a9bd4ee-b9b2-3b47-9614-d8e214e18fe1, 6424759e-1924-37bf-8def-9c00e78de775, 807bef11-720f-376b-9905-2b3f947fa7bf (Type is String)
        • version: 003, 003, 003, 003 (Type is String)
        • start_cycle: 1, 1, 1, 1 (Type is Int32)
        • end_cycle: 1, 1, 1, 1 (Type is Int32)
        • start_orbit: 436, 436, 436, 436 (Type is Int32)
        • end_orbit: 436, 436, 436, 436 (Type is Int32)
        • start_rgt: 235, 235, 235, 235 (Type is Int32)
        • end_rgt: 235, 235, 235, 235 (Type is Int32)
        • start_region: 2, 3, 4, 5 (Type is Int32)
        • end_region: 2, 3, 4, 5 (Type is Int32)
        • start_geoseg: 149697, 330711, 446036, 555725 (Type is Int32)
        • end_geoseg: 330710, 446035, 555724, 671052 (Type is Int32)
    • ATL09(Type is Group)
      • attributes
        • description: ICESat-2 ATLAS L3A atmosphere data products. (Type is String)
        • fileName: ATL09_20181014000347_02350101_003_01.h5 (Type is String)
        • shortName: ATL09 (Type is String)
        • uuid: 5eed3d7d-4915-3233-9a69-2998067566d9 (Type is String)
        • version: 003 (Type is String)
        • start_cycle: 1 (Type is Int32)
        • end_cycle: 1 (Type is Int32)
        • start_orbit: 436 (Type is Int32)
        • end_orbit: 436 (Type is Int32)
        • start_rgt: 235 (Type is Int32)
        • end_rgt: 235 (Type is Int32)
        • start_region: 1 (Type is Int32)
        • end_region: 14 (Type is Int32)
        • start_geoseg: 11 (Type is Int32)
        • end_geoseg: 2007120 (Type is Int32)
    • ANC31(Type is Group)
      • attributes
        • description: Sea Ice Concentration file (Type is String)
        • fileName: seaice_conc_daily_icdr_nh_f18_20181014_v01r00.nc (Type is String)
        • shortName: ANC31 (Type is String)
        • uuid: 5bcdc4d3-8815-344d-939a-2e50a56c09a9 (Type is String)
        • version: nc (Type is String)
    • ANC19(Type is Group)
      • attributes
        • description: TAI to UTC leapsecond file retrieved from ftp://maia.usno.navy.mil/ser7/tai-utc.dat (Type is String)
        • fileName: tai_utc_2017.dat (Type is String)
        • shortName: ANC19 (Type is String)
        • uuid: 7c66d365-278a-31f7-8fe4-9c80e2f012e5 (Type is String)
        • version: 001 (Type is String)
  • 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 2.3 (Type is String)
        • softwareDate: Feb 14 2020 (Type is String)
        • softwareTitle: Creates ATLAS HDF5 browse files (Type is String)
        • runTimeParameters: CTL_atlas_l3a_si_004157211.ctl (Type is String)
        • stepDateTime: 2020-05-29T17:45:54.000000Z (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 4.3 (Type is String)
        • softwareDate: Feb 3 2020 (Type is String)
        • softwareTitle: Creates ATLAS XML metadata files (Type is String)
        • runTimeParameters: CTL_atlas_l3a_si_004157211.ctl (Type is String)
        • stepDateTime: 2020-05-29T17:47:04.000000Z (Type is String)
    • PGE(Type is Group)
      • attributes
        • ATBDDate: 12/04/2019 (Type is String)
        • ATBDTitle: Algorithm Theoretical Basis Document (ATBD) For Sea Ice Products (Type is String)
        • ATBDVersion: N/A (Type is String)
        • documentDate: Feb 2020 (Type is String)
        • documentation: ATLAS Science Algorithm Software Design Description (SDD) - Volume 10 (atlas_l3a_si) (Type is String)
        • processDescription: Computes eights of sea ice and open water leads (at varying length scales) relative to ellipsoid after adjusted for geoidal and tidal variations, and inverted barometer effects. Includes height statistics and apparent reflectance. (Type is String)
        • identifier: atlas_l3a_si (Type is String)
        • softwareVersion: Version 4.3.2 (Type is String)
        • softwareDate: May 22 2020 (Type is String)
        • softwareTitle: ASAS L3A Sea Ice PGE (Type is String)
        • runTimeParameters: CTL_atlas_l3a_si_004157211.ctl (Type is String)
        • stepDateTime: 2020-05-29T14:35:54.000000Z (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: atl07_qa_util (Type is String)
        • softwareVersion: Version 4.3 (Type is String)
        • softwareDate: Feb 3 2020 (Type is String)
        • softwareTitle: ATL07 QA Utility (Type is String)
        • runTimeParameters: CTL_atlas_l3a_si_004157211.ctl (Type is String)
        • stepDateTime: 2020-05-29T17:45:40.000000Z (Type is String)
gt1r(Type is Group)
  • attributes
    • Description: This ground contains parameters and subgroups related a specific groundtrack. (Type is String)
    • data_rate: Each subgroup identifies its particular data rate. (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)
  • sea_ice_segments(Type is Group)
    • attributes
      • Description: Top group for sea ice segments as computed by the ATBD aglorithm (Type is String)
      • data_rate: Data within this group are stored at the variable segment rate. (Type is String)
    Dimensions: [ /gt1r/sea_ice_segments/delta_time = 0..280132 ]
    • latitude[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time longitude (Type is String)
        • description: Latitude, WGS84, North=+, Lat of segment center (Type is String)
        • long_name: Latitude (Type is String)
        • source: ATBD, section 4.4 (Type is String)
        • standard_name: latitude (Type is String)
        • units: degrees_north (Type is String)
        • valid_max: 90. (Type is Float64)
        • valid_min: -90. (Type is Float64)
    • delta_time[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float64)
      • attributes
        • contentType: physicalMeasurement (Type is String)
        • coordinates: latitude longitude (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)
        • long_name: Elapsed GPS seconds (Type is String)
        • source: telemetry (Type is String)
        • standard_name: time (Type is String)
        • units: seconds since 2018-01-01 (Type is String)
    • longitude[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude (Type is String)
        • description: Longitude, WGS84, East=+,Lon of segment center (Type is String)
        • long_name: Longitude (Type is String)
        • source: ATBD, section 4.4 (Type is String)
        • standard_name: longitude (Type is String)
        • units: degrees_east (Type is String)
        • valid_max: 180. (Type is Float64)
        • valid_min: -180. (Type is Float64)
    • height_segment_id[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Identifier of each height segment (Type is String)
        • long_name: Identifier of each height segment (Type is String)
        • source: ATBD, section 5.2 (Type is String)
        • units: 1 (Type is String)
    • geoseg_beg[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Geolocation segment (geoseg) ID associated with the first photon used in this sea ice segment (Type is String)
        • long_name: Beginning GEOSEG (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • seg_dist_x[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Along-track distance from the equator crossing to the segment center. (Type is String)
        • long_name: Along track distance (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • geoseg_end[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Geolocation segment (geoseg) ID associated with the last photon used in this sea ice segment (Type is String)
        • long_name: Ending GEOSEG (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • heights(Type is Group)
      • attributes
        • Description: Contains parameters relating to the calculated surface height for one Ground Track. As ICESat-2 orbits the earth, sequential transmit pulses illuminate six ground tracks on the surface of the earth. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • height_segment_fit_quality_flag[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Int8)
        • attributes
          • _FillValue: -1 (Type is Int8)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Flag describing the quality of the results of the along-track fit. (-1=height value is invalid; 1=ngrid_w < wlength/2; 2=ngrid_w >= wlength/2; 3=ngrid_dt < dtlength/2; 4=ngrid_dt >= dtlength/2; 5=ngrid_dt >= (dtlength-2): where 1 is best and 5 is poor). Heights are reported even if this flag indicates the height is invalid. (Type is String)
          • flag_meanings: invalid best high med low poor (Type is String)
          • flag_values: -1, 1, 2, 3, 4, 5 (Type is Int8)
          • long_name: height Quality Flag (Type is String)
          • source: ATBD, section 4.2.4.2 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 5 (Type is Int8)
          • valid_min: -1 (Type is Int8)
      • height_segment_length_seg[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: along-track length of segment containing n_photons_actual (Type is String)
          • long_name: length of segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_asr_calc[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Computed apparent surface reflectance for the sea ice segment. (Type is String)
          • long_name: Calculated Apparent Surface Reflectivity (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • height_segment_quality[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Height segment quality flag, 1 is good quality, 0 is bad depending on fit, wguassian, or layer flag (Type is String)
          • flag_meanings: bad_quality good_quality (Type is String)
          • flag_values: 0, 1 (Type is Int8)
          • long_name: Height Segment Quality Flag (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_n_pulse_seg[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Int32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: number of laser pulses (Type is String)
          • long_name: number of laser pulses (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • across_track_distance[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Across track distance of photons averaged over the sea ice height segment. (Type is String)
          • long_name: Across Track Distance (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_htcorr_skew[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height corection for skew (Type is String)
          • long_name: Height Correction for Skew (Type is String)
          • source: ATBD, section 4.2.6 (Type is String)
          • units: meters (Type is String)
      • height_segment_ssh_flag[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Identifies the height segments that are candidates for use as sea surface reference in freeboard calculations in ATL10. 0 = sea ice; 1 = sea surface (Type is String)
          • flag_meanings: sea_ice sea_surface (Type is String)
          • flag_values: 0, 1 (Type is Int8)
          • long_name: Sea Surface Flag (Type is String)
          • source: ATBD, section 4.3 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_height[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean height from along-track segment fit detremined by the sea ice algorithm (Type is String)
          • long_name: height of segment surface (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
      • height_segment_type[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Value that indicates segment surface type as sea ice or different types of sea surface. 0=cloud covered: rsurf (Type is String)
          • flag_meanings: cloud_covered other specular_lead_low_w_bkg specular_lead_low specular_lead_high_w_bkg specular_lead_high dark_lead_smooth_w_bkg dark_lead_smooth dark_lead_rough_w_bkg dark_lead_rough (Type is String)
          • flag_values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 (Type is Int8)
          • long_name: Segment surface type (Type is String)
          • source: ATBD, section 4.3 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 9 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_confidence[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Confidence level in the surface height estimate based on the number of photons; the background noise rate; and the error analysis (Type is String)
          • long_name: Surface height confidence (Type is String)
          • source: ATBD, section 4.2.4.2 (Type is String)
          • units: 1 (Type is String)
      • height_segment_surface_error_est[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Error estimate of the surface height (Type is String)
          • long_name: h surface error est (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_w_gaussian[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: width of best fit gaussian (Type is String)
          • long_name: width of best fit gaussian (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_rms[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: RMS difference between sea ice modeled and observed photon height distribution (Type is String)
          • long_name: height rms (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
    • geophysical(Type is Group)
      • attributes
        • Description: Contains geophysical parameters and corrections used to correct photon heights for geophysical effects, such as tides. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • height_segment_t2m[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Temperature at 2m above the displacement height (K) (Type is String)
          • long_name: temperature_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: temperature (Type is String)
          • units: K (Type is String)
      • height_segment_dac[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect. (Type is String)
          • long_name: Dynamic Atmosphere Correction (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_ps[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Sea Level Pressure (Pa) (Type is String)
          • long_name: sea level pressure (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: pressure (Type is String)
          • units: Pa (Type is String)
      • height_segment_ib[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Inverted barometer effect calculated from surface pressure (Type is String)
          • long_name: Inverted barometer effect (Type is String)
          • source: ATBD, section 4.2 (Type is String)
          • units: meters (Type is String)
      • height_segment_load[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Load Tide - Local displacement due to Ocean Loading (-6 to 0 cm). (Type is String)
          • long_name: Load Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_geoid[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Geoid height above WGS-84 reference ellipsoid (range -107 to 86m), based on the EGM2008 model. (Type is String)
          • long_name: EGM2008 Geoid (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_ocean[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Ocean Tides including diurnal and semi-diurnal (harmonic analysis), and longer period tides (dynamic and self-consistent equilibrium) (Type is String)
          • long_name: Ocean Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_v2m[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Northward wind at 2m above the displacement height (m/s-1) (Type is String)
          • long_name: Northward_wind_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: northward_wind (Type is String)
          • units: m s-1 (Type is String)
      • height_segment_mss[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean sea surface height above WGS-84 reference ellipsoid (range: -105 to 87m), based on the DTU13 model. (Type is String)
          • long_name: DTU13 Mean Sea Surface (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_u2m[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Eastward wind at 2m above the displacement height (m/s-1) (Type is String)
          • long_name: Eastward_wind_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: eastward_wind (Type is String)
          • units: m s-1 (Type is String)
      • height_segment_lpe[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Long period equilibrium tide self-consistent with ocean tide model (+-0.04m). (dependent only on time and latitude) (Type is String)
          • long_name: Equilibrium Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_earth[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Solid Earth Tide (Type is String)
          • long_name: Earth Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_pole[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Pole Tide -Rotational deformation due to polar motion (-1.5 to 1.5 cm). (Type is String)
          • long_name: Pole Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
    • stats(Type is Group)
      • attributes
        • Description: Contains parameters related to quality and corrections on the sea ice height paramters (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      Dimensions: [ /gt1r/sea_ice_segments/stats/ds_si_hist_bins = 0..220 ]
      • ds_si_hist_bins[ /gt1r/sea_ice_segments/stats/ds_si_hist_bins= 0..220] (Type is Int32)
        • attributes
          • contentType: auxiliaryInformation (Type is String)
          • description: Dimension scale indexing the sea ice histogram bins. The bin heights must be computed from information contained within the same group as the histogram. (Type is String)
          • long_name: Sea Ice Histogram Bins Dimension Scale (Type is String)
          • source: SeaIce ATBD (Type is String)
          • units: 1 (Type is String)
      • hist_median_h[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Median of the n_fit_photons heights (Type is String)
          • long_name: trimmed photon heights median (Type is String)
          • source: ATBD, section 4.2.3.1 (Type is String)
          • units: meters (Type is String)
      • height_filter_min[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height minimum used in the ssh height filter (Type is String)
          • long_name: Height Filter Min (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • cloud_flag_atm[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Int8)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of layers found from the backscatter profile using the DDA layer finder. (Type is String)
          • long_name: Cloud Flag Atm (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 10 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • fpb_avg_dt[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction average dead time (Type is String)
          • long_name: fpb correction average deadtime (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: ns (Type is String)
      • msw_flag[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Int8)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • 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)
          • long_name: Multiple Scattering Warning Flag (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 5 (Type is Int8)
          • valid_min: -1 (Type is Int8)
      • fpb_strength[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction strength (Type is String)
          • long_name: fpb correction strength (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: photons/shot (Type is String)
      • bsnow_con[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Int8)
        • attributes
          • _FillValue: 127 (Type is Int8)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Blowing snow confidence (Type is String)
          • long_name: Blowing snow confidence (Type is String)
          • source: ATL09 (Type is String)
          • units: 1 (Type is String)
      • layer_flag[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Int16)
        • attributes
          • contentType: qualityInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • flag_meanings: likely_clear likely_cloudy (Type is String)
          • flag_values: 0, 1 (Type is Int16)
          • long_name: Consolidated cloud flag (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int16)
          • valid_min: 0 (Type is Int16)
      • hist_photon_bin_size[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: bin size of photon height histogram (Type is String)
          • long_name: height histogram bin size (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • backgr_calc[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Calculated background count rate based on sun angle, surface slope, unit reflectance (Type is String)
          • long_name: background count rate calculated (Type is String)
          • source: ATBD, section 4.2.3 (Type is String)
          • units: hz (Type is String)
      • fpb_corr[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated first-photon bias(fpb) correction to mean segment height (Type is String)
          • long_name: first photon bias correction (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • bsnow_h[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Blowing snow layer top height (Type is String)
          • long_name: Blowing snow top h (Type is String)
          • source: ATL09 (Type is String)
          • units: meters (Type is String)
      • hist_photon_bottom[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: lower bound of height histogram (Type is String)
          • long_name: height histogram minimum (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • background_r_norm[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background rate normalized to a fixed solar elevation angle (Type is String)
          • long_name: Normalized background (50-shot) (Type is String)
          • source: ATBD section 4.3.1.3 (Type is String)
          • units: hz (Type is String)
      • exmax_mean_2[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mean 2 (Type is String)
          • long_name: Exmax Mean 2 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • background_int_height[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: The height of the altimetric range window after subtracting the height span of the signal photon events in the 50-shot span (Type is String)
          • long_name: Height of column used in background calculation (Type is String)
          • source: ATBD, section 7.3 (Type is String)
          • units: meters (Type is String)
      • n_photons_actual[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons gathered (Type is String)
          • long_name: Number of photons found for the segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • ice_conc[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: sea ice concentration (Type is String)
          • long_name: sea ice concentration (Type is String)
          • source: ATBD, section 3.1.4 (Type is String)
          • units: 1 (Type is String)
      • exmax_stdev_2[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height standard deviation 2 (Type is String)
          • long_name: Exmax Stdev 2 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • cloud_flag_asr[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Int16)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Cloud flag (probability) from apparent surface reflectance. 0=clear with high confidence; 1=clear with medium confidence; 2=clear with low confidence; 3=cloudy with low confidence; 4=cloudy with medium confidence; 5=cloudy with high confidence; 6=unknown (Type is String)
          • flag_meanings: clear_with_high_confidence clear_with_medium_confidence clear_with_low_confidence cloudy_with_low_confidence cloudy_with_medium_confidence cloudy_with_high_confidence unknown (Type is String)
          • flag_values: 0, 1, 2, 3, 4, 5, 6 (Type is Int16)
          • long_name: Cloud Flag ASR (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 6 (Type is Int16)
          • valid_min: 0 (Type is Int16)
      • exmax_stdev_1[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height standard deviation 1 (Type is String)
          • long_name: Exmax Stdev 1 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • fpb_corr_width[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction width (Type is String)
          • long_name: fpb correction width (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: ns (Type is String)
      • height_coarse_stdev[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height standard deviation of coarse tracker (Type is String)
          • long_name: Coarse Height Sdev (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • height_filter_05[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height fifth percentile used in the ssh height filter (Type is String)
          • long_name: Height Filter 5th Percentile (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • n_photons_used[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons in the trimmed histogram. (Type is String)
          • long_name: Number of photons used for fit (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • backgr_r_200[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background count rate, averaged over the segment based on ATLAS 50 pulse counts (Type is String)
          • long_name: Background rate 200 hz (Type is String)
          • source: ATL09 (Type is String)
          • units: hz (Type is String)
      • hist_photon_top[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: upper bound of height histogram (Type is String)
          • long_name: height histogram maximum (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • hist_w[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Segment histogram width estimate (Type is String)
          • long_name: Segment histogram width estimate (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • hist_mean_h[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean of the n_fit_photons heights (Type is String)
          • long_name: photon heights mean (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_coarse_mn[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height mean of coarse tracker (Type is String)
          • long_name: Coarse Track Height Mean (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • exmax_mean_1[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mean 1 (Type is String)
          • long_name: Exmax Mean 1 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • hist_photon_heights[ /gt1r/sea_ice_segments/delta_time= 0..280132] [ /gt1r/sea_ice_segments/stats/ds_si_hist_bins= 0..220] (Type is Int16)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Histogram of the n_fit_photons heights (Type is String)
          • long_name: photon heights histogram (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • trim_height_top[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: maximum height of trimmed photons used in the surface calculation procedure (Type is String)
          • long_name: maximum height of trimmed photons (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • exmax_mix[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mix ratio (Type is String)
          • long_name: Exmax Mix (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • asr_25[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Apparent surface reflectance at 25 hz, averaged to the sea ice segment. (Type is String)
          • long_name: Apparent Surface Reflectance 25hz (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • photon_rate[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: photon count rate, averaged over segment (Type is String)
          • long_name: photon rate (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: photons/shot (Type is String)
      • trim_height_bottom[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: minimum height of trimmed photons used in the surface calculation procedure (Type is String)
          • long_name: minimum height of trimmed photons (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • n_photons_define[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons to gather. (Type is String)
          • long_name: Number of photons defining the segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • backgr_r_25[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background count rate, averaged over the segment based on 25 hz atmosphere (Type is String)
          • long_name: Background rate 25hz (Type is String)
          • source: ATL09 (Type is String)
          • units: hz (Type is String)
    • geolocation(Type is Group)
      • attributes
        • Description: Contains parameters related to geolocation. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • rgt[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Int16)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: Reference Ground track (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1387 (Type is Int16)
          • valid_min: 1 (Type is Int16)
      • sigma_lon[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point east longitude: 1- sigma (degrees). Applies to all other photons in the group. (Type is String)
          • long_name: longitude uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (Type is String)
      • ref_atm_delay[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Atmospheric path delay, in range, for the reference photon. (Type is String)
          • long_name: Reference Photon Atm. Path Delay (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • beam_azimuth[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: The direction, eastwards from north, of the laser beam vector as seen by an observer at the laser ground spot viewing toward the spacecraft (i.e., the vector from the ground to the spacecraft). When the spacecraft is precisely at the geodetic zenith, the value will be 99999 degrees. (Type is String)
          • long_name: beam azimuth (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees_east (Type is String)
      • solar_azimuth[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • contentType: physicalMeansurement (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: solar azimuth (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees_east (Type is String)
      • ref_atm_delay_derivative[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Atmospheric path delay derivative with respect to ellipsoid for the reference photon, in meters per meter. (Type is String)
          • long_name: Derivative of Atm. Path Delay (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters/meter (Type is String)
      • sigma_lat[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point geodetic latitude: 1- sigma (degrees). Applies to all other photons in the group (Type is String)
          • long_name: latitude uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • beam_coelev[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: beam co-elevation (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (Type is String)
      • sigma_h[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m). Error estimates for all other photons in the group are computed with the scale defined below. (Type is String)
          • long_name: height uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • solar_elevation[ /gt1r/sea_ice_segments/delta_time= 0..280132] (Type is Float32)
        • attributes
          • contentType: physicalMeansurement (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: solar elevation (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (Type is String)
gt2r(Type is Group)
  • attributes
    • Description: This ground contains parameters and subgroups related a specific groundtrack. (Type is String)
    • data_rate: Each subgroup identifies its particular data rate. (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)
  • sea_ice_segments(Type is Group)
    • attributes
      • Description: Top group for sea ice segments as computed by the ATBD aglorithm (Type is String)
      • data_rate: Data within this group are stored at the variable segment rate. (Type is String)
    Dimensions: [ /gt2r/sea_ice_segments/delta_time = 0..225002 ]
    • latitude[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time longitude (Type is String)
        • description: Latitude, WGS84, North=+, Lat of segment center (Type is String)
        • long_name: Latitude (Type is String)
        • source: ATBD, section 4.4 (Type is String)
        • standard_name: latitude (Type is String)
        • units: degrees_north (Type is String)
        • valid_max: 90. (Type is Float64)
        • valid_min: -90. (Type is Float64)
    • delta_time[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float64)
      • attributes
        • contentType: physicalMeasurement (Type is String)
        • coordinates: latitude longitude (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)
        • long_name: Elapsed GPS seconds (Type is String)
        • source: telemetry (Type is String)
        • standard_name: time (Type is String)
        • units: seconds since 2018-01-01 (Type is String)
    • longitude[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude (Type is String)
        • description: Longitude, WGS84, East=+,Lon of segment center (Type is String)
        • long_name: Longitude (Type is String)
        • source: ATBD, section 4.4 (Type is String)
        • standard_name: longitude (Type is String)
        • units: degrees_east (Type is String)
        • valid_max: 180. (Type is Float64)
        • valid_min: -180. (Type is Float64)
    • height_segment_id[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Identifier of each height segment (Type is String)
        • long_name: Identifier of each height segment (Type is String)
        • source: ATBD, section 5.2 (Type is String)
        • units: 1 (Type is String)
    • geoseg_beg[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Geolocation segment (geoseg) ID associated with the first photon used in this sea ice segment (Type is String)
        • long_name: Beginning GEOSEG (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • seg_dist_x[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Along-track distance from the equator crossing to the segment center. (Type is String)
        • long_name: Along track distance (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • geoseg_end[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Geolocation segment (geoseg) ID associated with the last photon used in this sea ice segment (Type is String)
        • long_name: Ending GEOSEG (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • heights(Type is Group)
      • attributes
        • Description: Contains parameters relating to the calculated surface height for one Ground Track. As ICESat-2 orbits the earth, sequential transmit pulses illuminate six ground tracks on the surface of the earth. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • height_segment_fit_quality_flag[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Int8)
        • attributes
          • _FillValue: -1 (Type is Int8)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Flag describing the quality of the results of the along-track fit. (-1=height value is invalid; 1=ngrid_w < wlength/2; 2=ngrid_w >= wlength/2; 3=ngrid_dt < dtlength/2; 4=ngrid_dt >= dtlength/2; 5=ngrid_dt >= (dtlength-2): where 1 is best and 5 is poor). Heights are reported even if this flag indicates the height is invalid. (Type is String)
          • flag_meanings: invalid best high med low poor (Type is String)
          • flag_values: -1, 1, 2, 3, 4, 5 (Type is Int8)
          • long_name: height Quality Flag (Type is String)
          • source: ATBD, section 4.2.4.2 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 5 (Type is Int8)
          • valid_min: -1 (Type is Int8)
      • height_segment_length_seg[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: along-track length of segment containing n_photons_actual (Type is String)
          • long_name: length of segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_asr_calc[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Computed apparent surface reflectance for the sea ice segment. (Type is String)
          • long_name: Calculated Apparent Surface Reflectivity (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • height_segment_quality[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Height segment quality flag, 1 is good quality, 0 is bad depending on fit, wguassian, or layer flag (Type is String)
          • flag_meanings: bad_quality good_quality (Type is String)
          • flag_values: 0, 1 (Type is Int8)
          • long_name: Height Segment Quality Flag (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_n_pulse_seg[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Int32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: number of laser pulses (Type is String)
          • long_name: number of laser pulses (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • across_track_distance[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Across track distance of photons averaged over the sea ice height segment. (Type is String)
          • long_name: Across Track Distance (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_htcorr_skew[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height corection for skew (Type is String)
          • long_name: Height Correction for Skew (Type is String)
          • source: ATBD, section 4.2.6 (Type is String)
          • units: meters (Type is String)
      • height_segment_ssh_flag[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Identifies the height segments that are candidates for use as sea surface reference in freeboard calculations in ATL10. 0 = sea ice; 1 = sea surface (Type is String)
          • flag_meanings: sea_ice sea_surface (Type is String)
          • flag_values: 0, 1 (Type is Int8)
          • long_name: Sea Surface Flag (Type is String)
          • source: ATBD, section 4.3 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_height[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean height from along-track segment fit detremined by the sea ice algorithm (Type is String)
          • long_name: height of segment surface (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
      • height_segment_type[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Value that indicates segment surface type as sea ice or different types of sea surface. 0=cloud covered: rsurf (Type is String)
          • flag_meanings: cloud_covered other specular_lead_low_w_bkg specular_lead_low specular_lead_high_w_bkg specular_lead_high dark_lead_smooth_w_bkg dark_lead_smooth dark_lead_rough_w_bkg dark_lead_rough (Type is String)
          • flag_values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 (Type is Int8)
          • long_name: Segment surface type (Type is String)
          • source: ATBD, section 4.3 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 9 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_confidence[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Confidence level in the surface height estimate based on the number of photons; the background noise rate; and the error analysis (Type is String)
          • long_name: Surface height confidence (Type is String)
          • source: ATBD, section 4.2.4.2 (Type is String)
          • units: 1 (Type is String)
      • height_segment_surface_error_est[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Error estimate of the surface height (Type is String)
          • long_name: h surface error est (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_w_gaussian[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: width of best fit gaussian (Type is String)
          • long_name: width of best fit gaussian (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_rms[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: RMS difference between sea ice modeled and observed photon height distribution (Type is String)
          • long_name: height rms (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
    • geophysical(Type is Group)
      • attributes
        • Description: Contains geophysical parameters and corrections used to correct photon heights for geophysical effects, such as tides. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • height_segment_t2m[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Temperature at 2m above the displacement height (K) (Type is String)
          • long_name: temperature_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: temperature (Type is String)
          • units: K (Type is String)
      • height_segment_dac[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect. (Type is String)
          • long_name: Dynamic Atmosphere Correction (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_ps[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Sea Level Pressure (Pa) (Type is String)
          • long_name: sea level pressure (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: pressure (Type is String)
          • units: Pa (Type is String)
      • height_segment_ib[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Inverted barometer effect calculated from surface pressure (Type is String)
          • long_name: Inverted barometer effect (Type is String)
          • source: ATBD, section 4.2 (Type is String)
          • units: meters (Type is String)
      • height_segment_load[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Load Tide - Local displacement due to Ocean Loading (-6 to 0 cm). (Type is String)
          • long_name: Load Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_geoid[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Geoid height above WGS-84 reference ellipsoid (range -107 to 86m), based on the EGM2008 model. (Type is String)
          • long_name: EGM2008 Geoid (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_ocean[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Ocean Tides including diurnal and semi-diurnal (harmonic analysis), and longer period tides (dynamic and self-consistent equilibrium) (Type is String)
          • long_name: Ocean Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_v2m[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Northward wind at 2m above the displacement height (m/s-1) (Type is String)
          • long_name: Northward_wind_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: northward_wind (Type is String)
          • units: m s-1 (Type is String)
      • height_segment_mss[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean sea surface height above WGS-84 reference ellipsoid (range: -105 to 87m), based on the DTU13 model. (Type is String)
          • long_name: DTU13 Mean Sea Surface (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_u2m[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Eastward wind at 2m above the displacement height (m/s-1) (Type is String)
          • long_name: Eastward_wind_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: eastward_wind (Type is String)
          • units: m s-1 (Type is String)
      • height_segment_lpe[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Long period equilibrium tide self-consistent with ocean tide model (+-0.04m). (dependent only on time and latitude) (Type is String)
          • long_name: Equilibrium Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_earth[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Solid Earth Tide (Type is String)
          • long_name: Earth Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_pole[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Pole Tide -Rotational deformation due to polar motion (-1.5 to 1.5 cm). (Type is String)
          • long_name: Pole Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
    • stats(Type is Group)
      • attributes
        • Description: Contains parameters related to quality and corrections on the sea ice height paramters (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      Dimensions: [ /gt2r/sea_ice_segments/stats/ds_si_hist_bins = 0..220 ]
      • ds_si_hist_bins[ /gt2r/sea_ice_segments/stats/ds_si_hist_bins= 0..220] (Type is Int32)
        • attributes
          • contentType: auxiliaryInformation (Type is String)
          • description: Dimension scale indexing the sea ice histogram bins. The bin heights must be computed from information contained within the same group as the histogram. (Type is String)
          • long_name: Sea Ice Histogram Bins Dimension Scale (Type is String)
          • source: SeaIce ATBD (Type is String)
          • units: 1 (Type is String)
      • hist_median_h[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Median of the n_fit_photons heights (Type is String)
          • long_name: trimmed photon heights median (Type is String)
          • source: ATBD, section 4.2.3.1 (Type is String)
          • units: meters (Type is String)
      • height_filter_min[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height minimum used in the ssh height filter (Type is String)
          • long_name: Height Filter Min (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • cloud_flag_atm[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Int8)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of layers found from the backscatter profile using the DDA layer finder. (Type is String)
          • long_name: Cloud Flag Atm (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 10 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • fpb_avg_dt[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction average dead time (Type is String)
          • long_name: fpb correction average deadtime (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: ns (Type is String)
      • msw_flag[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Int8)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • 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)
          • long_name: Multiple Scattering Warning Flag (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 5 (Type is Int8)
          • valid_min: -1 (Type is Int8)
      • fpb_strength[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction strength (Type is String)
          • long_name: fpb correction strength (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: photons/shot (Type is String)
      • bsnow_con[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Int8)
        • attributes
          • _FillValue: 127 (Type is Int8)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Blowing snow confidence (Type is String)
          • long_name: Blowing snow confidence (Type is String)
          • source: ATL09 (Type is String)
          • units: 1 (Type is String)
      • layer_flag[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Int16)
        • attributes
          • contentType: qualityInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • flag_meanings: likely_clear likely_cloudy (Type is String)
          • flag_values: 0, 1 (Type is Int16)
          • long_name: Consolidated cloud flag (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int16)
          • valid_min: 0 (Type is Int16)
      • hist_photon_bin_size[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: bin size of photon height histogram (Type is String)
          • long_name: height histogram bin size (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • backgr_calc[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Calculated background count rate based on sun angle, surface slope, unit reflectance (Type is String)
          • long_name: background count rate calculated (Type is String)
          • source: ATBD, section 4.2.3 (Type is String)
          • units: hz (Type is String)
      • fpb_corr[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated first-photon bias(fpb) correction to mean segment height (Type is String)
          • long_name: first photon bias correction (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • bsnow_h[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Blowing snow layer top height (Type is String)
          • long_name: Blowing snow top h (Type is String)
          • source: ATL09 (Type is String)
          • units: meters (Type is String)
      • hist_photon_bottom[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: lower bound of height histogram (Type is String)
          • long_name: height histogram minimum (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • background_r_norm[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background rate normalized to a fixed solar elevation angle (Type is String)
          • long_name: Normalized background (50-shot) (Type is String)
          • source: ATBD section 4.3.1.3 (Type is String)
          • units: hz (Type is String)
      • exmax_mean_2[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mean 2 (Type is String)
          • long_name: Exmax Mean 2 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • background_int_height[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: The height of the altimetric range window after subtracting the height span of the signal photon events in the 50-shot span (Type is String)
          • long_name: Height of column used in background calculation (Type is String)
          • source: ATBD, section 7.3 (Type is String)
          • units: meters (Type is String)
      • n_photons_actual[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons gathered (Type is String)
          • long_name: Number of photons found for the segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • ice_conc[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: sea ice concentration (Type is String)
          • long_name: sea ice concentration (Type is String)
          • source: ATBD, section 3.1.4 (Type is String)
          • units: 1 (Type is String)
      • exmax_stdev_2[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height standard deviation 2 (Type is String)
          • long_name: Exmax Stdev 2 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • cloud_flag_asr[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Int16)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Cloud flag (probability) from apparent surface reflectance. 0=clear with high confidence; 1=clear with medium confidence; 2=clear with low confidence; 3=cloudy with low confidence; 4=cloudy with medium confidence; 5=cloudy with high confidence; 6=unknown (Type is String)
          • flag_meanings: clear_with_high_confidence clear_with_medium_confidence clear_with_low_confidence cloudy_with_low_confidence cloudy_with_medium_confidence cloudy_with_high_confidence unknown (Type is String)
          • flag_values: 0, 1, 2, 3, 4, 5, 6 (Type is Int16)
          • long_name: Cloud Flag ASR (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 6 (Type is Int16)
          • valid_min: 0 (Type is Int16)
      • exmax_stdev_1[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height standard deviation 1 (Type is String)
          • long_name: Exmax Stdev 1 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • fpb_corr_width[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction width (Type is String)
          • long_name: fpb correction width (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: ns (Type is String)
      • height_coarse_stdev[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height standard deviation of coarse tracker (Type is String)
          • long_name: Coarse Height Sdev (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • height_filter_05[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height fifth percentile used in the ssh height filter (Type is String)
          • long_name: Height Filter 5th Percentile (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • n_photons_used[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons in the trimmed histogram. (Type is String)
          • long_name: Number of photons used for fit (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • backgr_r_200[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background count rate, averaged over the segment based on ATLAS 50 pulse counts (Type is String)
          • long_name: Background rate 200 hz (Type is String)
          • source: ATL09 (Type is String)
          • units: hz (Type is String)
      • hist_photon_top[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: upper bound of height histogram (Type is String)
          • long_name: height histogram maximum (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • hist_w[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Segment histogram width estimate (Type is String)
          • long_name: Segment histogram width estimate (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • hist_mean_h[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean of the n_fit_photons heights (Type is String)
          • long_name: photon heights mean (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_coarse_mn[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height mean of coarse tracker (Type is String)
          • long_name: Coarse Track Height Mean (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • exmax_mean_1[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mean 1 (Type is String)
          • long_name: Exmax Mean 1 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • hist_photon_heights[ /gt2r/sea_ice_segments/delta_time= 0..225002] [ /gt2r/sea_ice_segments/stats/ds_si_hist_bins= 0..220] (Type is Int16)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Histogram of the n_fit_photons heights (Type is String)
          • long_name: photon heights histogram (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • trim_height_top[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: maximum height of trimmed photons used in the surface calculation procedure (Type is String)
          • long_name: maximum height of trimmed photons (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • exmax_mix[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mix ratio (Type is String)
          • long_name: Exmax Mix (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • asr_25[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Apparent surface reflectance at 25 hz, averaged to the sea ice segment. (Type is String)
          • long_name: Apparent Surface Reflectance 25hz (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • photon_rate[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: photon count rate, averaged over segment (Type is String)
          • long_name: photon rate (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: photons/shot (Type is String)
      • trim_height_bottom[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: minimum height of trimmed photons used in the surface calculation procedure (Type is String)
          • long_name: minimum height of trimmed photons (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • n_photons_define[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons to gather. (Type is String)
          • long_name: Number of photons defining the segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • backgr_r_25[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background count rate, averaged over the segment based on 25 hz atmosphere (Type is String)
          • long_name: Background rate 25hz (Type is String)
          • source: ATL09 (Type is String)
          • units: hz (Type is String)
    • geolocation(Type is Group)
      • attributes
        • Description: Contains parameters related to geolocation. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • rgt[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Int16)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: Reference Ground track (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1387 (Type is Int16)
          • valid_min: 1 (Type is Int16)
      • sigma_lon[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point east longitude: 1- sigma (degrees). Applies to all other photons in the group. (Type is String)
          • long_name: longitude uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (Type is String)
      • ref_atm_delay[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Atmospheric path delay, in range, for the reference photon. (Type is String)
          • long_name: Reference Photon Atm. Path Delay (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • beam_azimuth[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: The direction, eastwards from north, of the laser beam vector as seen by an observer at the laser ground spot viewing toward the spacecraft (i.e., the vector from the ground to the spacecraft). When the spacecraft is precisely at the geodetic zenith, the value will be 99999 degrees. (Type is String)
          • long_name: beam azimuth (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees_east (Type is String)
      • solar_azimuth[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • contentType: physicalMeansurement (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: solar azimuth (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees_east (Type is String)
      • ref_atm_delay_derivative[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Atmospheric path delay derivative with respect to ellipsoid for the reference photon, in meters per meter. (Type is String)
          • long_name: Derivative of Atm. Path Delay (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters/meter (Type is String)
      • sigma_lat[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point geodetic latitude: 1- sigma (degrees). Applies to all other photons in the group (Type is String)
          • long_name: latitude uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • beam_coelev[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: beam co-elevation (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (Type is String)
      • sigma_h[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m). Error estimates for all other photons in the group are computed with the scale defined below. (Type is String)
          • long_name: height uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • solar_elevation[ /gt2r/sea_ice_segments/delta_time= 0..225002] (Type is Float32)
        • attributes
          • contentType: physicalMeansurement (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: solar elevation (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (Type is String)
gt1l(Type is Group)
  • attributes
    • Description: This ground contains parameters and subgroups related a specific groundtrack. (Type is String)
    • data_rate: Each subgroup identifies its particular data rate. (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)
  • sea_ice_segments(Type is Group)
    • attributes
      • Description: Top group for sea ice segments as computed by the ATBD aglorithm (Type is String)
      • data_rate: Data within this group are stored at the variable segment rate. (Type is String)
    Dimensions: [ /gt1l/sea_ice_segments/delta_time = 0..276542 ]
    • latitude[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time longitude (Type is String)
        • description: Latitude, WGS84, North=+, Lat of segment center (Type is String)
        • long_name: Latitude (Type is String)
        • source: ATBD, section 4.4 (Type is String)
        • standard_name: latitude (Type is String)
        • units: degrees_north (Type is String)
        • valid_max: 90. (Type is Float64)
        • valid_min: -90. (Type is Float64)
    • delta_time[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float64)
      • attributes
        • contentType: physicalMeasurement (Type is String)
        • coordinates: latitude longitude (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)
        • long_name: Elapsed GPS seconds (Type is String)
        • source: telemetry (Type is String)
        • standard_name: time (Type is String)
        • units: seconds since 2018-01-01 (Type is String)
    • longitude[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude (Type is String)
        • description: Longitude, WGS84, East=+,Lon of segment center (Type is String)
        • long_name: Longitude (Type is String)
        • source: ATBD, section 4.4 (Type is String)
        • standard_name: longitude (Type is String)
        • units: degrees_east (Type is String)
        • valid_max: 180. (Type is Float64)
        • valid_min: -180. (Type is Float64)
    • height_segment_id[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Identifier of each height segment (Type is String)
        • long_name: Identifier of each height segment (Type is String)
        • source: ATBD, section 5.2 (Type is String)
        • units: 1 (Type is String)
    • geoseg_beg[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Geolocation segment (geoseg) ID associated with the first photon used in this sea ice segment (Type is String)
        • long_name: Beginning GEOSEG (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • seg_dist_x[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Along-track distance from the equator crossing to the segment center. (Type is String)
        • long_name: Along track distance (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • geoseg_end[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Geolocation segment (geoseg) ID associated with the last photon used in this sea ice segment (Type is String)
        • long_name: Ending GEOSEG (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • heights(Type is Group)
      • attributes
        • Description: Contains parameters relating to the calculated surface height for one Ground Track. As ICESat-2 orbits the earth, sequential transmit pulses illuminate six ground tracks on the surface of the earth. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • height_segment_fit_quality_flag[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Int8)
        • attributes
          • _FillValue: -1 (Type is Int8)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Flag describing the quality of the results of the along-track fit. (-1=height value is invalid; 1=ngrid_w < wlength/2; 2=ngrid_w >= wlength/2; 3=ngrid_dt < dtlength/2; 4=ngrid_dt >= dtlength/2; 5=ngrid_dt >= (dtlength-2): where 1 is best and 5 is poor). Heights are reported even if this flag indicates the height is invalid. (Type is String)
          • flag_meanings: invalid best high med low poor (Type is String)
          • flag_values: -1, 1, 2, 3, 4, 5 (Type is Int8)
          • long_name: height Quality Flag (Type is String)
          • source: ATBD, section 4.2.4.2 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 5 (Type is Int8)
          • valid_min: -1 (Type is Int8)
      • height_segment_length_seg[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: along-track length of segment containing n_photons_actual (Type is String)
          • long_name: length of segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_asr_calc[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Computed apparent surface reflectance for the sea ice segment. (Type is String)
          • long_name: Calculated Apparent Surface Reflectivity (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • height_segment_quality[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Height segment quality flag, 1 is good quality, 0 is bad depending on fit, wguassian, or layer flag (Type is String)
          • flag_meanings: bad_quality good_quality (Type is String)
          • flag_values: 0, 1 (Type is Int8)
          • long_name: Height Segment Quality Flag (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_n_pulse_seg[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Int32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: number of laser pulses (Type is String)
          • long_name: number of laser pulses (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • across_track_distance[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Across track distance of photons averaged over the sea ice height segment. (Type is String)
          • long_name: Across Track Distance (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_htcorr_skew[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height corection for skew (Type is String)
          • long_name: Height Correction for Skew (Type is String)
          • source: ATBD, section 4.2.6 (Type is String)
          • units: meters (Type is String)
      • height_segment_ssh_flag[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Identifies the height segments that are candidates for use as sea surface reference in freeboard calculations in ATL10. 0 = sea ice; 1 = sea surface (Type is String)
          • flag_meanings: sea_ice sea_surface (Type is String)
          • flag_values: 0, 1 (Type is Int8)
          • long_name: Sea Surface Flag (Type is String)
          • source: ATBD, section 4.3 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_height[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean height from along-track segment fit detremined by the sea ice algorithm (Type is String)
          • long_name: height of segment surface (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
      • height_segment_type[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Value that indicates segment surface type as sea ice or different types of sea surface. 0=cloud covered: rsurf (Type is String)
          • flag_meanings: cloud_covered other specular_lead_low_w_bkg specular_lead_low specular_lead_high_w_bkg specular_lead_high dark_lead_smooth_w_bkg dark_lead_smooth dark_lead_rough_w_bkg dark_lead_rough (Type is String)
          • flag_values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 (Type is Int8)
          • long_name: Segment surface type (Type is String)
          • source: ATBD, section 4.3 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 9 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_confidence[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Confidence level in the surface height estimate based on the number of photons; the background noise rate; and the error analysis (Type is String)
          • long_name: Surface height confidence (Type is String)
          • source: ATBD, section 4.2.4.2 (Type is String)
          • units: 1 (Type is String)
      • height_segment_surface_error_est[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Error estimate of the surface height (Type is String)
          • long_name: h surface error est (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_w_gaussian[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: width of best fit gaussian (Type is String)
          • long_name: width of best fit gaussian (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_rms[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: RMS difference between sea ice modeled and observed photon height distribution (Type is String)
          • long_name: height rms (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
    • geophysical(Type is Group)
      • attributes
        • Description: Contains geophysical parameters and corrections used to correct photon heights for geophysical effects, such as tides. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • height_segment_t2m[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Temperature at 2m above the displacement height (K) (Type is String)
          • long_name: temperature_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: temperature (Type is String)
          • units: K (Type is String)
      • height_segment_dac[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect. (Type is String)
          • long_name: Dynamic Atmosphere Correction (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_ps[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Sea Level Pressure (Pa) (Type is String)
          • long_name: sea level pressure (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: pressure (Type is String)
          • units: Pa (Type is String)
      • height_segment_ib[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Inverted barometer effect calculated from surface pressure (Type is String)
          • long_name: Inverted barometer effect (Type is String)
          • source: ATBD, section 4.2 (Type is String)
          • units: meters (Type is String)
      • height_segment_load[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Load Tide - Local displacement due to Ocean Loading (-6 to 0 cm). (Type is String)
          • long_name: Load Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_geoid[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Geoid height above WGS-84 reference ellipsoid (range -107 to 86m), based on the EGM2008 model. (Type is String)
          • long_name: EGM2008 Geoid (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_ocean[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Ocean Tides including diurnal and semi-diurnal (harmonic analysis), and longer period tides (dynamic and self-consistent equilibrium) (Type is String)
          • long_name: Ocean Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_v2m[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Northward wind at 2m above the displacement height (m/s-1) (Type is String)
          • long_name: Northward_wind_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: northward_wind (Type is String)
          • units: m s-1 (Type is String)
      • height_segment_mss[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean sea surface height above WGS-84 reference ellipsoid (range: -105 to 87m), based on the DTU13 model. (Type is String)
          • long_name: DTU13 Mean Sea Surface (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_u2m[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Eastward wind at 2m above the displacement height (m/s-1) (Type is String)
          • long_name: Eastward_wind_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: eastward_wind (Type is String)
          • units: m s-1 (Type is String)
      • height_segment_lpe[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Long period equilibrium tide self-consistent with ocean tide model (+-0.04m). (dependent only on time and latitude) (Type is String)
          • long_name: Equilibrium Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_earth[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Solid Earth Tide (Type is String)
          • long_name: Earth Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_pole[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Pole Tide -Rotational deformation due to polar motion (-1.5 to 1.5 cm). (Type is String)
          • long_name: Pole Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
    • stats(Type is Group)
      • attributes
        • Description: Contains parameters related to quality and corrections on the sea ice height paramters (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      Dimensions: [ /gt1l/sea_ice_segments/stats/ds_si_hist_bins = 0..220 ]
      • ds_si_hist_bins[ /gt1l/sea_ice_segments/stats/ds_si_hist_bins= 0..220] (Type is Int32)
        • attributes
          • contentType: auxiliaryInformation (Type is String)
          • description: Dimension scale indexing the sea ice histogram bins. The bin heights must be computed from information contained within the same group as the histogram. (Type is String)
          • long_name: Sea Ice Histogram Bins Dimension Scale (Type is String)
          • source: SeaIce ATBD (Type is String)
          • units: 1 (Type is String)
      • hist_median_h[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Median of the n_fit_photons heights (Type is String)
          • long_name: trimmed photon heights median (Type is String)
          • source: ATBD, section 4.2.3.1 (Type is String)
          • units: meters (Type is String)
      • height_filter_min[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height minimum used in the ssh height filter (Type is String)
          • long_name: Height Filter Min (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • cloud_flag_atm[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Int8)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of layers found from the backscatter profile using the DDA layer finder. (Type is String)
          • long_name: Cloud Flag Atm (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 10 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • fpb_avg_dt[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction average dead time (Type is String)
          • long_name: fpb correction average deadtime (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: ns (Type is String)
      • msw_flag[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Int8)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • 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)
          • long_name: Multiple Scattering Warning Flag (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 5 (Type is Int8)
          • valid_min: -1 (Type is Int8)
      • fpb_strength[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction strength (Type is String)
          • long_name: fpb correction strength (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: photons/shot (Type is String)
      • bsnow_con[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Int8)
        • attributes
          • _FillValue: 127 (Type is Int8)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Blowing snow confidence (Type is String)
          • long_name: Blowing snow confidence (Type is String)
          • source: ATL09 (Type is String)
          • units: 1 (Type is String)
      • layer_flag[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Int16)
        • attributes
          • contentType: qualityInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • flag_meanings: likely_clear likely_cloudy (Type is String)
          • flag_values: 0, 1 (Type is Int16)
          • long_name: Consolidated cloud flag (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int16)
          • valid_min: 0 (Type is Int16)
      • hist_photon_bin_size[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: bin size of photon height histogram (Type is String)
          • long_name: height histogram bin size (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • backgr_calc[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Calculated background count rate based on sun angle, surface slope, unit reflectance (Type is String)
          • long_name: background count rate calculated (Type is String)
          • source: ATBD, section 4.2.3 (Type is String)
          • units: hz (Type is String)
      • fpb_corr[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated first-photon bias(fpb) correction to mean segment height (Type is String)
          • long_name: first photon bias correction (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • bsnow_h[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Blowing snow layer top height (Type is String)
          • long_name: Blowing snow top h (Type is String)
          • source: ATL09 (Type is String)
          • units: meters (Type is String)
      • hist_photon_bottom[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: lower bound of height histogram (Type is String)
          • long_name: height histogram minimum (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • background_r_norm[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background rate normalized to a fixed solar elevation angle (Type is String)
          • long_name: Normalized background (50-shot) (Type is String)
          • source: ATBD section 4.3.1.3 (Type is String)
          • units: hz (Type is String)
      • exmax_mean_2[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mean 2 (Type is String)
          • long_name: Exmax Mean 2 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • background_int_height[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: The height of the altimetric range window after subtracting the height span of the signal photon events in the 50-shot span (Type is String)
          • long_name: Height of column used in background calculation (Type is String)
          • source: ATBD, section 7.3 (Type is String)
          • units: meters (Type is String)
      • n_photons_actual[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons gathered (Type is String)
          • long_name: Number of photons found for the segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • ice_conc[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: sea ice concentration (Type is String)
          • long_name: sea ice concentration (Type is String)
          • source: ATBD, section 3.1.4 (Type is String)
          • units: 1 (Type is String)
      • exmax_stdev_2[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height standard deviation 2 (Type is String)
          • long_name: Exmax Stdev 2 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • cloud_flag_asr[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Int16)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Cloud flag (probability) from apparent surface reflectance. 0=clear with high confidence; 1=clear with medium confidence; 2=clear with low confidence; 3=cloudy with low confidence; 4=cloudy with medium confidence; 5=cloudy with high confidence; 6=unknown (Type is String)
          • flag_meanings: clear_with_high_confidence clear_with_medium_confidence clear_with_low_confidence cloudy_with_low_confidence cloudy_with_medium_confidence cloudy_with_high_confidence unknown (Type is String)
          • flag_values: 0, 1, 2, 3, 4, 5, 6 (Type is Int16)
          • long_name: Cloud Flag ASR (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 6 (Type is Int16)
          • valid_min: 0 (Type is Int16)
      • exmax_stdev_1[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height standard deviation 1 (Type is String)
          • long_name: Exmax Stdev 1 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • fpb_corr_width[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction width (Type is String)
          • long_name: fpb correction width (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: ns (Type is String)
      • height_coarse_stdev[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height standard deviation of coarse tracker (Type is String)
          • long_name: Coarse Height Sdev (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • height_filter_05[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height fifth percentile used in the ssh height filter (Type is String)
          • long_name: Height Filter 5th Percentile (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • n_photons_used[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons in the trimmed histogram. (Type is String)
          • long_name: Number of photons used for fit (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • backgr_r_200[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background count rate, averaged over the segment based on ATLAS 50 pulse counts (Type is String)
          • long_name: Background rate 200 hz (Type is String)
          • source: ATL09 (Type is String)
          • units: hz (Type is String)
      • hist_photon_top[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: upper bound of height histogram (Type is String)
          • long_name: height histogram maximum (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • hist_w[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Segment histogram width estimate (Type is String)
          • long_name: Segment histogram width estimate (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • hist_mean_h[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean of the n_fit_photons heights (Type is String)
          • long_name: photon heights mean (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_coarse_mn[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height mean of coarse tracker (Type is String)
          • long_name: Coarse Track Height Mean (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • exmax_mean_1[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mean 1 (Type is String)
          • long_name: Exmax Mean 1 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • hist_photon_heights[ /gt1l/sea_ice_segments/delta_time= 0..276542] [ /gt1l/sea_ice_segments/stats/ds_si_hist_bins= 0..220] (Type is Int16)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Histogram of the n_fit_photons heights (Type is String)
          • long_name: photon heights histogram (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • trim_height_top[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: maximum height of trimmed photons used in the surface calculation procedure (Type is String)
          • long_name: maximum height of trimmed photons (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • exmax_mix[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mix ratio (Type is String)
          • long_name: Exmax Mix (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • asr_25[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Apparent surface reflectance at 25 hz, averaged to the sea ice segment. (Type is String)
          • long_name: Apparent Surface Reflectance 25hz (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • photon_rate[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: photon count rate, averaged over segment (Type is String)
          • long_name: photon rate (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: photons/shot (Type is String)
      • trim_height_bottom[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: minimum height of trimmed photons used in the surface calculation procedure (Type is String)
          • long_name: minimum height of trimmed photons (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • n_photons_define[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons to gather. (Type is String)
          • long_name: Number of photons defining the segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • backgr_r_25[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background count rate, averaged over the segment based on 25 hz atmosphere (Type is String)
          • long_name: Background rate 25hz (Type is String)
          • source: ATL09 (Type is String)
          • units: hz (Type is String)
    • geolocation(Type is Group)
      • attributes
        • Description: Contains parameters related to geolocation. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • rgt[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Int16)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: Reference Ground track (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1387 (Type is Int16)
          • valid_min: 1 (Type is Int16)
      • sigma_lon[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point east longitude: 1- sigma (degrees). Applies to all other photons in the group. (Type is String)
          • long_name: longitude uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (Type is String)
      • ref_atm_delay[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Atmospheric path delay, in range, for the reference photon. (Type is String)
          • long_name: Reference Photon Atm. Path Delay (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • beam_azimuth[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: The direction, eastwards from north, of the laser beam vector as seen by an observer at the laser ground spot viewing toward the spacecraft (i.e., the vector from the ground to the spacecraft). When the spacecraft is precisely at the geodetic zenith, the value will be 99999 degrees. (Type is String)
          • long_name: beam azimuth (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees_east (Type is String)
      • solar_azimuth[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • contentType: physicalMeansurement (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: solar azimuth (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees_east (Type is String)
      • ref_atm_delay_derivative[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Atmospheric path delay derivative with respect to ellipsoid for the reference photon, in meters per meter. (Type is String)
          • long_name: Derivative of Atm. Path Delay (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters/meter (Type is String)
      • sigma_lat[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point geodetic latitude: 1- sigma (degrees). Applies to all other photons in the group (Type is String)
          • long_name: latitude uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • beam_coelev[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: beam co-elevation (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (Type is String)
      • sigma_h[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m). Error estimates for all other photons in the group are computed with the scale defined below. (Type is String)
          • long_name: height uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • solar_elevation[ /gt1l/sea_ice_segments/delta_time= 0..276542] (Type is Float32)
        • attributes
          • contentType: physicalMeansurement (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: solar elevation (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (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
      • contentType: qualityInformation (Type is String)
      • description: Flag indicating granule failure reason. 0=no failure; 1=processing error; 2=Insufficient output data was generated; 3=TBD Failure; 4=TBD_Failure; 5=other failure. (Type is String)
      • flag_meanings: no_failure PROCESS_ERROR INSUFFICIENT_OUTPUT failure_3 failure_4 OTHER_FAILURE (Type is String)
      • flag_values: 0, 1, 2, 3, 4, 5 (Type is Int32)
      • long_name: Granule Failure Reason (Type is String)
      • source: Operations (Type is String)
      • units: 1 (Type is String)
      • valid_max: 5 (Type is Int32)
      • valid_min: 0 (Type is Int32)
  • qa_granule_pass_fail[ 0..0] (Type is Int32)
    • attributes
      • contentType: qualityInformation (Type is String)
      • description: Flag indicating granule quality. 0=granule passes automatic QA. 1=granule fails automatic QA. (Type is String)
      • flag_meanings: PASS FAIL (Type is String)
      • flag_values: 0, 1 (Type is Int32)
      • long_name: Granule Pass Flag (Type is String)
      • source: Operations (Type is String)
      • units: 1 (Type is String)
      • valid_max: 1 (Type is Int32)
      • valid_min: 0 (Type is Int32)
gt3l(Type is Group)
  • attributes
    • Description: This ground contains parameters and subgroups related a specific groundtrack. (Type is String)
    • data_rate: Each subgroup identifies its particular data rate. (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)
  • sea_ice_segments(Type is Group)
    • attributes
      • Description: Top group for sea ice segments as computed by the ATBD aglorithm (Type is String)
      • data_rate: Data within this group are stored at the variable segment rate. (Type is String)
    Dimensions: [ /gt3l/sea_ice_segments/delta_time = 0..274700 ]
    • latitude[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time longitude (Type is String)
        • description: Latitude, WGS84, North=+, Lat of segment center (Type is String)
        • long_name: Latitude (Type is String)
        • source: ATBD, section 4.4 (Type is String)
        • standard_name: latitude (Type is String)
        • units: degrees_north (Type is String)
        • valid_max: 90. (Type is Float64)
        • valid_min: -90. (Type is Float64)
    • delta_time[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float64)
      • attributes
        • contentType: physicalMeasurement (Type is String)
        • coordinates: latitude longitude (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)
        • long_name: Elapsed GPS seconds (Type is String)
        • source: telemetry (Type is String)
        • standard_name: time (Type is String)
        • units: seconds since 2018-01-01 (Type is String)
    • longitude[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude (Type is String)
        • description: Longitude, WGS84, East=+,Lon of segment center (Type is String)
        • long_name: Longitude (Type is String)
        • source: ATBD, section 4.4 (Type is String)
        • standard_name: longitude (Type is String)
        • units: degrees_east (Type is String)
        • valid_max: 180. (Type is Float64)
        • valid_min: -180. (Type is Float64)
    • height_segment_id[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Identifier of each height segment (Type is String)
        • long_name: Identifier of each height segment (Type is String)
        • source: ATBD, section 5.2 (Type is String)
        • units: 1 (Type is String)
    • geoseg_beg[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Geolocation segment (geoseg) ID associated with the first photon used in this sea ice segment (Type is String)
        • long_name: Beginning GEOSEG (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • seg_dist_x[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Along-track distance from the equator crossing to the segment center. (Type is String)
        • long_name: Along track distance (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • geoseg_end[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Geolocation segment (geoseg) ID associated with the last photon used in this sea ice segment (Type is String)
        • long_name: Ending GEOSEG (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • heights(Type is Group)
      • attributes
        • Description: Contains parameters relating to the calculated surface height for one Ground Track. As ICESat-2 orbits the earth, sequential transmit pulses illuminate six ground tracks on the surface of the earth. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • height_segment_fit_quality_flag[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Int8)
        • attributes
          • _FillValue: -1 (Type is Int8)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Flag describing the quality of the results of the along-track fit. (-1=height value is invalid; 1=ngrid_w < wlength/2; 2=ngrid_w >= wlength/2; 3=ngrid_dt < dtlength/2; 4=ngrid_dt >= dtlength/2; 5=ngrid_dt >= (dtlength-2): where 1 is best and 5 is poor). Heights are reported even if this flag indicates the height is invalid. (Type is String)
          • flag_meanings: invalid best high med low poor (Type is String)
          • flag_values: -1, 1, 2, 3, 4, 5 (Type is Int8)
          • long_name: height Quality Flag (Type is String)
          • source: ATBD, section 4.2.4.2 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 5 (Type is Int8)
          • valid_min: -1 (Type is Int8)
      • height_segment_length_seg[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: along-track length of segment containing n_photons_actual (Type is String)
          • long_name: length of segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_asr_calc[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Computed apparent surface reflectance for the sea ice segment. (Type is String)
          • long_name: Calculated Apparent Surface Reflectivity (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • height_segment_quality[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Height segment quality flag, 1 is good quality, 0 is bad depending on fit, wguassian, or layer flag (Type is String)
          • flag_meanings: bad_quality good_quality (Type is String)
          • flag_values: 0, 1 (Type is Int8)
          • long_name: Height Segment Quality Flag (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_n_pulse_seg[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Int32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: number of laser pulses (Type is String)
          • long_name: number of laser pulses (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • across_track_distance[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Across track distance of photons averaged over the sea ice height segment. (Type is String)
          • long_name: Across Track Distance (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_htcorr_skew[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height corection for skew (Type is String)
          • long_name: Height Correction for Skew (Type is String)
          • source: ATBD, section 4.2.6 (Type is String)
          • units: meters (Type is String)
      • height_segment_ssh_flag[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Identifies the height segments that are candidates for use as sea surface reference in freeboard calculations in ATL10. 0 = sea ice; 1 = sea surface (Type is String)
          • flag_meanings: sea_ice sea_surface (Type is String)
          • flag_values: 0, 1 (Type is Int8)
          • long_name: Sea Surface Flag (Type is String)
          • source: ATBD, section 4.3 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_height[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean height from along-track segment fit detremined by the sea ice algorithm (Type is String)
          • long_name: height of segment surface (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
      • height_segment_type[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Value that indicates segment surface type as sea ice or different types of sea surface. 0=cloud covered: rsurf (Type is String)
          • flag_meanings: cloud_covered other specular_lead_low_w_bkg specular_lead_low specular_lead_high_w_bkg specular_lead_high dark_lead_smooth_w_bkg dark_lead_smooth dark_lead_rough_w_bkg dark_lead_rough (Type is String)
          • flag_values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 (Type is Int8)
          • long_name: Segment surface type (Type is String)
          • source: ATBD, section 4.3 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 9 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_confidence[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Confidence level in the surface height estimate based on the number of photons; the background noise rate; and the error analysis (Type is String)
          • long_name: Surface height confidence (Type is String)
          • source: ATBD, section 4.2.4.2 (Type is String)
          • units: 1 (Type is String)
      • height_segment_surface_error_est[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Error estimate of the surface height (Type is String)
          • long_name: h surface error est (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_w_gaussian[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: width of best fit gaussian (Type is String)
          • long_name: width of best fit gaussian (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_rms[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: RMS difference between sea ice modeled and observed photon height distribution (Type is String)
          • long_name: height rms (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
    • geophysical(Type is Group)
      • attributes
        • Description: Contains geophysical parameters and corrections used to correct photon heights for geophysical effects, such as tides. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • height_segment_t2m[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Temperature at 2m above the displacement height (K) (Type is String)
          • long_name: temperature_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: temperature (Type is String)
          • units: K (Type is String)
      • height_segment_dac[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect. (Type is String)
          • long_name: Dynamic Atmosphere Correction (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_ps[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Sea Level Pressure (Pa) (Type is String)
          • long_name: sea level pressure (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: pressure (Type is String)
          • units: Pa (Type is String)
      • height_segment_ib[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Inverted barometer effect calculated from surface pressure (Type is String)
          • long_name: Inverted barometer effect (Type is String)
          • source: ATBD, section 4.2 (Type is String)
          • units: meters (Type is String)
      • height_segment_load[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Load Tide - Local displacement due to Ocean Loading (-6 to 0 cm). (Type is String)
          • long_name: Load Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_geoid[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Geoid height above WGS-84 reference ellipsoid (range -107 to 86m), based on the EGM2008 model. (Type is String)
          • long_name: EGM2008 Geoid (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_ocean[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Ocean Tides including diurnal and semi-diurnal (harmonic analysis), and longer period tides (dynamic and self-consistent equilibrium) (Type is String)
          • long_name: Ocean Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_v2m[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Northward wind at 2m above the displacement height (m/s-1) (Type is String)
          • long_name: Northward_wind_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: northward_wind (Type is String)
          • units: m s-1 (Type is String)
      • height_segment_mss[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean sea surface height above WGS-84 reference ellipsoid (range: -105 to 87m), based on the DTU13 model. (Type is String)
          • long_name: DTU13 Mean Sea Surface (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_u2m[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Eastward wind at 2m above the displacement height (m/s-1) (Type is String)
          • long_name: Eastward_wind_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: eastward_wind (Type is String)
          • units: m s-1 (Type is String)
      • height_segment_lpe[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Long period equilibrium tide self-consistent with ocean tide model (+-0.04m). (dependent only on time and latitude) (Type is String)
          • long_name: Equilibrium Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_earth[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Solid Earth Tide (Type is String)
          • long_name: Earth Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_pole[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Pole Tide -Rotational deformation due to polar motion (-1.5 to 1.5 cm). (Type is String)
          • long_name: Pole Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
    • stats(Type is Group)
      • attributes
        • Description: Contains parameters related to quality and corrections on the sea ice height paramters (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      Dimensions: [ /gt3l/sea_ice_segments/stats/ds_si_hist_bins = 0..220 ]
      • ds_si_hist_bins[ /gt3l/sea_ice_segments/stats/ds_si_hist_bins= 0..220] (Type is Int32)
        • attributes
          • contentType: auxiliaryInformation (Type is String)
          • description: Dimension scale indexing the sea ice histogram bins. The bin heights must be computed from information contained within the same group as the histogram. (Type is String)
          • long_name: Sea Ice Histogram Bins Dimension Scale (Type is String)
          • source: SeaIce ATBD (Type is String)
          • units: 1 (Type is String)
      • hist_median_h[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Median of the n_fit_photons heights (Type is String)
          • long_name: trimmed photon heights median (Type is String)
          • source: ATBD, section 4.2.3.1 (Type is String)
          • units: meters (Type is String)
      • height_filter_min[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height minimum used in the ssh height filter (Type is String)
          • long_name: Height Filter Min (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • cloud_flag_atm[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Int8)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of layers found from the backscatter profile using the DDA layer finder. (Type is String)
          • long_name: Cloud Flag Atm (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 10 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • fpb_avg_dt[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction average dead time (Type is String)
          • long_name: fpb correction average deadtime (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: ns (Type is String)
      • msw_flag[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Int8)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • 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)
          • long_name: Multiple Scattering Warning Flag (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 5 (Type is Int8)
          • valid_min: -1 (Type is Int8)
      • fpb_strength[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction strength (Type is String)
          • long_name: fpb correction strength (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: photons/shot (Type is String)
      • bsnow_con[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Int8)
        • attributes
          • _FillValue: 127 (Type is Int8)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Blowing snow confidence (Type is String)
          • long_name: Blowing snow confidence (Type is String)
          • source: ATL09 (Type is String)
          • units: 1 (Type is String)
      • layer_flag[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Int16)
        • attributes
          • contentType: qualityInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • flag_meanings: likely_clear likely_cloudy (Type is String)
          • flag_values: 0, 1 (Type is Int16)
          • long_name: Consolidated cloud flag (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int16)
          • valid_min: 0 (Type is Int16)
      • hist_photon_bin_size[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: bin size of photon height histogram (Type is String)
          • long_name: height histogram bin size (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • backgr_calc[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Calculated background count rate based on sun angle, surface slope, unit reflectance (Type is String)
          • long_name: background count rate calculated (Type is String)
          • source: ATBD, section 4.2.3 (Type is String)
          • units: hz (Type is String)
      • fpb_corr[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated first-photon bias(fpb) correction to mean segment height (Type is String)
          • long_name: first photon bias correction (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • bsnow_h[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Blowing snow layer top height (Type is String)
          • long_name: Blowing snow top h (Type is String)
          • source: ATL09 (Type is String)
          • units: meters (Type is String)
      • hist_photon_bottom[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: lower bound of height histogram (Type is String)
          • long_name: height histogram minimum (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • background_r_norm[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background rate normalized to a fixed solar elevation angle (Type is String)
          • long_name: Normalized background (50-shot) (Type is String)
          • source: ATBD section 4.3.1.3 (Type is String)
          • units: hz (Type is String)
      • exmax_mean_2[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mean 2 (Type is String)
          • long_name: Exmax Mean 2 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • background_int_height[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: The height of the altimetric range window after subtracting the height span of the signal photon events in the 50-shot span (Type is String)
          • long_name: Height of column used in background calculation (Type is String)
          • source: ATBD, section 7.3 (Type is String)
          • units: meters (Type is String)
      • n_photons_actual[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons gathered (Type is String)
          • long_name: Number of photons found for the segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • ice_conc[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: sea ice concentration (Type is String)
          • long_name: sea ice concentration (Type is String)
          • source: ATBD, section 3.1.4 (Type is String)
          • units: 1 (Type is String)
      • exmax_stdev_2[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height standard deviation 2 (Type is String)
          • long_name: Exmax Stdev 2 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • cloud_flag_asr[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Int16)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Cloud flag (probability) from apparent surface reflectance. 0=clear with high confidence; 1=clear with medium confidence; 2=clear with low confidence; 3=cloudy with low confidence; 4=cloudy with medium confidence; 5=cloudy with high confidence; 6=unknown (Type is String)
          • flag_meanings: clear_with_high_confidence clear_with_medium_confidence clear_with_low_confidence cloudy_with_low_confidence cloudy_with_medium_confidence cloudy_with_high_confidence unknown (Type is String)
          • flag_values: 0, 1, 2, 3, 4, 5, 6 (Type is Int16)
          • long_name: Cloud Flag ASR (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 6 (Type is Int16)
          • valid_min: 0 (Type is Int16)
      • exmax_stdev_1[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height standard deviation 1 (Type is String)
          • long_name: Exmax Stdev 1 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • fpb_corr_width[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction width (Type is String)
          • long_name: fpb correction width (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: ns (Type is String)
      • height_coarse_stdev[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height standard deviation of coarse tracker (Type is String)
          • long_name: Coarse Height Sdev (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • height_filter_05[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height fifth percentile used in the ssh height filter (Type is String)
          • long_name: Height Filter 5th Percentile (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • n_photons_used[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons in the trimmed histogram. (Type is String)
          • long_name: Number of photons used for fit (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • backgr_r_200[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background count rate, averaged over the segment based on ATLAS 50 pulse counts (Type is String)
          • long_name: Background rate 200 hz (Type is String)
          • source: ATL09 (Type is String)
          • units: hz (Type is String)
      • hist_photon_top[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: upper bound of height histogram (Type is String)
          • long_name: height histogram maximum (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • hist_w[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Segment histogram width estimate (Type is String)
          • long_name: Segment histogram width estimate (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • hist_mean_h[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean of the n_fit_photons heights (Type is String)
          • long_name: photon heights mean (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_coarse_mn[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height mean of coarse tracker (Type is String)
          • long_name: Coarse Track Height Mean (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • exmax_mean_1[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mean 1 (Type is String)
          • long_name: Exmax Mean 1 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • hist_photon_heights[ /gt3l/sea_ice_segments/delta_time= 0..274700] [ /gt3l/sea_ice_segments/stats/ds_si_hist_bins= 0..220] (Type is Int16)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Histogram of the n_fit_photons heights (Type is String)
          • long_name: photon heights histogram (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • trim_height_top[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: maximum height of trimmed photons used in the surface calculation procedure (Type is String)
          • long_name: maximum height of trimmed photons (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • exmax_mix[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mix ratio (Type is String)
          • long_name: Exmax Mix (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • asr_25[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Apparent surface reflectance at 25 hz, averaged to the sea ice segment. (Type is String)
          • long_name: Apparent Surface Reflectance 25hz (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • photon_rate[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: photon count rate, averaged over segment (Type is String)
          • long_name: photon rate (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: photons/shot (Type is String)
      • trim_height_bottom[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: minimum height of trimmed photons used in the surface calculation procedure (Type is String)
          • long_name: minimum height of trimmed photons (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • n_photons_define[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons to gather. (Type is String)
          • long_name: Number of photons defining the segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • backgr_r_25[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background count rate, averaged over the segment based on 25 hz atmosphere (Type is String)
          • long_name: Background rate 25hz (Type is String)
          • source: ATL09 (Type is String)
          • units: hz (Type is String)
    • geolocation(Type is Group)
      • attributes
        • Description: Contains parameters related to geolocation. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • rgt[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Int16)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: Reference Ground track (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1387 (Type is Int16)
          • valid_min: 1 (Type is Int16)
      • sigma_lon[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point east longitude: 1- sigma (degrees). Applies to all other photons in the group. (Type is String)
          • long_name: longitude uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (Type is String)
      • ref_atm_delay[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Atmospheric path delay, in range, for the reference photon. (Type is String)
          • long_name: Reference Photon Atm. Path Delay (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • beam_azimuth[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: The direction, eastwards from north, of the laser beam vector as seen by an observer at the laser ground spot viewing toward the spacecraft (i.e., the vector from the ground to the spacecraft). When the spacecraft is precisely at the geodetic zenith, the value will be 99999 degrees. (Type is String)
          • long_name: beam azimuth (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees_east (Type is String)
      • solar_azimuth[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • contentType: physicalMeansurement (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: solar azimuth (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees_east (Type is String)
      • ref_atm_delay_derivative[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Atmospheric path delay derivative with respect to ellipsoid for the reference photon, in meters per meter. (Type is String)
          • long_name: Derivative of Atm. Path Delay (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters/meter (Type is String)
      • sigma_lat[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point geodetic latitude: 1- sigma (degrees). Applies to all other photons in the group (Type is String)
          • long_name: latitude uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • beam_coelev[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: beam co-elevation (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (Type is String)
      • sigma_h[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m). Error estimates for all other photons in the group are computed with the scale defined below. (Type is String)
          • long_name: height uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • solar_elevation[ /gt3l/sea_ice_segments/delta_time= 0..274700] (Type is Float32)
        • attributes
          • contentType: physicalMeansurement (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: solar elevation (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (Type is String)
gt2l(Type is Group)
  • attributes
    • Description: This ground contains parameters and subgroups related a specific groundtrack. (Type is String)
    • data_rate: Each subgroup identifies its particular data rate. (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)
  • sea_ice_segments(Type is Group)
    • attributes
      • Description: Top group for sea ice segments as computed by the ATBD aglorithm (Type is String)
      • data_rate: Data within this group are stored at the variable segment rate. (Type is String)
    Dimensions: [ /gt2l/sea_ice_segments/delta_time = 0..221424 ]
    • latitude[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time longitude (Type is String)
        • description: Latitude, WGS84, North=+, Lat of segment center (Type is String)
        • long_name: Latitude (Type is String)
        • source: ATBD, section 4.4 (Type is String)
        • standard_name: latitude (Type is String)
        • units: degrees_north (Type is String)
        • valid_max: 90. (Type is Float64)
        • valid_min: -90. (Type is Float64)
    • delta_time[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float64)
      • attributes
        • contentType: physicalMeasurement (Type is String)
        • coordinates: latitude longitude (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)
        • long_name: Elapsed GPS seconds (Type is String)
        • source: telemetry (Type is String)
        • standard_name: time (Type is String)
        • units: seconds since 2018-01-01 (Type is String)
    • longitude[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude (Type is String)
        • description: Longitude, WGS84, East=+,Lon of segment center (Type is String)
        • long_name: Longitude (Type is String)
        • source: ATBD, section 4.4 (Type is String)
        • standard_name: longitude (Type is String)
        • units: degrees_east (Type is String)
        • valid_max: 180. (Type is Float64)
        • valid_min: -180. (Type is Float64)
    • height_segment_id[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Identifier of each height segment (Type is String)
        • long_name: Identifier of each height segment (Type is String)
        • source: ATBD, section 5.2 (Type is String)
        • units: 1 (Type is String)
    • geoseg_beg[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Geolocation segment (geoseg) ID associated with the first photon used in this sea ice segment (Type is String)
        • long_name: Beginning GEOSEG (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • seg_dist_x[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Along-track distance from the equator crossing to the segment center. (Type is String)
        • long_name: Along track distance (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • geoseg_end[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Geolocation segment (geoseg) ID associated with the last photon used in this sea ice segment (Type is String)
        • long_name: Ending GEOSEG (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • heights(Type is Group)
      • attributes
        • Description: Contains parameters relating to the calculated surface height for one Ground Track. As ICESat-2 orbits the earth, sequential transmit pulses illuminate six ground tracks on the surface of the earth. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • height_segment_fit_quality_flag[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Int8)
        • attributes
          • _FillValue: -1 (Type is Int8)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Flag describing the quality of the results of the along-track fit. (-1=height value is invalid; 1=ngrid_w < wlength/2; 2=ngrid_w >= wlength/2; 3=ngrid_dt < dtlength/2; 4=ngrid_dt >= dtlength/2; 5=ngrid_dt >= (dtlength-2): where 1 is best and 5 is poor). Heights are reported even if this flag indicates the height is invalid. (Type is String)
          • flag_meanings: invalid best high med low poor (Type is String)
          • flag_values: -1, 1, 2, 3, 4, 5 (Type is Int8)
          • long_name: height Quality Flag (Type is String)
          • source: ATBD, section 4.2.4.2 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 5 (Type is Int8)
          • valid_min: -1 (Type is Int8)
      • height_segment_length_seg[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: along-track length of segment containing n_photons_actual (Type is String)
          • long_name: length of segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_asr_calc[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Computed apparent surface reflectance for the sea ice segment. (Type is String)
          • long_name: Calculated Apparent Surface Reflectivity (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • height_segment_quality[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Height segment quality flag, 1 is good quality, 0 is bad depending on fit, wguassian, or layer flag (Type is String)
          • flag_meanings: bad_quality good_quality (Type is String)
          • flag_values: 0, 1 (Type is Int8)
          • long_name: Height Segment Quality Flag (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_n_pulse_seg[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Int32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: number of laser pulses (Type is String)
          • long_name: number of laser pulses (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • across_track_distance[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Across track distance of photons averaged over the sea ice height segment. (Type is String)
          • long_name: Across Track Distance (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_htcorr_skew[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height corection for skew (Type is String)
          • long_name: Height Correction for Skew (Type is String)
          • source: ATBD, section 4.2.6 (Type is String)
          • units: meters (Type is String)
      • height_segment_ssh_flag[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Identifies the height segments that are candidates for use as sea surface reference in freeboard calculations in ATL10. 0 = sea ice; 1 = sea surface (Type is String)
          • flag_meanings: sea_ice sea_surface (Type is String)
          • flag_values: 0, 1 (Type is Int8)
          • long_name: Sea Surface Flag (Type is String)
          • source: ATBD, section 4.3 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_height[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean height from along-track segment fit detremined by the sea ice algorithm (Type is String)
          • long_name: height of segment surface (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
      • height_segment_type[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Value that indicates segment surface type as sea ice or different types of sea surface. 0=cloud covered: rsurf (Type is String)
          • flag_meanings: cloud_covered other specular_lead_low_w_bkg specular_lead_low specular_lead_high_w_bkg specular_lead_high dark_lead_smooth_w_bkg dark_lead_smooth dark_lead_rough_w_bkg dark_lead_rough (Type is String)
          • flag_values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 (Type is Int8)
          • long_name: Segment surface type (Type is String)
          • source: ATBD, section 4.3 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 9 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_confidence[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Confidence level in the surface height estimate based on the number of photons; the background noise rate; and the error analysis (Type is String)
          • long_name: Surface height confidence (Type is String)
          • source: ATBD, section 4.2.4.2 (Type is String)
          • units: 1 (Type is String)
      • height_segment_surface_error_est[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Error estimate of the surface height (Type is String)
          • long_name: h surface error est (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_w_gaussian[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: width of best fit gaussian (Type is String)
          • long_name: width of best fit gaussian (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_rms[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: RMS difference between sea ice modeled and observed photon height distribution (Type is String)
          • long_name: height rms (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
    • geophysical(Type is Group)
      • attributes
        • Description: Contains geophysical parameters and corrections used to correct photon heights for geophysical effects, such as tides. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • height_segment_t2m[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Temperature at 2m above the displacement height (K) (Type is String)
          • long_name: temperature_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: temperature (Type is String)
          • units: K (Type is String)
      • height_segment_dac[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect. (Type is String)
          • long_name: Dynamic Atmosphere Correction (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_ps[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Sea Level Pressure (Pa) (Type is String)
          • long_name: sea level pressure (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: pressure (Type is String)
          • units: Pa (Type is String)
      • height_segment_ib[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Inverted barometer effect calculated from surface pressure (Type is String)
          • long_name: Inverted barometer effect (Type is String)
          • source: ATBD, section 4.2 (Type is String)
          • units: meters (Type is String)
      • height_segment_load[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Load Tide - Local displacement due to Ocean Loading (-6 to 0 cm). (Type is String)
          • long_name: Load Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_geoid[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Geoid height above WGS-84 reference ellipsoid (range -107 to 86m), based on the EGM2008 model. (Type is String)
          • long_name: EGM2008 Geoid (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_ocean[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Ocean Tides including diurnal and semi-diurnal (harmonic analysis), and longer period tides (dynamic and self-consistent equilibrium) (Type is String)
          • long_name: Ocean Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_v2m[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Northward wind at 2m above the displacement height (m/s-1) (Type is String)
          • long_name: Northward_wind_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: northward_wind (Type is String)
          • units: m s-1 (Type is String)
      • height_segment_mss[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean sea surface height above WGS-84 reference ellipsoid (range: -105 to 87m), based on the DTU13 model. (Type is String)
          • long_name: DTU13 Mean Sea Surface (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_u2m[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Eastward wind at 2m above the displacement height (m/s-1) (Type is String)
          • long_name: Eastward_wind_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: eastward_wind (Type is String)
          • units: m s-1 (Type is String)
      • height_segment_lpe[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Long period equilibrium tide self-consistent with ocean tide model (+-0.04m). (dependent only on time and latitude) (Type is String)
          • long_name: Equilibrium Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_earth[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Solid Earth Tide (Type is String)
          • long_name: Earth Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_pole[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Pole Tide -Rotational deformation due to polar motion (-1.5 to 1.5 cm). (Type is String)
          • long_name: Pole Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
    • stats(Type is Group)
      • attributes
        • Description: Contains parameters related to quality and corrections on the sea ice height paramters (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      Dimensions: [ /gt2l/sea_ice_segments/stats/ds_si_hist_bins = 0..220 ]
      • ds_si_hist_bins[ /gt2l/sea_ice_segments/stats/ds_si_hist_bins= 0..220] (Type is Int32)
        • attributes
          • contentType: auxiliaryInformation (Type is String)
          • description: Dimension scale indexing the sea ice histogram bins. The bin heights must be computed from information contained within the same group as the histogram. (Type is String)
          • long_name: Sea Ice Histogram Bins Dimension Scale (Type is String)
          • source: SeaIce ATBD (Type is String)
          • units: 1 (Type is String)
      • hist_median_h[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Median of the n_fit_photons heights (Type is String)
          • long_name: trimmed photon heights median (Type is String)
          • source: ATBD, section 4.2.3.1 (Type is String)
          • units: meters (Type is String)
      • height_filter_min[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height minimum used in the ssh height filter (Type is String)
          • long_name: Height Filter Min (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • cloud_flag_atm[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Int8)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of layers found from the backscatter profile using the DDA layer finder. (Type is String)
          • long_name: Cloud Flag Atm (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 10 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • fpb_avg_dt[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction average dead time (Type is String)
          • long_name: fpb correction average deadtime (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: ns (Type is String)
      • msw_flag[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Int8)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • 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)
          • long_name: Multiple Scattering Warning Flag (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 5 (Type is Int8)
          • valid_min: -1 (Type is Int8)
      • fpb_strength[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction strength (Type is String)
          • long_name: fpb correction strength (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: photons/shot (Type is String)
      • bsnow_con[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Int8)
        • attributes
          • _FillValue: 127 (Type is Int8)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Blowing snow confidence (Type is String)
          • long_name: Blowing snow confidence (Type is String)
          • source: ATL09 (Type is String)
          • units: 1 (Type is String)
      • layer_flag[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Int16)
        • attributes
          • contentType: qualityInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • flag_meanings: likely_clear likely_cloudy (Type is String)
          • flag_values: 0, 1 (Type is Int16)
          • long_name: Consolidated cloud flag (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int16)
          • valid_min: 0 (Type is Int16)
      • hist_photon_bin_size[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: bin size of photon height histogram (Type is String)
          • long_name: height histogram bin size (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • backgr_calc[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Calculated background count rate based on sun angle, surface slope, unit reflectance (Type is String)
          • long_name: background count rate calculated (Type is String)
          • source: ATBD, section 4.2.3 (Type is String)
          • units: hz (Type is String)
      • fpb_corr[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated first-photon bias(fpb) correction to mean segment height (Type is String)
          • long_name: first photon bias correction (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • bsnow_h[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Blowing snow layer top height (Type is String)
          • long_name: Blowing snow top h (Type is String)
          • source: ATL09 (Type is String)
          • units: meters (Type is String)
      • hist_photon_bottom[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: lower bound of height histogram (Type is String)
          • long_name: height histogram minimum (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • background_r_norm[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background rate normalized to a fixed solar elevation angle (Type is String)
          • long_name: Normalized background (50-shot) (Type is String)
          • source: ATBD section 4.3.1.3 (Type is String)
          • units: hz (Type is String)
      • exmax_mean_2[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mean 2 (Type is String)
          • long_name: Exmax Mean 2 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • background_int_height[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: The height of the altimetric range window after subtracting the height span of the signal photon events in the 50-shot span (Type is String)
          • long_name: Height of column used in background calculation (Type is String)
          • source: ATBD, section 7.3 (Type is String)
          • units: meters (Type is String)
      • n_photons_actual[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons gathered (Type is String)
          • long_name: Number of photons found for the segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • ice_conc[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: sea ice concentration (Type is String)
          • long_name: sea ice concentration (Type is String)
          • source: ATBD, section 3.1.4 (Type is String)
          • units: 1 (Type is String)
      • exmax_stdev_2[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height standard deviation 2 (Type is String)
          • long_name: Exmax Stdev 2 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • cloud_flag_asr[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Int16)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Cloud flag (probability) from apparent surface reflectance. 0=clear with high confidence; 1=clear with medium confidence; 2=clear with low confidence; 3=cloudy with low confidence; 4=cloudy with medium confidence; 5=cloudy with high confidence; 6=unknown (Type is String)
          • flag_meanings: clear_with_high_confidence clear_with_medium_confidence clear_with_low_confidence cloudy_with_low_confidence cloudy_with_medium_confidence cloudy_with_high_confidence unknown (Type is String)
          • flag_values: 0, 1, 2, 3, 4, 5, 6 (Type is Int16)
          • long_name: Cloud Flag ASR (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 6 (Type is Int16)
          • valid_min: 0 (Type is Int16)
      • exmax_stdev_1[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height standard deviation 1 (Type is String)
          • long_name: Exmax Stdev 1 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • fpb_corr_width[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction width (Type is String)
          • long_name: fpb correction width (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: ns (Type is String)
      • height_coarse_stdev[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height standard deviation of coarse tracker (Type is String)
          • long_name: Coarse Height Sdev (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • height_filter_05[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height fifth percentile used in the ssh height filter (Type is String)
          • long_name: Height Filter 5th Percentile (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • n_photons_used[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons in the trimmed histogram. (Type is String)
          • long_name: Number of photons used for fit (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • backgr_r_200[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background count rate, averaged over the segment based on ATLAS 50 pulse counts (Type is String)
          • long_name: Background rate 200 hz (Type is String)
          • source: ATL09 (Type is String)
          • units: hz (Type is String)
      • hist_photon_top[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: upper bound of height histogram (Type is String)
          • long_name: height histogram maximum (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • hist_w[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Segment histogram width estimate (Type is String)
          • long_name: Segment histogram width estimate (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • hist_mean_h[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean of the n_fit_photons heights (Type is String)
          • long_name: photon heights mean (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_coarse_mn[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height mean of coarse tracker (Type is String)
          • long_name: Coarse Track Height Mean (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • exmax_mean_1[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mean 1 (Type is String)
          • long_name: Exmax Mean 1 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • hist_photon_heights[ /gt2l/sea_ice_segments/delta_time= 0..221424] [ /gt2l/sea_ice_segments/stats/ds_si_hist_bins= 0..220] (Type is Int16)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Histogram of the n_fit_photons heights (Type is String)
          • long_name: photon heights histogram (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • trim_height_top[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: maximum height of trimmed photons used in the surface calculation procedure (Type is String)
          • long_name: maximum height of trimmed photons (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • exmax_mix[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mix ratio (Type is String)
          • long_name: Exmax Mix (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • asr_25[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Apparent surface reflectance at 25 hz, averaged to the sea ice segment. (Type is String)
          • long_name: Apparent Surface Reflectance 25hz (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • photon_rate[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: photon count rate, averaged over segment (Type is String)
          • long_name: photon rate (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: photons/shot (Type is String)
      • trim_height_bottom[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: minimum height of trimmed photons used in the surface calculation procedure (Type is String)
          • long_name: minimum height of trimmed photons (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • n_photons_define[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons to gather. (Type is String)
          • long_name: Number of photons defining the segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • backgr_r_25[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background count rate, averaged over the segment based on 25 hz atmosphere (Type is String)
          • long_name: Background rate 25hz (Type is String)
          • source: ATL09 (Type is String)
          • units: hz (Type is String)
    • geolocation(Type is Group)
      • attributes
        • Description: Contains parameters related to geolocation. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • rgt[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Int16)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: Reference Ground track (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1387 (Type is Int16)
          • valid_min: 1 (Type is Int16)
      • sigma_lon[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point east longitude: 1- sigma (degrees). Applies to all other photons in the group. (Type is String)
          • long_name: longitude uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (Type is String)
      • ref_atm_delay[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Atmospheric path delay, in range, for the reference photon. (Type is String)
          • long_name: Reference Photon Atm. Path Delay (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • beam_azimuth[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: The direction, eastwards from north, of the laser beam vector as seen by an observer at the laser ground spot viewing toward the spacecraft (i.e., the vector from the ground to the spacecraft). When the spacecraft is precisely at the geodetic zenith, the value will be 99999 degrees. (Type is String)
          • long_name: beam azimuth (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees_east (Type is String)
      • solar_azimuth[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • contentType: physicalMeansurement (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: solar azimuth (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees_east (Type is String)
      • ref_atm_delay_derivative[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Atmospheric path delay derivative with respect to ellipsoid for the reference photon, in meters per meter. (Type is String)
          • long_name: Derivative of Atm. Path Delay (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters/meter (Type is String)
      • sigma_lat[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point geodetic latitude: 1- sigma (degrees). Applies to all other photons in the group (Type is String)
          • long_name: latitude uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • beam_coelev[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: beam co-elevation (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (Type is String)
      • sigma_h[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m). Error estimates for all other photons in the group are computed with the scale defined below. (Type is String)
          • long_name: height uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • solar_elevation[ /gt2l/sea_ice_segments/delta_time= 0..221424] (Type is Float32)
        • attributes
          • contentType: physicalMeansurement (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: solar elevation (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (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)
  • release[ 0..0] (Type is String)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: Release number of the granule. The release number is incremented when the software or ancillary data used to create the granule has been changed. (Type is String)
      • long_name: Release Number (Type is String)
      • source: Operations (Type is String)
      • units: 1 (Type is String)
  • end_geoseg[ 0..0] (Type is Int32)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: The ending geolocation segment number associated with the data contained within this granule. ICESat granule geographic regions are further refined by geolocation segments. During the geolocation process, a geolocation segment is created approximately every 20m from the start of the orbit to the end. The geolocation segments help align the ATLAS strong a weak beams and provide a common segment length for the L2 and higher products. The geolocation segment indices differ slightly from orbit-to-orbit because of the irregular shape of the Earth. The geolocation segment indices on ATL01 and ATL02 are only approximate because beams have not been aligned at the time of their creation. (Type is String)
      • long_name: Ending Geolocation Segment (Type is String)
      • source: Derived (Type is String)
      • units: 1 (Type is String)
  • version[ 0..0] (Type is String)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: Version number of this granule within the release. It is a sequential number corresponding to the number of times the granule has been reprocessed for the current release. (Type is String)
      • long_name: Version (Type is String)
      • source: Operations (Type is String)
      • units: 1 (Type is String)
  • end_region[ 0..0] (Type is Int32)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: The ending product-specific region number associated with the data contained within this granule. ICESat-2 data products are separated by geographic regions. The data contained within a specific region are the same for ATL01 and ATL02. ATL03 regions differ slightly because of different geolocation segment locations caused by the irregular shape of the Earth. The region indices for other products are completely independent. (Type is String)
      • long_name: Ending Region (Type is String)
      • source: Derived (Type is String)
      • units: 1 (Type is String)
  • atlas_sdp_gps_epoch[ 0..0] (Type is Float64)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: Number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS Standard Data Product (SDP) epoch (2018-01-01:T00.00.00.000000 UTC). Add this value to delta time parameters to compute full gps_seconds (relative to the GPS epoch) for each data point. (Type is String)
      • long_name: ATLAS Epoch Offset (Type is String)
      • source: Operations (Type is String)
      • units: seconds since 1980-01-06T00:00:00.000000Z (Type is String)
  • end_rgt[ 0..0] (Type is Int32)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: The ending reference groundtrack (RGT) number associated with the data contained within this granule. There are 1387 reference groundtrack in the ICESat-2 repeat orbit. The reference groundtrack increments each time the spacecraft completes a full orbit of the Earth and resets to 1 each time the spacecraft completes a full cycle. (Type is String)
      • long_name: Ending Reference Groundtrack (Type is String)
      • source: Derived (Type is String)
      • units: 1 (Type is String)
      • valid_max: 1387 (Type is Int32)
      • valid_min: 1 (Type is Int32)
  • end_delta_time[ 0..0] (Type is Float64)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: Number of GPS seconds since the ATLAS SDP epoch at the last data point in the file. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
      • long_name: ATLAS End Time (Actual) (Type is String)
      • source: Derived (Type is String)
      • standard_name: time (Type is String)
      • units: seconds since 2018-01-01 (Type is String)
  • end_orbit[ 0..0] (Type is Int32)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: The ending orbit number associated with the data contained within this granule. The orbit number increments each time the spacecraft completes a full orbit of the Earth. (Type is String)
      • long_name: Ending Orbit Number (Type is String)
      • source: Derived (Type is String)
      • units: 1 (Type is String)
  • start_cycle[ 0..0] (Type is Int32)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: The starting cycle number associated with the data contained within this granule. The cycle number is the counter of the number of 91-day repeat cycles completed by the mission. (Type is String)
      • long_name: Starting Cycle (Type is String)
      • source: Derived (Type is String)
      • units: 1 (Type is String)
      • valid_max: 99 (Type is Int32)
      • valid_min: 0 (Type is Int32)
  • data_end_utc[ 0..0] (Type is String)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • source: Derived (Type is String)
      • description: UTC (in CCSDS-A format) of the last data point within the granule. (Type is String)
      • long_name: End UTC Time of Granule (CCSDS-A, Actual) (Type is String)
      • units: 1 (Type is String)
  • control[ 0..0] (Type is String)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • units: 1 (Type is String)
      • description: PGE-specific control file used to generate this granule. To re-use, replace breaks (BR) with linefeeds. (Type is String)
      • long_name: Control File (Type is String)
      • source: Operations (Type is String)
  • start_gpssow[ 0..0] (Type is Float64)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: GPS seconds-of-week of the first data point in the granule. (Type is String)
      • long_name: Start GPS SOW of Granule (Actual) (Type is String)
      • source: Derived (Type is String)
      • units: seconds (Type is String)
  • granule_end_utc[ 0..0] (Type is String)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: Requested end time (in UTC CCSDS-A) of this granule. (Type is String)
      • long_name: End UTC Time of Granule (CCSDS-A, Requested) (Type is String)
      • source: Derived (Type is String)
      • units: 1 (Type is String)
  • end_cycle[ 0..0] (Type is Int32)
    • attributes
      • 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)
      • units: 1 (Type is String)
      • valid_max: 99 (Type is Int32)
      • valid_min: 0 (Type is Int32)
  • granule_start_utc[ 0..0] (Type is String)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: Requested start time (in UTC CCSDS-A) of this granule. (Type is String)
      • long_name: Start UTC Time of Granule (CCSDS-A, Requested) (Type is String)
      • source: Derived (Type is String)
      • units: 1 (Type is String)
  • start_delta_time[ 0..0] (Type is Float64)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: Number of GPS seconds since the ATLAS SDP epoch at the first data point in the file. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
      • long_name: ATLAS Start Time (Actual) (Type is String)
      • source: Derived (Type is String)
      • standard_name: time (Type is String)
      • units: seconds since 2018-01-01 (Type is String)
  • start_geoseg[ 0..0] (Type is Int32)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: The starting geolocation segment number associated with the data contained within this granule. ICESat granule geographic regions are further refined by geolocation segments. During the geolocation process, a geolocation segment is created approximately every 20m from the start of the orbit to the end. The geolocation segments help align the ATLAS strong a weak beams and provide a common segment length for the L2 and higher products. The geolocation segment indices differ slightly from orbit-to-orbit because of the irregular shape of the Earth. The geolocation segment indices on ATL01 and ATL02 are only approximate because beams have not been aligned at the time of their creation. (Type is String)
      • long_name: Starting Geolocation Segment (Type is String)
      • source: Derived (Type is String)
      • units: 1 (Type is String)
  • start_orbit[ 0..0] (Type is Int32)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: The starting orbit number associated with the data contained within this granule. The orbit number increments each time the spacecraft completes a full orbit of the Earth. (Type is String)
      • long_name: Starting Orbit Number (Type is String)
      • source: Derived (Type is String)
      • units: 1 (Type is String)
  • data_start_utc[ 0..0] (Type is String)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • source: Derived (Type is String)
      • description: UTC (in CCSDS-A format) of the first data point within the granule. (Type is String)
      • long_name: Start UTC Time of Granule (CCSDS-A, Actual) (Type is String)
      • units: 1 (Type is String)
  • end_gpsweek[ 0..0] (Type is Int32)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: GPS week number of the last data point in the granule. (Type is String)
      • long_name: Ending GPSWeek of Granule (Actual) (Type is String)
      • source: Derived (Type is String)
      • units: weeks from 1980-01-06 (Type is String)
  • start_rgt[ 0..0] (Type is Int32)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: The starting reference groundtrack (RGT) number associated with the data contained within this granule. There are 1387 reference groundtrack in the ICESat-2 repeat orbit. The reference groundtrack increments each time the spacecraft completes a full orbit of the Earth and resets to 1 each time the spacecraft completes a full cycle. (Type is String)
      • long_name: Starting Reference Groundtrack (Type is String)
      • source: Derived (Type is String)
      • units: 1 (Type is String)
      • valid_max: 1387 (Type is Int32)
      • valid_min: 1 (Type is Int32)
  • end_gpssow[ 0..0] (Type is Float64)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: GPS seconds-of-week of the last data point in the granule. (Type is String)
      • long_name: Ending GPS SOW of Granule (Actual) (Type is String)
      • source: Derived (Type is String)
      • units: seconds (Type is String)
  • qa_at_interval[ 0..0] (Type is Float64)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: Statistics time interval for along-track QA data. (Type is String)
      • long_name: QA Along-Track Interval (Type is String)
      • source: control (Type is String)
      • units: 1 (Type is String)
  • start_region[ 0..0] (Type is Int32)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: The starting product-specific region number associated with the data contained within this granule. ICESat-2 data products are separated by geographic regions. The data contained within a specific region are the same for ATL01 and ATL02. ATL03 regions differ slightly because of different geolocation segment locations caused by the irregular shape of the Earth. The region indices for other products are completely independent. (Type is String)
      • long_name: Starting Region (Type is String)
      • source: Derived (Type is String)
      • units: 1 (Type is String)
  • start_gpsweek[ 0..0] (Type is Int32)
    • attributes
      • contentType: auxiliaryInformation (Type is String)
      • description: GPS week number of the first data point in the granule. (Type is String)
      • long_name: Start GPSWeek of Granule (Actual) (Type is String)
      • source: Derived (Type is String)
      • units: weeks from 1980-01-06 (Type is String)
  • fine_surface_finding(Type is Group)
    • attributes
      • Description: Contains ancillary parameters related to the fine surface finding algorithm. (Type is String)
    • tep_used_gt1_strong[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: TEP used in table generation for strong beam of ground track 1 (1 or 3) (Type is String)
        • long_name: TEP Table PCE1_Strong (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • h_diff_limit[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Maximum height difference between the two weighted Gaussian mean from the initial tracked height (units = meters) (Type is String)
        • long_name: Max Ht Difference (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • n_specular[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Specular returns limits (Type is String)
        • long_name: number photons Specular returns (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • tep_used_gt3_strong[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: TEP used in table generation for strong beam of ground track 3 (1 or 3) (Type is String)
        • long_name: TEP Table PCE3_Strong (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • n_spec_scale[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Scalling parameter used for scaling value of N_SPECULAR for the weak beam. Specular returns for weak beam are defined as a shot having more photons than (N_SPECULAR/N_SPEC_SCALE) (Type is String)
        • long_name: Specular Scaling Value (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • ub_length_strong[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: upper bound of segment length strong beam (Type is String)
        • long_name: upper bound segment length strong (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • ub_oc_switch_weak[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Upper bound of photon rate overlapping control for weak beam when overlap is turned off (Type is String)
        • long_name: Upper bound of overlapping control for weak beam (Type is String)
        • source: ATBD section 4.2.2.4 (Type is String)
        • units: photons/shot (Type is String)
    • bin_f[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: bin size of fine histogram along track segment length (Type is String)
        • long_name: bin size of fine histogram (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • lb_oc_switch_strong[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • units: photons/shot (Type is String)
        • description: Lower bound of photon rate overlapping control for strong beam when overlap is turned off (Type is String)
        • long_name: Lower bound of overlapping control for strong beam (Type is String)
        • source: ATBD section 4.2.2.4 (Type is String)
    • lb_oc_switch_weak[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • units: photons/shot (Type is String)
        • description: Lower bound of photon rate overlapping control for weak beam when overlap is turned off (Type is String)
        • long_name: Lower bound of overlapping control for weak beam (Type is String)
        • source: ATBD section 4.2.2.4 (Type is String)
    • tep_used_gt2_strong[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: TEP used in table generation for strong beam of ground track 2 (1 or 3) (Type is String)
        • long_name: TEP Table PCE2_Strong (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • n_photon_min[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Minimum fraction of photons needed for tracking (Type is String)
        • long_name: Minimum number of photons (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • n_w[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: number of standard deviations (Type is String)
        • long_name: number of standard deviations (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • tep_used_gt3_weak[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: TEP used in table generation for weak beam of ground track 3 (1 or 3) (Type is String)
        • long_name: TEP Table PCE3_Weak (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • delta_h_tab[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: the waveform table spacing for the height (h) dimension (Type is String)
        • long_name: h table spacing (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • overlap_switch[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Use of overlapping height segments (1 = yes, 0 = no) (Type is String)
        • flag_meanings: no yes (Type is String)
        • flag_values: 0, 1 (Type is Int32)
        • long_name: Overlap Segments (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
        • valid_max: 1 (Type is Int32)
        • valid_min: 0 (Type is Int32)
    • lb_win_s[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • description: window (Ws) containing signal photons (Type is String)
        • long_name: lower bound window signal (Type is String)
        • units: meters (Type is String)
    • tep_used_gt2_weak[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: TEP used in table generation for weak beam of ground track 2 (1 or 3) (Type is String)
        • long_name: TEP Table PCE2_Weak (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • tep_used_gt1_weak[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: TEP used in table generation for weak beam of ground track 1 (1 or 3) (Type is String)
        • long_name: TEP Table PCE1_Weak (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • n_s[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: photons in W_s (Type is String)
        • long_name: number photons in W_s (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • ub_win_s[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: window (Ws) containing signal photons (Type is String)
        • long_name: upper bound window signal (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • ub_length_weak[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: upper bound of segment length weak beam (Type is String)
        • long_name: upper bound segment length weak (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • ub_h_tab[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: the waveform upper bound for the height (h) dimension (Type is String)
        • long_name: upper bound of h table (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • ub_oc_switch_strong[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Upper bound of photon rate overlapping control for strong beam when overlap is turned off (Type is String)
        • long_name: Upper bound of overlapping control for strong beam (Type is String)
        • source: ATBD section 4.2.2.4 (Type is String)
        • units: photons/shot (Type is String)
    • ub_w_tab[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: the waveform upper bound for the width (w) dimension (Type is String)
        • long_name: upper bound of w table (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • n_photon_trim[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Minimum number of photons for trimming leading/trailing bins (Type is String)
        • long_name: Min Photons (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • delta_w_tab[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: the waveform table spacing for the width (w) dimension (Type is String)
        • long_name: w table spacing (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • lb_w_tab[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: lower bound of w table (Type is String)
        • long_name: lower bound of w table (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • lb_h_tab[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: lower bound of h table (Type is String)
        • long_name: lower bound of h table (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
  • sea_ice(Type is Group)
    • attributes
      • Description: Contains ancillary parameters related to sea ice. (Type is String)
    • min_segs_count[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: ATL07 granules with less than this number of strong beam sea ice segments will be marked as failed. (Type is String)
        • long_name: Minimum Segments Count (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • proc_beam_pair1[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Indicates if beam pair 1 was processed. (Type is String)
        • flag_meanings: not_processed processed (Type is String)
        • flag_values: 0, 1 (Type is Int32)
        • long_name: Processing Flag for Beam Pair 1 (Type is String)
        • source: Operations (Type is String)
        • units: 1 (Type is String)
        • valid_max: 1 (Type is Int32)
        • valid_min: 0 (Type is Int32)
    • proc_beam_pair3[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Indicates if beam pair 3 was processed. (Type is String)
        • flag_meanings: not_processed processed (Type is String)
        • flag_values: 0, 1 (Type is Int32)
        • long_name: Processing Flag for Beam Pair 3 (Type is String)
        • source: Operations (Type is String)
        • units: 1 (Type is String)
        • valid_max: 1 (Type is Int32)
        • valid_min: 0 (Type is Int32)
    • geoseg_min[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Indicates the minimum segment_id to process (if specified in control) (Type is String)
        • long_name: Minimum Segment ID (Type is String)
        • source: Operations (Type is String)
        • units: 1 (Type is String)
    • proc_interval[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: The number of 20 meter segments of data processed in one chunk (Type is String)
        • long_name: Processing interval (Type is String)
        • source: Operations (Type is String)
        • units: 1 (Type is String)
    • proc_beam_pair2[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Indicates if beam pair 2 was processed. (Type is String)
        • flag_meanings: not_processed processed (Type is String)
        • flag_values: 0, 1 (Type is Int32)
        • long_name: Processing Flag for Beam Pair 2 (Type is String)
        • source: Operations (Type is String)
        • units: 1 (Type is String)
        • valid_max: 1 (Type is Int32)
        • valid_min: 0 (Type is Int32)
    • geoseg_max[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Indicates the maximum segment_id to process (if specified in control). The actual maximum processed may be greater than specified. (Type is String)
        • long_name: Maximum Segment Id (Type is String)
        • source: Operations (Type is String)
        • units: 1 (Type is String)
    • region[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: The index to the geographic region covered within this granule (0=no region boundaries enforced). (Type is String)
        • long_name: Region Index (Type is String)
        • source: Operations (Type is String)
        • units: 1 (Type is String)
  • coarse_surface_finding(Type is Group)
    • attributes
      • Description: Contains ancillary parameters related to the coarse surface finding algorithm. (Type is String)
    • bin_c[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: bin size of coarse histogram (Type is String)
        • long_name: bin size coarse histogram (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • coarse_ub_wins[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Upper bound for signal photons when performing coarse tracking (Type is String)
        • long_name: Coarse_UpperBounds (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • th_pc[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: percentage cloud cover coarse (Type is String)
        • long_name: threshold percentage cloud cover coarse (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • coarse_lb_wins[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Lower bound for signal photons when performing coarse tracking (Type is String)
        • long_name: Coarse_LowerrBounds (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • l[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: along track segment length coarse (Type is String)
        • long_name: segment length coarse (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • th_d_bot[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • description: Bottom distance from mode coarse (Type is String)
        • long_name: Bottom threshold distance from mode coarse (Type is String)
        • units: meters (Type is String)
    • th_fm[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • description: fraction of histogram peak coarse (Type is String)
        • long_name: threshold fraction of peak coarse (Type is String)
        • units: 1 (Type is String)
    • n_ph_min[ 0..0] (Type is Int32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Minimum number of photons required for coarse track segment (Type is String)
        • long_name: Minimum Number of Photons (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • si_conc_min[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • description: Minimum sea ice concentration percentage value for which to process data. (Type is String)
        • long_name: Min SI Concentration Thresh (Type is String)
        • units: 1 (Type is String)
    • th_d_top[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Top distance from mode coarse (Type is String)
        • long_name: Top threshold distance from mode coarse (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • th_tc[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: height deviations from surface or adjacent strong beam (Type is String)
        • long_name: Threshold height deviations (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
  • surface_classification(Type is Group)
    • attributes
      • Description: Contains ancillary parameters related to the surface classification algorithm. (Type is String)
    • theta_ref[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Solar elevation normalization angle for use of normalized background rate (Type is String)
        • long_name: Solar elevation normalization angle (Type is String)
        • source: ATBD section 4.3.1.4 (Type is String)
        • units: degrees (Type is String)
    • height_pct[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Percentile of sorted heights (Type is String)
        • long_name: Percentile Hts (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: percentile (Type is String)
    • w1[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: max width (dark smooth lead) (Type is String)
        • long_name: max width (dark smooth lead) (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • beam_gain[ 0..5] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: Relative gains for beams 1 through 6 where N is the beam number (Note: Beams 1, 3, and 5 are the strong beams) (Type is String)
        • long_name: relative beam gain for beams 1 through 6 (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • p3[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: photon rate (shadow) (Type is String)
        • long_name: pr (shadow) (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • b1[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: max backgr (gray ice) (Type is String)
        • long_name: max backgr (gray ice) (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • p4[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: photon rate (specular) (Type is String)
        • long_name: pr (specular) (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • w2[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: max width (dark rough lead) (Type is String)
        • long_name: max width (dark rough lead) (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • theta_cntl[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • description: Solar elevation for controlling use of background rate (Type is String)
        • long_name: Solar elevation for use of background rate (Type is String)
        • units: 1 (Type is String)
    • theta_nlb[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • units: degrees (Type is String)
        • description: Solar elevation normalization lower bound for use of normalized background rate (Type is String)
        • long_name: Solar elevation normalization lower bound (Type is String)
        • source: ATBD section 4.3.1.4 (Type is String)
    • p1[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: photon rate (clouds) (Type is String)
        • long_name: pr (clouds) (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • p2[ 0..0] (Type is Float32)
      • attributes
        • contentType: auxiliaryInformation (Type is String)
        • description: photon rate (snow) (Type is String)
        • long_name: pr (snow) (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
gt3r(Type is Group)
  • attributes
    • Description: This ground contains parameters and subgroups related a specific groundtrack. (Type is String)
    • data_rate: Each subgroup identifies its particular data rate. (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)
  • sea_ice_segments(Type is Group)
    • attributes
      • Description: Top group for sea ice segments as computed by the ATBD aglorithm (Type is String)
      • data_rate: Data within this group are stored at the variable segment rate. (Type is String)
    Dimensions: [ /gt3r/sea_ice_segments/delta_time = 0..278029 ]
    • latitude[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time longitude (Type is String)
        • description: Latitude, WGS84, North=+, Lat of segment center (Type is String)
        • long_name: Latitude (Type is String)
        • source: ATBD, section 4.4 (Type is String)
        • standard_name: latitude (Type is String)
        • units: degrees_north (Type is String)
        • valid_max: 90. (Type is Float64)
        • valid_min: -90. (Type is Float64)
    • delta_time[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float64)
      • attributes
        • contentType: physicalMeasurement (Type is String)
        • coordinates: latitude longitude (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)
        • long_name: Elapsed GPS seconds (Type is String)
        • source: telemetry (Type is String)
        • standard_name: time (Type is String)
        • units: seconds since 2018-01-01 (Type is String)
    • longitude[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude (Type is String)
        • description: Longitude, WGS84, East=+,Lon of segment center (Type is String)
        • long_name: Longitude (Type is String)
        • source: ATBD, section 4.4 (Type is String)
        • standard_name: longitude (Type is String)
        • units: degrees_east (Type is String)
        • valid_max: 180. (Type is Float64)
        • valid_min: -180. (Type is Float64)
    • height_segment_id[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Identifier of each height segment (Type is String)
        • long_name: Identifier of each height segment (Type is String)
        • source: ATBD, section 5.2 (Type is String)
        • units: 1 (Type is String)
    • geoseg_beg[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Geolocation segment (geoseg) ID associated with the first photon used in this sea ice segment (Type is String)
        • long_name: Beginning GEOSEG (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • seg_dist_x[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float64)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Along-track distance from the equator crossing to the segment center. (Type is String)
        • long_name: Along track distance (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: meters (Type is String)
    • geoseg_end[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Int32)
      • attributes
        • contentType: referenceInformation (Type is String)
        • coordinates: delta_time latitude longitude (Type is String)
        • description: Geolocation segment (geoseg) ID associated with the last photon used in this sea ice segment (Type is String)
        • long_name: Ending GEOSEG (Type is String)
        • source: Sea Ice ATBD (Type is String)
        • units: 1 (Type is String)
    • heights(Type is Group)
      • attributes
        • Description: Contains parameters relating to the calculated surface height for one Ground Track. As ICESat-2 orbits the earth, sequential transmit pulses illuminate six ground tracks on the surface of the earth. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • height_segment_fit_quality_flag[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Int8)
        • attributes
          • _FillValue: -1 (Type is Int8)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Flag describing the quality of the results of the along-track fit. (-1=height value is invalid; 1=ngrid_w < wlength/2; 2=ngrid_w >= wlength/2; 3=ngrid_dt < dtlength/2; 4=ngrid_dt >= dtlength/2; 5=ngrid_dt >= (dtlength-2): where 1 is best and 5 is poor). Heights are reported even if this flag indicates the height is invalid. (Type is String)
          • flag_meanings: invalid best high med low poor (Type is String)
          • flag_values: -1, 1, 2, 3, 4, 5 (Type is Int8)
          • long_name: height Quality Flag (Type is String)
          • source: ATBD, section 4.2.4.2 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 5 (Type is Int8)
          • valid_min: -1 (Type is Int8)
      • height_segment_length_seg[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: along-track length of segment containing n_photons_actual (Type is String)
          • long_name: length of segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_asr_calc[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Computed apparent surface reflectance for the sea ice segment. (Type is String)
          • long_name: Calculated Apparent Surface Reflectivity (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • height_segment_quality[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Height segment quality flag, 1 is good quality, 0 is bad depending on fit, wguassian, or layer flag (Type is String)
          • flag_meanings: bad_quality good_quality (Type is String)
          • flag_values: 0, 1 (Type is Int8)
          • long_name: Height Segment Quality Flag (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_n_pulse_seg[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Int32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: number of laser pulses (Type is String)
          • long_name: number of laser pulses (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • across_track_distance[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Across track distance of photons averaged over the sea ice height segment. (Type is String)
          • long_name: Across Track Distance (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_htcorr_skew[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height corection for skew (Type is String)
          • long_name: Height Correction for Skew (Type is String)
          • source: ATBD, section 4.2.6 (Type is String)
          • units: meters (Type is String)
      • height_segment_ssh_flag[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Identifies the height segments that are candidates for use as sea surface reference in freeboard calculations in ATL10. 0 = sea ice; 1 = sea surface (Type is String)
          • flag_meanings: sea_ice sea_surface (Type is String)
          • flag_values: 0, 1 (Type is Int8)
          • long_name: Sea Surface Flag (Type is String)
          • source: ATBD, section 4.3 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_height[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean height from along-track segment fit detremined by the sea ice algorithm (Type is String)
          • long_name: height of segment surface (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
      • height_segment_type[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Int8)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Value that indicates segment surface type as sea ice or different types of sea surface. 0=cloud covered: rsurf (Type is String)
          • flag_meanings: cloud_covered other specular_lead_low_w_bkg specular_lead_low specular_lead_high_w_bkg specular_lead_high dark_lead_smooth_w_bkg dark_lead_smooth dark_lead_rough_w_bkg dark_lead_rough (Type is String)
          • flag_values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 (Type is Int8)
          • long_name: Segment surface type (Type is String)
          • source: ATBD, section 4.3 (Type is String)
          • units: 1 (Type is String)
          • valid_max: 9 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • height_segment_confidence[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Confidence level in the surface height estimate based on the number of photons; the background noise rate; and the error analysis (Type is String)
          • long_name: Surface height confidence (Type is String)
          • source: ATBD, section 4.2.4.2 (Type is String)
          • units: 1 (Type is String)
      • height_segment_surface_error_est[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Error estimate of the surface height (Type is String)
          • long_name: h surface error est (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_w_gaussian[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: width of best fit gaussian (Type is String)
          • long_name: width of best fit gaussian (Type is String)
          • source: ATBD, section 4.2.4 (Type is String)
          • units: meters (Type is String)
      • height_segment_rms[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: RMS difference between sea ice modeled and observed photon height distribution (Type is String)
          • long_name: height rms (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
    • geophysical(Type is Group)
      • attributes
        • Description: Contains geophysical parameters and corrections used to correct photon heights for geophysical effects, such as tides. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • height_segment_t2m[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Temperature at 2m above the displacement height (K) (Type is String)
          • long_name: temperature_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: temperature (Type is String)
          • units: K (Type is String)
      • height_segment_dac[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect. (Type is String)
          • long_name: Dynamic Atmosphere Correction (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_ps[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Sea Level Pressure (Pa) (Type is String)
          • long_name: sea level pressure (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: pressure (Type is String)
          • units: Pa (Type is String)
      • height_segment_ib[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Inverted barometer effect calculated from surface pressure (Type is String)
          • long_name: Inverted barometer effect (Type is String)
          • source: ATBD, section 4.2 (Type is String)
          • units: meters (Type is String)
      • height_segment_load[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Load Tide - Local displacement due to Ocean Loading (-6 to 0 cm). (Type is String)
          • long_name: Load Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_geoid[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Geoid height above WGS-84 reference ellipsoid (range -107 to 86m), based on the EGM2008 model. (Type is String)
          • long_name: EGM2008 Geoid (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_ocean[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Ocean Tides including diurnal and semi-diurnal (harmonic analysis), and longer period tides (dynamic and self-consistent equilibrium) (Type is String)
          • long_name: Ocean Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_v2m[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Northward wind at 2m above the displacement height (m/s-1) (Type is String)
          • long_name: Northward_wind_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: northward_wind (Type is String)
          • units: m s-1 (Type is String)
      • height_segment_mss[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean sea surface height above WGS-84 reference ellipsoid (range: -105 to 87m), based on the DTU13 model. (Type is String)
          • long_name: DTU13 Mean Sea Surface (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_u2m[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Eastward wind at 2m above the displacement height (m/s-1) (Type is String)
          • long_name: Eastward_wind_at_2m (Type is String)
          • source: ATL09 (Type is String)
          • standard_name: eastward_wind (Type is String)
          • units: m s-1 (Type is String)
      • height_segment_lpe[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Long period equilibrium tide self-consistent with ocean tide model (+-0.04m). (dependent only on time and latitude) (Type is String)
          • long_name: Equilibrium Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_earth[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Solid Earth Tide (Type is String)
          • long_name: Earth Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • height_segment_pole[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Pole Tide -Rotational deformation due to polar motion (-1.5 to 1.5 cm). (Type is String)
          • long_name: Pole Tide (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
    • stats(Type is Group)
      • attributes
        • Description: Contains parameters related to quality and corrections on the sea ice height paramters (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      Dimensions: [ /gt3r/sea_ice_segments/stats/ds_si_hist_bins = 0..220 ]
      • ds_si_hist_bins[ /gt3r/sea_ice_segments/stats/ds_si_hist_bins= 0..220] (Type is Int32)
        • attributes
          • contentType: auxiliaryInformation (Type is String)
          • description: Dimension scale indexing the sea ice histogram bins. The bin heights must be computed from information contained within the same group as the histogram. (Type is String)
          • long_name: Sea Ice Histogram Bins Dimension Scale (Type is String)
          • source: SeaIce ATBD (Type is String)
          • units: 1 (Type is String)
      • hist_median_h[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Median of the n_fit_photons heights (Type is String)
          • long_name: trimmed photon heights median (Type is String)
          • source: ATBD, section 4.2.3.1 (Type is String)
          • units: meters (Type is String)
      • height_filter_min[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height minimum used in the ssh height filter (Type is String)
          • long_name: Height Filter Min (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • cloud_flag_atm[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Int8)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of layers found from the backscatter profile using the DDA layer finder. (Type is String)
          • long_name: Cloud Flag Atm (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 10 (Type is Int8)
          • valid_min: 0 (Type is Int8)
      • fpb_avg_dt[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction average dead time (Type is String)
          • long_name: fpb correction average deadtime (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: ns (Type is String)
      • msw_flag[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Int8)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • 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)
          • long_name: Multiple Scattering Warning Flag (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 5 (Type is Int8)
          • valid_min: -1 (Type is Int8)
      • fpb_strength[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction strength (Type is String)
          • long_name: fpb correction strength (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: photons/shot (Type is String)
      • bsnow_con[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Int8)
        • attributes
          • _FillValue: 127 (Type is Int8)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Blowing snow confidence (Type is String)
          • long_name: Blowing snow confidence (Type is String)
          • source: ATL09 (Type is String)
          • units: 1 (Type is String)
      • layer_flag[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Int16)
        • attributes
          • contentType: qualityInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • flag_meanings: likely_clear likely_cloudy (Type is String)
          • flag_values: 0, 1 (Type is Int16)
          • long_name: Consolidated cloud flag (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1 (Type is Int16)
          • valid_min: 0 (Type is Int16)
      • hist_photon_bin_size[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: bin size of photon height histogram (Type is String)
          • long_name: height histogram bin size (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • backgr_calc[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Calculated background count rate based on sun angle, surface slope, unit reflectance (Type is String)
          • long_name: background count rate calculated (Type is String)
          • source: ATBD, section 4.2.3 (Type is String)
          • units: hz (Type is String)
      • fpb_corr[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated first-photon bias(fpb) correction to mean segment height (Type is String)
          • long_name: first photon bias correction (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • bsnow_h[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Blowing snow layer top height (Type is String)
          • long_name: Blowing snow top h (Type is String)
          • source: ATL09 (Type is String)
          • units: meters (Type is String)
      • hist_photon_bottom[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: lower bound of height histogram (Type is String)
          • long_name: height histogram minimum (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • background_r_norm[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background rate normalized to a fixed solar elevation angle (Type is String)
          • long_name: Normalized background (50-shot) (Type is String)
          • source: ATBD section 4.3.1.3 (Type is String)
          • units: hz (Type is String)
      • exmax_mean_2[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mean 2 (Type is String)
          • long_name: Exmax Mean 2 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • background_int_height[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: The height of the altimetric range window after subtracting the height span of the signal photon events in the 50-shot span (Type is String)
          • long_name: Height of column used in background calculation (Type is String)
          • source: ATBD, section 7.3 (Type is String)
          • units: meters (Type is String)
      • n_photons_actual[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons gathered (Type is String)
          • long_name: Number of photons found for the segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • ice_conc[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: sea ice concentration (Type is String)
          • long_name: sea ice concentration (Type is String)
          • source: ATBD, section 3.1.4 (Type is String)
          • units: 1 (Type is String)
      • exmax_stdev_2[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height standard deviation 2 (Type is String)
          • long_name: Exmax Stdev 2 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • cloud_flag_asr[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Int16)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Cloud flag (probability) from apparent surface reflectance. 0=clear with high confidence; 1=clear with medium confidence; 2=clear with low confidence; 3=cloudy with low confidence; 4=cloudy with medium confidence; 5=cloudy with high confidence; 6=unknown (Type is String)
          • flag_meanings: clear_with_high_confidence clear_with_medium_confidence clear_with_low_confidence cloudy_with_low_confidence cloudy_with_medium_confidence cloudy_with_high_confidence unknown (Type is String)
          • flag_values: 0, 1, 2, 3, 4, 5, 6 (Type is Int16)
          • long_name: Cloud Flag ASR (Type is String)
          • source: Atmosphere ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 6 (Type is Int16)
          • valid_min: 0 (Type is Int16)
      • exmax_stdev_1[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height standard deviation 1 (Type is String)
          • long_name: Exmax Stdev 1 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • fpb_corr_width[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: FPB correction width (Type is String)
          • long_name: fpb correction width (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: ns (Type is String)
      • height_coarse_stdev[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height standard deviation of coarse tracker (Type is String)
          • long_name: Coarse Height Sdev (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • height_filter_05[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height fifth percentile used in the ssh height filter (Type is String)
          • long_name: Height Filter 5th Percentile (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • n_photons_used[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons in the trimmed histogram. (Type is String)
          • long_name: Number of photons used for fit (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • backgr_r_200[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background count rate, averaged over the segment based on ATLAS 50 pulse counts (Type is String)
          • long_name: Background rate 200 hz (Type is String)
          • source: ATL09 (Type is String)
          • units: hz (Type is String)
      • hist_photon_top[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: upper bound of height histogram (Type is String)
          • long_name: height histogram maximum (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • hist_w[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Segment histogram width estimate (Type is String)
          • long_name: Segment histogram width estimate (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • hist_mean_h[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Mean of the n_fit_photons heights (Type is String)
          • long_name: photon heights mean (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • height_coarse_mn[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: height mean of coarse tracker (Type is String)
          • long_name: Coarse Track Height Mean (Type is String)
          • source: sea ice ATBD , sect 4.2.1.2 (Type is String)
          • units: meters (Type is String)
      • exmax_mean_1[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mean 1 (Type is String)
          • long_name: Exmax Mean 1 (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • hist_photon_heights[ /gt3r/sea_ice_segments/delta_time= 0..278029] [ /gt3r/sea_ice_segments/stats/ds_si_hist_bins= 0..220] (Type is Int16)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Histogram of the n_fit_photons heights (Type is String)
          • long_name: photon heights histogram (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • trim_height_top[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: maximum height of trimmed photons used in the surface calculation procedure (Type is String)
          • long_name: maximum height of trimmed photons (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • exmax_mix[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: modelResult (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: exmax height mix ratio (Type is String)
          • long_name: Exmax Mix (Type is String)
          • source: sea ice ATBD Appendix E (Type is String)
          • units: meters (Type is String)
      • asr_25[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Apparent surface reflectance at 25 hz, averaged to the sea ice segment. (Type is String)
          • long_name: Apparent Surface Reflectance 25hz (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • photon_rate[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: photon count rate, averaged over segment (Type is String)
          • long_name: photon rate (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: photons/shot (Type is String)
      • trim_height_bottom[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: minimum height of trimmed photons used in the surface calculation procedure (Type is String)
          • long_name: minimum height of trimmed photons (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: meters (Type is String)
      • n_photons_define[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Int16)
        • attributes
          • _FillValue: -1 (Type is Int16)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Number of photons to gather. (Type is String)
          • long_name: Number of photons defining the segment (Type is String)
          • source: ATBD, section 4.2.2.4 (Type is String)
          • units: 1 (Type is String)
      • backgr_r_25[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Background count rate, averaged over the segment based on 25 hz atmosphere (Type is String)
          • long_name: Background rate 25hz (Type is String)
          • source: ATL09 (Type is String)
          • units: hz (Type is String)
    • geolocation(Type is Group)
      • attributes
        • Description: Contains parameters related to geolocation. (Type is String)
        • data_rate: Data within this group are stored at the sea_ice_height segment rate. (Type is String)
      • rgt[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Int16)
        • attributes
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: Reference Ground track (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
          • valid_max: 1387 (Type is Int16)
          • valid_min: 1 (Type is Int16)
      • sigma_lon[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point east longitude: 1- sigma (degrees). Applies to all other photons in the group. (Type is String)
          • long_name: longitude uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (Type is String)
      • ref_atm_delay[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Atmospheric path delay, in range, for the reference photon. (Type is String)
          • long_name: Reference Photon Atm. Path Delay (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters (Type is String)
      • beam_azimuth[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: The direction, eastwards from north, of the laser beam vector as seen by an observer at the laser ground spot viewing toward the spacecraft (i.e., the vector from the ground to the spacecraft). When the spacecraft is precisely at the geodetic zenith, the value will be 99999 degrees. (Type is String)
          • long_name: beam azimuth (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees_east (Type is String)
      • solar_azimuth[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • contentType: physicalMeansurement (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: solar azimuth (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees_east (Type is String)
      • ref_atm_delay_derivative[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Atmospheric path delay derivative with respect to ellipsoid for the reference photon, in meters per meter. (Type is String)
          • long_name: Derivative of Atm. Path Delay (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: meters/meter (Type is String)
      • sigma_lat[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point geodetic latitude: 1- sigma (degrees). Applies to all other photons in the group (Type is String)
          • long_name: latitude uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • beam_coelev[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: beam co-elevation (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (Type is String)
      • sigma_h[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • _FillValue: 3.402823466e+38 (Type is Float32)
          • contentType: referenceInformation (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (Type is String)
          • description: Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m). Error estimates for all other photons in the group are computed with the scale defined below. (Type is String)
          • long_name: height uncertainty (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: 1 (Type is String)
      • solar_elevation[ /gt3r/sea_ice_segments/delta_time= 0..278029] (Type is Float32)
        • attributes
          • contentType: physicalMeansurement (Type is String)
          • coordinates: ../delta_time ../latitude ../longitude (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)
          • long_name: solar elevation (Type is String)
          • source: Sea Ice ATBD (Type is String)
          • units: degrees (Type is String)
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