Attributes { HDF5_ROOT_GROUP { orbit_info { String Dataset "crossing_time", "cycle_number", "orbit_number", "rgt", "sc_orient", "sc_orient_time", "lan"; } METADATA { AcquisitionInformation { lidar { } lidarDocument { } platform { } platformDocument { } } DataQuality { CompletenessOmission { } DomainConsistency { } } ProductSpecificationDocument { } SeriesIdentification { } DatasetIdentification { } Extent { } QADatasetIdentification { } Lineage { ANC38-07 { } Control { } ANC02-02 { } ANC25-07 { } ANC15 { } ANC26-07 { } ANC36-07 { } ATL03 { } ATL09 { } ANC31 { } ANC19 { } } ProcessStep { Browse { } Metadata { } PGE { } QA { } } } gt1r { sea_ice_segments { heights { String Dataset "height_segment_fit_quality_flag", "height_segment_length_seg", "height_segment_asr_calc", "height_segment_quality", "height_segment_n_pulse_seg", "across_track_distance", "height_segment_htcorr_skew", "height_segment_ssh_flag", "height_segment_height", "height_segment_type", "height_segment_confidence", "height_segment_surface_error_est", "height_segment_w_gaussian", "height_segment_rms"; } String Dataset "height_segment_id", "seg_dist_x", "longitude", "latitude", "geoseg_beg", "delta_time", "geoseg_end"; geophysical { String Dataset "height_segment_t2m", "height_segment_dac", "height_segment_ps", "height_segment_ib", "height_segment_load", "height_segment_geoid", "height_segment_ocean", "height_segment_v2m", "height_segment_mss", "height_segment_u2m", "height_segment_lpe", "height_segment_earth", "height_segment_pole"; } stats { String Dataset "msw_flag", "hist_median_h", "height_filter_min", "cloud_flag_atm", "fpb_avg_dt", "ds_si_hist_bins", "fpb_strength", "bsnow_con", "layer_flag", "hist_photon_bin_size", "backgr_calc", "fpb_corr", "bsnow_h", "hist_photon_bottom", "background_r_norm", "exmax_mean_2", "background_int_height", "n_photons_actual", "ice_conc", "exmax_stdev_2", "cloud_flag_asr", "exmax_stdev_1", "fpb_corr_width", "height_coarse_stdev", "height_filter_05", "n_photons_used", "backgr_r_200", "hist_photon_top", "hist_w", "hist_mean_h", "height_coarse_mn", "exmax_mean_1", "hist_photon_heights", "trim_height_top", "exmax_mix", "asr_25", "photon_rate", "trim_height_bottom", "n_photons_define", "backgr_r_25"; } geolocation { String Dataset "rgt", "sigma_lon", "ref_atm_delay", "beam_azimuth", "solar_azimuth", "ref_atm_delay_derivative", "sigma_lat", "beam_coelev", "sigma_h", "solar_elevation"; } } } gt2r { sea_ice_segments { heights { String Dataset "height_segment_fit_quality_flag", "height_segment_length_seg", "height_segment_asr_calc", "height_segment_quality", "height_segment_n_pulse_seg", "across_track_distance", "height_segment_htcorr_skew", "height_segment_ssh_flag", "height_segment_height", "height_segment_type", "height_segment_confidence", "height_segment_surface_error_est", "height_segment_w_gaussian", "height_segment_rms"; } String Dataset "height_segment_id", "seg_dist_x", "longitude", "latitude", "geoseg_beg", "delta_time", "geoseg_end"; geophysical { String Dataset "height_segment_t2m", "height_segment_dac", "height_segment_ps", "height_segment_ib", "height_segment_load", "height_segment_geoid", "height_segment_ocean", "height_segment_v2m", "height_segment_mss", "height_segment_u2m", "height_segment_lpe", "height_segment_earth", "height_segment_pole"; } stats { String Dataset "msw_flag", "hist_median_h", "height_filter_min", "cloud_flag_atm", "fpb_avg_dt", "ds_si_hist_bins", "fpb_strength", "bsnow_con", "layer_flag", "hist_photon_bin_size", "backgr_calc", "fpb_corr", "bsnow_h", "hist_photon_bottom", "background_r_norm", "exmax_mean_2", "background_int_height", "n_photons_actual", "ice_conc", "exmax_stdev_2", "cloud_flag_asr", "exmax_stdev_1", "fpb_corr_width", "height_coarse_stdev", "height_filter_05", "n_photons_used", "backgr_r_200", "hist_photon_top", "hist_w", "hist_mean_h", "height_coarse_mn", "exmax_mean_1", "hist_photon_heights", "trim_height_top", "exmax_mix", "asr_25", "photon_rate", "trim_height_bottom", "n_photons_define", "backgr_r_25"; } geolocation { String Dataset "rgt", "sigma_lon", "ref_atm_delay", "beam_azimuth", "solar_azimuth", "ref_atm_delay_derivative", "sigma_lat", "beam_coelev", "sigma_h", "solar_elevation"; } } } gt1l { sea_ice_segments { heights { String Dataset "height_segment_fit_quality_flag", "height_segment_length_seg", "height_segment_asr_calc", "height_segment_quality", "height_segment_n_pulse_seg", "across_track_distance", "height_segment_htcorr_skew", "height_segment_ssh_flag", "height_segment_height", "height_segment_type", "height_segment_confidence", "height_segment_surface_error_est", "height_segment_w_gaussian", "height_segment_rms"; } String Dataset "height_segment_id", "seg_dist_x", "longitude", "latitude", "geoseg_beg", "delta_time", "geoseg_end"; geophysical { String Dataset "height_segment_t2m", "height_segment_dac", "height_segment_ps", "height_segment_ib", "height_segment_load", "height_segment_geoid", "height_segment_ocean", "height_segment_v2m", "height_segment_mss", "height_segment_u2m", "height_segment_lpe", "height_segment_earth", "height_segment_pole"; } stats { String Dataset "msw_flag", "hist_median_h", "height_filter_min", "cloud_flag_atm", "fpb_avg_dt", "ds_si_hist_bins", "fpb_strength", "bsnow_con", "layer_flag", "hist_photon_bin_size", "backgr_calc", "fpb_corr", "bsnow_h", "hist_photon_bottom", "background_r_norm", "exmax_mean_2", "background_int_height", "n_photons_actual", "ice_conc", "exmax_stdev_2", "cloud_flag_asr", "exmax_stdev_1", "fpb_corr_width", "height_coarse_stdev", "height_filter_05", "n_photons_used", "backgr_r_200", "hist_photon_top", "hist_w", "hist_mean_h", "height_coarse_mn", "exmax_mean_1", "hist_photon_heights", "trim_height_top", "exmax_mix", "asr_25", "photon_rate", "trim_height_bottom", "n_photons_define", "backgr_r_25"; } geolocation { String Dataset "rgt", "sigma_lon", "ref_atm_delay", "beam_azimuth", "solar_azimuth", "ref_atm_delay_derivative", "sigma_lat", "beam_coelev", "sigma_h", "solar_elevation"; } } } quality_assessment { String Dataset "qa_granule_fail_reason", "qa_granule_pass_fail"; } gt3l { sea_ice_segments { heights { String Dataset "height_segment_fit_quality_flag", "height_segment_length_seg", "height_segment_asr_calc", "height_segment_quality", "height_segment_n_pulse_seg", "across_track_distance", "height_segment_htcorr_skew", "height_segment_ssh_flag", "height_segment_height", "height_segment_type", "height_segment_confidence", "height_segment_surface_error_est", "height_segment_w_gaussian", "height_segment_rms"; } String Dataset "height_segment_id", "seg_dist_x", "longitude", "latitude", "geoseg_beg", "delta_time", "geoseg_end"; geophysical { String Dataset "height_segment_t2m", "height_segment_dac", "height_segment_ps", "height_segment_ib", "height_segment_load", "height_segment_geoid", "height_segment_ocean", "height_segment_v2m", "height_segment_mss", "height_segment_u2m", "height_segment_lpe", "height_segment_earth", "height_segment_pole"; } stats { String Dataset "msw_flag", "hist_median_h", "height_filter_min", "cloud_flag_atm", "fpb_avg_dt", "ds_si_hist_bins", "fpb_strength", "bsnow_con", "layer_flag", "hist_photon_bin_size", "backgr_calc", "fpb_corr", "bsnow_h", "hist_photon_bottom", "background_r_norm", "exmax_mean_2", "background_int_height", "n_photons_actual", "ice_conc", "exmax_stdev_2", "cloud_flag_asr", "exmax_stdev_1", "fpb_corr_width", "height_coarse_stdev", "height_filter_05", "n_photons_used", "backgr_r_200", "hist_photon_top", "hist_w", "hist_mean_h", "height_coarse_mn", "exmax_mean_1", "hist_photon_heights", "trim_height_top", "exmax_mix", "asr_25", "photon_rate", "trim_height_bottom", "n_photons_define", "backgr_r_25"; } geolocation { String Dataset "rgt", "sigma_lon", "ref_atm_delay", "beam_azimuth", "solar_azimuth", "ref_atm_delay_derivative", "sigma_lat", "beam_coelev", "sigma_h", "solar_elevation"; } } } gt2l { sea_ice_segments { heights { String Dataset "height_segment_fit_quality_flag", "height_segment_length_seg", "height_segment_asr_calc", "height_segment_quality", "height_segment_n_pulse_seg", "across_track_distance", "height_segment_htcorr_skew", "height_segment_ssh_flag", "height_segment_height", "height_segment_type", "height_segment_confidence", "height_segment_surface_error_est", "height_segment_w_gaussian", "height_segment_rms"; } String Dataset "height_segment_id", "seg_dist_x", "longitude", "latitude", "geoseg_beg", "delta_time", "geoseg_end"; geophysical { String Dataset "height_segment_t2m", "height_segment_dac", "height_segment_ps", "height_segment_ib", "height_segment_load", "height_segment_geoid", "height_segment_ocean", "height_segment_v2m", "height_segment_mss", "height_segment_u2m", "height_segment_lpe", "height_segment_earth", "height_segment_pole"; } stats { String Dataset "msw_flag", "hist_median_h", "height_filter_min", "cloud_flag_atm", "fpb_avg_dt", "ds_si_hist_bins", "fpb_strength", "bsnow_con", "layer_flag", "hist_photon_bin_size", "backgr_calc", "fpb_corr", "bsnow_h", "hist_photon_bottom", "background_r_norm", "exmax_mean_2", "background_int_height", "n_photons_actual", "ice_conc", "exmax_stdev_2", "cloud_flag_asr", "exmax_stdev_1", "fpb_corr_width", "height_coarse_stdev", "height_filter_05", "n_photons_used", "backgr_r_200", "hist_photon_top", "hist_w", "hist_mean_h", "height_coarse_mn", "exmax_mean_1", "hist_photon_heights", "trim_height_top", "exmax_mix", "asr_25", "photon_rate", "trim_height_bottom", "n_photons_define", "backgr_r_25"; } geolocation { String Dataset "rgt", "sigma_lon", "ref_atm_delay", "beam_azimuth", "solar_azimuth", "ref_atm_delay_derivative", "sigma_lat", "beam_coelev", "sigma_h", "solar_elevation"; } } } ancillary_data { String Dataset "release", "end_geoseg", "version", "end_region", "atlas_sdp_gps_epoch", "end_rgt", "end_delta_time", "end_orbit", "start_cycle", "data_end_utc", "control", "start_gpssow", "granule_end_utc", "end_cycle", "granule_start_utc", "start_delta_time", "start_geoseg", "start_orbit", "data_start_utc", "end_gpsweek", "start_rgt", "end_gpssow", "qa_at_interval", "start_region", "start_gpsweek"; fine_surface_finding { String Dataset "tep_used_gt1_strong", "h_diff_limit", "n_specular", "tep_used_gt3_strong", "n_spec_scale", "ub_length_strong", "ub_oc_switch_weak", "bin_f", "lb_oc_switch_strong", "lb_oc_switch_weak", "tep_used_gt2_strong", "n_photon_min", "n_w", "tep_used_gt3_weak", "delta_h_tab", "overlap_switch", "lb_win_s", "tep_used_gt2_weak", "tep_used_gt1_weak", "n_s", "ub_win_s", "ub_length_weak", "ub_h_tab", "ub_oc_switch_strong", "ub_w_tab", "n_photon_trim", "delta_w_tab", "lb_w_tab", "lb_h_tab"; } sea_ice { String Dataset "min_segs_count", "proc_beam_pair1", "proc_beam_pair3", "geoseg_min", "proc_interval", "proc_beam_pair2", "geoseg_max", "region"; } coarse_surface_finding { String Dataset "bin_c", "coarse_ub_wins", "th_pc", "coarse_lb_wins", "l", "th_d_bot", "th_fm", "n_ph_min", "si_conc_min", "th_d_top", "th_tc"; } surface_classification { String Dataset "theta_ref", "height_pct", "w1", "beam_gain", "p3", "b1", "p4", "w2", "theta_cntl", "theta_nlb", "p1", "p2"; } } gt3r { sea_ice_segments { heights { String Dataset "height_segment_fit_quality_flag", "height_segment_length_seg", "height_segment_asr_calc", "height_segment_quality", "height_segment_n_pulse_seg", "across_track_distance", "height_segment_htcorr_skew", "height_segment_ssh_flag", "height_segment_height", "height_segment_type", "height_segment_confidence", "height_segment_surface_error_est", "height_segment_w_gaussian", "height_segment_rms"; } String Dataset "height_segment_id", "seg_dist_x", "longitude", "latitude", "geoseg_beg", "delta_time", "geoseg_end"; geophysical { String Dataset "height_segment_t2m", "height_segment_dac", "height_segment_ps", "height_segment_ib", "height_segment_load", "height_segment_geoid", "height_segment_ocean", "height_segment_v2m", "height_segment_mss", "height_segment_u2m", "height_segment_lpe", "height_segment_earth", "height_segment_pole"; } stats { String Dataset "msw_flag", "hist_median_h", "height_filter_min", "cloud_flag_atm", "fpb_avg_dt", "ds_si_hist_bins", "fpb_strength", "bsnow_con", "layer_flag", "hist_photon_bin_size", "backgr_calc", "fpb_corr", "bsnow_h", "hist_photon_bottom", "background_r_norm", "exmax_mean_2", "background_int_height", "n_photons_actual", "ice_conc", "exmax_stdev_2", "cloud_flag_asr", "exmax_stdev_1", "fpb_corr_width", "height_coarse_stdev", "height_filter_05", "n_photons_used", "backgr_r_200", "hist_photon_top", "hist_w", "hist_mean_h", "height_coarse_mn", "exmax_mean_1", "hist_photon_heights", "trim_height_top", "exmax_mix", "asr_25", "photon_rate", "trim_height_bottom", "n_photons_define", "backgr_r_25"; } geolocation { String Dataset "rgt", "sigma_lon", "ref_atm_delay", "beam_azimuth", "solar_azimuth", "ref_atm_delay_derivative", "sigma_lat", "beam_coelev", "sigma_h", "solar_elevation"; } } } } H5_GLOBAL { String HDF5_OBJ_FULLPATH "H5_GLOBAL"; String Conventions "CF-1.6"; 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)"; String contributor_role "Instrument Engineer, Investigator, Principle Investigator, Data Producer, Data Producer"; String date_type "UTC"; 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"; String featureType "trajectory"; String geospatial_lat_units "degrees_north"; String geospatial_lon_units "degrees_east"; String granule_type "ATL07"; String identifier_product_doi_authority "http://dx.doi.org"; String level "L3A"; 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."; String naming_authority "http://dx.doi.org"; String short_name "ATL07"; String spatial_coverage_type "Horizontal"; String standard_name_vocabulary "CF-1.6"; String time_type "CCSDS UTC-A"; String title "SET_BY_META"; String date_created "2020-05-29T14:35:54.000000Z"; String hdfversion "HDF5 1.10.3"; String history "2020-05-29T14:35:54.000000Z;2bed11f8-37e3-3547-bf60-9d7af1919f0d;Created by PGE atlas_l3a_si Version 4.3.2"; String identifier_file_uuid "2bed11f8-37e3-3547-bf60-9d7af1919f0d"; String identifier_product_format_version "4.3"; Float64 time_coverage_duration 5658.; String time_coverage_end "2018-10-14T01:38:05.000000Z"; String time_coverage_start "2018-10-14T00:03:47.000000Z"; Float64 geospatial_lat_min 68.916474823665695; Float64 geospatial_lon_min 63.30432580191718; Float64 geospatial_lat_max 88.043374802950964; Float64 geospatial_lon_max -136.62047583959989; String publisher_name "NSIDC DAAC > NASA National Snow and Ice Data Center Distributed Active Archive Center"; String publisher_email "nsidc@nsidc.org"; String publisher_url "http://nsidc.org/daac/"; String identifier_product_type "ATL07"; String identifier_product_doi "doi:10.5067/ATLAS/ATL07.003"; String institution "National Aeronautics and Space Administration (NASA)"; String creator_name "GSFC I-SIPS > ICESat-2 Science Investigator-led Processing System"; String summary "The purpose of ATL07 is to provide along-track sea ice heights and associated statistics."; String keywords "EARTH SCIENCE > SPECTRAL/ENGINEERING > LIDAR > LIDAR BACKSCATTER > NONE > NONE > NONE"; String keywords_vocabulary "NASA/GCMD Science Keywords"; 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."; String processing_level "2A"; String references "http://nsidc.org/data/icesat2/data.html"; String project "ICESat-2 > Ice, Cloud, and land Elevation Satellite-2"; String instrument "ATLAS > Advanced Topographic Laser Altimeter System"; String platform "ICESat-2 > Ice, Cloud, and land Elevation Satellite-2"; String source "Spacecraft"; } /orbit_info/ { String HDF5_OBJ_FULLPATH "/orbit_info/"; String Description "Contains orbit information."; String data_rate "Varies. Data are only provided when one of the stored values (besides time) changes."; } /orbit_info/crossing_time { String HDF5_OBJ_FULLPATH "/orbit_info/crossing_time"; String CLASS "DIMENSION_SCALE"; String NAME "crossing_time"; String contentType "referenceInformation"; 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."; String long_name "Ascending Node Crossing Time"; String source "POD/PPD"; String standard_name "time"; String units "seconds since 2018-01-01"; } /orbit_info/cycle_number { String HDF5_OBJ_FULLPATH "/orbit_info/cycle_number"; String contentType "referenceInformation"; String coordinates "crossing_time"; String description "A count of the number of exact repeats of this reference orbit."; String long_name "Cycle Number"; String source "Operations"; String units "1"; Int16 valid_max 50; Int16 valid_min 0; } /orbit_info/orbit_number { String HDF5_OBJ_FULLPATH "/orbit_info/orbit_number"; String contentType "referenceInformation"; String coordinates "crossing_time"; String description "Unique identifying number for each planned ICESat-2 orbit."; String long_name "Orbit Number"; String source "Operations"; String units "1"; UInt16 valid_max 65000; UInt16 valid_min 1; } /orbit_info/rgt { String HDF5_OBJ_FULLPATH "/orbit_info/rgt"; String contentType "referenceInformation"; String coordinates "crossing_time"; 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."; String long_name "Reference Ground track"; String source "POD/PPD"; String units "1"; Int16 valid_max 1387; Int16 valid_min 1; } /orbit_info/sc_orient { String HDF5_OBJ_FULLPATH "/orbit_info/sc_orient"; String contentType "referenceInformation"; String coordinates "sc_orient_time"; 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."; String flag_meanings "backward forward transition"; Int16 flag_values 0, 1, 2; String long_name "Spacecraft Orientation"; String source "POD/PPD"; String units "1"; Int16 valid_max 2; Int16 valid_min 0; } /orbit_info/sc_orient_time { String HDF5_OBJ_FULLPATH "/orbit_info/sc_orient_time"; String CLASS "DIMENSION_SCALE"; String NAME "sc_orient_time"; String contentType "referenceInformation"; 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."; String long_name "Time of Last Spacecraft Orientation Change"; String source "POD/PPD"; String standard_name "time"; String units "seconds since 2018-01-01"; } /orbit_info/lan { String HDF5_OBJ_FULLPATH "/orbit_info/lan"; String contentType "referenceInformation"; String coordinates "crossing_time"; String description "Longitude at the ascending node crossing."; String long_name "Ascending Node Longitude"; String source "POD/PPD"; String units "degrees_east"; Float64 valid_max 180.; Float64 valid_min -180.; } /METADATA/ { String HDF5_OBJ_FULLPATH "/METADATA/"; String Description "ISO19115 Structured Metadata Represented within HDF5"; String iso_19139_dataset_xml " ATL07-01_20181014000347_02350101_003_02.h5 NSIDC DAAC > National Snow and Ice Data Center DAAC nsidc@nsidc.org http://nsidc.org/daac/ pointOfContact 2020-05-29T14:35:54.000000Z ISO 19115-2 Geographic information - Metadata - Part 2: Extensions for imagery and gridded data ISO 19115-2:2009-02-15 ATL07-01_20181014000347_02350101_003_02.h5 2020-05-29T14:35:54.000000Z creation ATL07 The ECS Short Name 003 The ECS Version ID ATL07-01_20181014000347_02350101_003_02.h5 ProducerGranuleId 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. onGoing ATL07 003 largerWorkCitation eng geoscientificInformation AscendingCrossing: -127.04822056072560 StartLatitude: 27.000000000000000 StartDirection:A EndLatitude: 27.000000000000000 EndDirection: D gov.nasa.esdis.umm.orbitparameters OrbitParameters OrbitNumber: 436 EquatorCrossingLongitude: -127.04822056072560 EquatorCrossingDateTime: 2018-10-14T00:03:47.381163Z gov.nasa.esdis.umm.orbitcalculatedspatialdomains OrbitCalculatedSpatialDomains 2018-10-14T00:21:48.398512Z 2018-10-14T00:29:02.217009Z dataset 2020-05-29T14:35:54.000000Z;2bed11f8-37e3-3547-bf60-9d7af1919f0d;Created by PGE atlas_l3a_si Version 4.3.2 2020-05-29T14:35:54.000000Z "; String iso_19139_series_xml " ATL07.003 eng utf8 series NSIDC DAAC > NASA National Snow and Ice Data Center Distributed Active Archive Center 303-492-6199 303-492-2468 1540 30th St Campus Box 449 Boulder Colorado 80309-0449 USA nsidc@nsidc.org http://nsidc.org/daac/ 9:00 A.M. to 5:00 P.M., U.S. Mountain Time, Monday through Friday, excluding U.S. holidays. Contact by e-mail first pointOfContact 2015-10-15 ISO 19115-2 Geographic information - Metadata - Part 2: Extensions for imagery and gridded data ISO 19115-2:2009(E) ATLAS/ICESat-2 L2A Normalized Relative Backscatter Profiles 2016-06-09 revision 003 ATL07 The ECS Short Name 003 The ECS Version ID doi:10.5067/ATLAS/ATL07.003 gov.nasa.esdis A Digital Object Identifier (DOI) National Aeronautics and Space Administration (NASA) resourceProvider GSFC I-SIPS > ICESat-2 Science Investigator-led Processing System originator Initial version of the processing software 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. The purpose of ATL07 is to provide along-track sea ice heights and associated statistics. 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. onGoing NSIDC DAAC > NASA National Snow and Ice Data Center Distributed Active Archive Center distributor HDF 5 EARTH SCIENCE > SPECTRAL/ENGINEERING > LIDAR > LIDAR BACKSCATTER > NONE > NONE > NONE theme NASA/GCMD Science Keywords NASA Global Change Master Directory (GCMD) User Support Office NASA Global Change Master Directory, Goddard Space Flight Center Greenbelt MD 20771 USA gcmduso@gcmd.gsfc.nasa.gov http://gcmd.nasa.gov/ http web browser NASA Global Change Master Directory (GCMD) Home Page information http://gcmd.nasa.gov/MailComments/MailComments.jsf?rcpt=gcmduso custodian Global Change Master Directory (GCMD) NASA Global Change Master Directory, Goddard Space Flight Center Greenbelt MD 20771 USA gcmduso@gcmd.gsfc.nasa.gov http://gcmd.nasa.gov/Resources/valids/ http web browser NASA Global Change Master Directory (GCMD) Keyword Page This page describes the NASA GCMD Keywords, how to reference those keywords and provides download instructions. download http://gcmd.nasa.gov/MailComments/MailComments.jsf?rcpt=gcmduso custodian GEOGRAPHIC REGION > GLOBAL place NASA/GCMD Location Keywords NASA/NSIDC_DAAC > NASA National Snow and Ice Data Center Distributed Active Archive Center dataCenter NASA/GCMD Data Center Keywords Earth Observation Satellites > NASA Decadal Survey > ICESAT-2 > Ice, Cloud, and land Elevation Satellite-2 platform NASA/GCMD Platform Keywords Earth Remote Sensing Instruments > Active Remote Sensing > Altimeters > Lidar/Laser Altimeters > ATLAS > Advanced Topographic Laser Altimeter System instrument NASA/GCMD Instrument Keywords 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. eng geoscientificInformation SpatialCoverageType=HORIZONTAL, SpatialGranuleSpatialRepresentation=ORBIT, TemporalRangeType=Continuous Range, TimeType=UTC -180.0 180.0 -90.0 90.0 SwathWidth: 36.0 Period: 96.8 InclinationAngle: 92.0 NumberOfOrbits: 1.0 StartCircularLatitude: 0.0 gov.nasa.esdis.umm.orbitparameters OrbitParameters 2005-01-01T00:00:00Z 2020-12-31T23:59:59Z 2A 2A HDF 5 NSIDC DAAC > NASA National Snow and Ice Data Center Distributed Active Archive Center distributor http://nsidc.org/data/icesat2/data.html http Data Product Description Page information http://nsidc.org/data/icesat2/order.html http Data Product Order Page order https://doi.org/10.5067/ATLAS/ATL07.003 http Digital Object Identifier URL information ATLAS > Advanced Topographic Laser Altimeter System ATLAS Advanced Topographic Laser Altimeter System Laser Altimeter 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. ICESat-2 > Ice, Cloud, and land Elevation Satellite-2 ICESat-2 > Ice, Cloud, and land Elevation Satellite-2 ICESat-2 Ice, Cloud, and land Elevation Satellite-2 underDevelopment ICESat-2 > Ice, Cloud, and land Elevation Satellite-2 ICESat-2 Ice, Cloud, and land Elevation Satellite-2 Spacecraft "; } /METADATA/AcquisitionInformation/ { String HDF5_OBJ_FULLPATH "/METADATA/AcquisitionInformation/"; } /METADATA/AcquisitionInformation/lidar/ { String HDF5_OBJ_FULLPATH "/METADATA/AcquisitionInformation/lidar/"; String pulse_rate "10000 pps"; String wavelength "532 nm"; String identifier "ATLAS"; String type "Laser Altimeter"; 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."; } /METADATA/AcquisitionInformation/lidarDocument/ { String HDF5_OBJ_FULLPATH "/METADATA/AcquisitionInformation/lidarDocument/"; String edition "Pre-Release"; String publicationDate "12/31/17"; String title "A document describing the ATLAS instrument will be provided by the ICESat-2 Project Science Office."; } /METADATA/AcquisitionInformation/platform/ { String HDF5_OBJ_FULLPATH "/METADATA/AcquisitionInformation/platform/"; String identifier "ICESat-2"; String description "Ice, Cloud, and land Elevation Satellite-2"; String type "Spacecraft"; } /METADATA/AcquisitionInformation/platformDocument/ { String HDF5_OBJ_FULLPATH "/METADATA/AcquisitionInformation/platformDocument/"; String edition "31-Dec-16"; String publicationDate "31-Dec-16"; 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"; } /METADATA/DataQuality/ { String HDF5_OBJ_FULLPATH "/METADATA/DataQuality/"; String scope "NOT_SET"; } /METADATA/DataQuality/CompletenessOmission/ { String HDF5_OBJ_FULLPATH "/METADATA/DataQuality/CompletenessOmission/"; String evaluationMethodType "directInternal"; String measureDescription "TBD"; String nameOfMeasure "TBD"; String unitofMeasure "TBD"; String value "NOT_SET"; } /METADATA/DataQuality/DomainConsistency/ { String HDF5_OBJ_FULLPATH "/METADATA/DataQuality/DomainConsistency/"; String evaluationMethodType "directInternal"; String measureDescription "TBD"; String nameOfMeasure "TBD"; String unitofMeasure "TBD"; String value "NOT_SET"; } /METADATA/ProductSpecificationDocument/ { String HDF5_OBJ_FULLPATH "/METADATA/ProductSpecificationDocument/"; String ShortName "ATL07_SDP"; String characterSet "utf8"; String edition "v4.3"; String language "eng"; String publicationDate "Feb 2020"; String title "ICESat-2-SIPS-SPEC-4261 - ATLAS Science Algorithm Standard Data Product (SDP) Volume 6 (ATL07)."; } /METADATA/SeriesIdentification/ { String HDF5_OBJ_FULLPATH "/METADATA/SeriesIdentification/"; String maintenanceAndUpdateFrequency "asNeeded"; String maintenanceDate "SET_BY_META"; String VersionID "003"; String language "eng"; String characterSet "utf8"; String pointOfContact "NSIDC DAAC > NASA National Snow and Ice Data Center Distributed Active Archive Center"; String longName "ATLAS/ICESat-2 L2A Normalized Relative Backscatter Profiles"; String shortName "ATL07"; String identifier_product_DOI "doi:10.5067/ATLAS/ATL07.003"; String revisionDate "2016-06-09"; String resourceProviderOrganizationName "National Aeronautics and Space Administration (NASA)"; 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."; String purpose "The purpose of ATL07 is to provide along-track sea ice heights and associated statistics."; 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."; String status "onGoing"; String format "HDF"; String formatVersion "5"; String topicCategory "geoscientificInformation"; String mission "ICESat-2 > Ice, Cloud, and land Elevation Satellite-2"; } /METADATA/DatasetIdentification/ { String HDF5_OBJ_FULLPATH "/METADATA/DatasetIdentification/"; String spatialRepresentationType "along-track"; String creationDate "2020-05-29T14:35:54.000000Z"; String uuid "2bed11f8-37e3-3547-bf60-9d7af1919f0d"; String fileName "ATL07-01_20181014000347_02350101_003_02.h5"; String VersionID "003"; String language "eng"; String characterSet "utf8"; String shortName "ATL07"; String originatorOrganizationName "GSFC I-SIPS > ICESat-2 Science Investigator-led Processing System"; 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."; String purpose "The purpose of ATL07 is to provide along-track sea ice heights and associated statistics."; 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."; String status "onGoing"; String topicCategory "geoscientificInformation"; } /METADATA/Extent/ { String HDF5_OBJ_FULLPATH "/METADATA/Extent/"; Float64 northBoundLatitude 88.043374802950964; Float64 eastBoundLongitude -136.62047583959989; Float64 southBoundLatitude 68.916474823665695; Float64 westBoundLongitude 63.30432580191718; String rangeBeginningDateTime "2018-10-14T00:21:48.398512Z"; String rangeEndingDateTime "2018-10-14T00:29:02.217009Z"; } /METADATA/QADatasetIdentification/ { String HDF5_OBJ_FULLPATH "/METADATA/QADatasetIdentification/"; String abstract "An ASCII product that contains statistical information on data product results. These statistics enable data producers and users to assess the quality of the data in the data product granule"; String creationDate "2020-05-29T17:45:40.000000Z"; String fileName "ATL07-01_20181014000347_02350101_003_02.qa"; } /METADATA/Lineage/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/"; } /METADATA/Lineage/ANC38-07/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC38-07/"; String description "ISO 19139 XML file containing DataSet-level metadata information."; String fileName "ANC38-07_20200311164501_003_01.xml"; String shortName "ANC38-07"; String uuid "4f41aebb-fa0d-378a-b628-0532fe8b6a67"; String version "003"; } /METADATA/Lineage/Control/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/Control/"; String 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."; String fileName "CTL_atlas_l3a_si_004157211.ctl"; String shortName "CNTL"; String version "1"; } /METADATA/Lineage/ANC02-02/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC02-02/"; String 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"; String fileName "htcorr_2gauss_convolve.dat"; String shortName "ANC02-02"; String uuid "d1568221-bfd4-3e58-90ef-a212c3297d17"; String version "001"; } /METADATA/Lineage/ANC25-07/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC25-07/"; String description "HDF5 template file that defines the organization and default content of the product."; String fileName "ANC25-07_20200311165637_043_01.h5"; String shortName "ANC25-07"; String uuid "27cc9374-7a28-3d87-93b5-5c8aa490f471"; String version "043"; } /METADATA/Lineage/ANC15/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC15/"; String description "Mean Dynamic Ocean Topography file provided by Sea Ice ATBD lead."; String fileName "mss_arctic_20190715.2.5km"; String shortName "ANC15"; String uuid "011eeff8-50fd-36bf-8de1-36d86990b5e6"; String version "20190715"; } /METADATA/Lineage/ANC26-07/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC26-07/"; String description "HDF5 template file that defines the organization and default content of the product metadata."; String fileName "ANC26-07_20200311165645_043_01.h5"; String shortName "ANC26-07"; String uuid "3140c36b-6508-3ff0-b8f9-b605459c87ba"; String version "043"; } /METADATA/Lineage/ANC36-07/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC36-07/"; String description "ISO 19139 XML file containing Series-level metadata information."; String fileName "ANC36-07_20200311164459_003_01.xml"; String shortName "ANC36-07"; String uuid "72e6a080-17e9-3fcf-8a25-b1d9a9fe8fa1"; String version "003"; } /METADATA/Lineage/ATL03/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ATL03/"; String description "ICESat-2 ATLAS L2A Global Geolocated Photon data products."; 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"; String shortName "ATL03", "ATL03", "ATL03", "ATL03"; String uuid "b611ccb1-aa66-327a-b9cc-8c234051dd4c", "1a9bd4ee-b9b2-3b47-9614-d8e214e18fe1", "6424759e-1924-37bf-8def-9c00e78de775", "807bef11-720f-376b-9905-2b3f947fa7bf"; String version "003", "003", "003", "003"; Int32 start_cycle 1, 1, 1, 1; Int32 end_cycle 1, 1, 1, 1; Int32 start_orbit 436, 436, 436, 436; Int32 end_orbit 436, 436, 436, 436; Int32 start_rgt 235, 235, 235, 235; Int32 end_rgt 235, 235, 235, 235; Int32 start_region 2, 3, 4, 5; Int32 end_region 2, 3, 4, 5; Int32 start_geoseg 149697, 330711, 446036, 555725; Int32 end_geoseg 330710, 446035, 555724, 671052; } /METADATA/Lineage/ATL09/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ATL09/"; String description "ICESat-2 ATLAS L3A atmosphere data products."; String fileName "ATL09_20181014000347_02350101_003_01.h5"; String shortName "ATL09"; String uuid "5eed3d7d-4915-3233-9a69-2998067566d9"; String version "003"; Int32 start_cycle 1; Int32 end_cycle 1; Int32 start_orbit 436; Int32 end_orbit 436; Int32 start_rgt 235; Int32 end_rgt 235; Int32 start_region 1; Int32 end_region 14; Int32 start_geoseg 11; Int32 end_geoseg 2007120; } /METADATA/Lineage/ANC31/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC31/"; String description "Sea Ice Concentration file"; String fileName "seaice_conc_daily_icdr_nh_f18_20181014_v01r00.nc"; String shortName "ANC31"; String uuid "5bcdc4d3-8815-344d-939a-2e50a56c09a9"; String version "nc"; } /METADATA/Lineage/ANC19/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC19/"; String description "TAI to UTC leapsecond file retrieved from ftp://maia.usno.navy.mil/ser7/tai-utc.dat"; String fileName "tai_utc_2017.dat"; String shortName "ANC19"; String uuid "7c66d365-278a-31f7-8fe4-9c80e2f012e5"; String version "001"; } /METADATA/ProcessStep/ { String HDF5_OBJ_FULLPATH "/METADATA/ProcessStep/"; } /METADATA/ProcessStep/Browse/ { String HDF5_OBJ_FULLPATH "/METADATA/ProcessStep/Browse/"; String 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."; String identifier "atlas_brw"; String softwareVersion "Version 2.3"; String softwareDate "Feb 14 2020"; String softwareTitle "Creates ATLAS HDF5 browse files"; String runTimeParameters "CTL_atlas_l3a_si_004157211.ctl"; String stepDateTime "2020-05-29T17:45:54.000000Z"; } /METADATA/ProcessStep/Metadata/ { String HDF5_OBJ_FULLPATH "/METADATA/ProcessStep/Metadata/"; String 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."; String identifier "atlas_meta"; String softwareVersion "Version 4.3"; String softwareDate "Feb 3 2020"; String softwareTitle "Creates ATLAS XML metadata files"; String runTimeParameters "CTL_atlas_l3a_si_004157211.ctl"; String stepDateTime "2020-05-29T17:47:04.000000Z"; } /METADATA/ProcessStep/PGE/ { String HDF5_OBJ_FULLPATH "/METADATA/ProcessStep/PGE/"; String ATBDDate "12/04/2019"; String ATBDTitle "Algorithm Theoretical Basis Document (ATBD) For Sea Ice Products"; String ATBDVersion "N/A"; String documentDate "Feb 2020"; String documentation "ATLAS Science Algorithm Software Design Description (SDD) - Volume 10 (atlas_l3a_si)"; 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."; String identifier "atlas_l3a_si"; String softwareVersion "Version 4.3.2"; String softwareDate "May 22 2020"; String softwareTitle "ASAS L3A Sea Ice PGE"; String runTimeParameters "CTL_atlas_l3a_si_004157211.ctl"; String stepDateTime "2020-05-29T14:35:54.000000Z"; } /METADATA/ProcessStep/QA/ { String HDF5_OBJ_FULLPATH "/METADATA/ProcessStep/QA/"; String 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"; String identifier "atl07_qa_util"; String softwareVersion "Version 4.3"; String softwareDate "Feb 3 2020"; String softwareTitle "ATL07 QA Utility"; String runTimeParameters "CTL_atlas_l3a_si_004157211.ctl"; String stepDateTime "2020-05-29T17:45:40.000000Z"; } /gt1r/ { String HDF5_OBJ_FULLPATH "/gt1r/"; String Description "This ground contains parameters and subgroups related a specific groundtrack."; String data_rate "Each subgroup identifies its particular data rate."; String atlas_pce "pce3"; String atlas_beam_type "strong"; String groundtrack_id "gt1r"; String atmosphere_profile "profile_1"; String atlas_spot_number "5"; String sc_orientation "Forward"; } /gt1r/sea_ice_segments/ { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/"; String Description "Top group for sea ice segments as computed by the ATBD aglorithm"; String data_rate "Data within this group are stored at the variable segment rate."; } /gt1r/sea_ice_segments/heights/ { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/heights/"; String 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."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt1r/sea_ice_segments/heights/height_segment_fit_quality_flag { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/heights/height_segment_fit_quality_flag"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String flag_meanings "invalid best high med low poor"; Int16 flag_values -1, 1, 2, 3, 4, 5; String long_name "height Quality Flag"; String source "ATBD, section 4.2.4.2"; String units "1"; Int16 valid_max 5; Int16 valid_min -1; } /gt1r/sea_ice_segments/heights/height_segment_length_seg { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/heights/height_segment_length_seg"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "along-track length of segment containing n_photons_actual"; String long_name "length of segment"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1r/sea_ice_segments/heights/height_segment_asr_calc { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/heights/height_segment_asr_calc"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Computed apparent surface reflectance for the sea ice segment."; String long_name "Calculated Apparent Surface Reflectivity"; String source "Sea Ice ATBD"; String units "1"; } /gt1r/sea_ice_segments/heights/height_segment_quality { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/heights/height_segment_quality"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Height segment quality flag, 1 is good quality, 0 is bad depending on fit, wguassian, or layer flag"; String flag_meanings "bad_quality good_quality"; Int16 flag_values 0, 1; String long_name "Height Segment Quality Flag"; String source "ATBD, section 4.2.4"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt1r/sea_ice_segments/heights/height_segment_n_pulse_seg { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/heights/height_segment_n_pulse_seg"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "number of laser pulses"; String long_name "number of laser pulses"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt1r/sea_ice_segments/heights/across_track_distance { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/heights/across_track_distance"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Across track distance of photons averaged over the sea ice height segment."; String long_name "Across Track Distance"; String source "ATBD, section 4.2.4"; String units "meters"; } /gt1r/sea_ice_segments/heights/height_segment_htcorr_skew { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/heights/height_segment_htcorr_skew"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "height corection for skew"; String long_name "Height Correction for Skew"; String source "ATBD, section 4.2.6"; String units "meters"; } /gt1r/sea_ice_segments/heights/height_segment_ssh_flag { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/heights/height_segment_ssh_flag"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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"; String flag_meanings "sea_ice sea_surface"; Int16 flag_values 0, 1; String long_name "Sea Surface Flag"; String source "ATBD, section 4.3"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt1r/sea_ice_segments/heights/height_segment_height { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/heights/height_segment_height"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean height from along-track segment fit detremined by the sea ice algorithm"; String long_name "height of segment surface"; String source "ATBD, section 4.2.2.4"; String units "meters"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; } /gt1r/sea_ice_segments/heights/height_segment_type { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/heights/height_segment_type"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Value that indicates segment surface type as sea ice or different types of sea surface. 0=cloud covered: rsurf"; 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"; Int16 flag_values 0, 1, 2, 3, 4, 5, 6, 7, 8, 9; String long_name "Segment surface type"; String source "ATBD, section 4.3"; String units "1"; Int16 valid_max 9; Int16 valid_min 0; } /gt1r/sea_ice_segments/heights/height_segment_confidence { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/heights/height_segment_confidence"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Confidence level in the surface height estimate based on the number of photons; the background noise rate; and the error analysis"; String long_name "Surface height confidence"; String source "ATBD, section 4.2.4.2"; String units "1"; } /gt1r/sea_ice_segments/heights/height_segment_surface_error_est { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/heights/height_segment_surface_error_est"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Error estimate of the surface height"; String long_name "h surface error est"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1r/sea_ice_segments/heights/height_segment_w_gaussian { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/heights/height_segment_w_gaussian"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "width of best fit gaussian"; String long_name "width of best fit gaussian"; String source "ATBD, section 4.2.4"; String units "meters"; } /gt1r/sea_ice_segments/heights/height_segment_rms { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/heights/height_segment_rms"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "RMS difference between sea ice modeled and observed photon height distribution"; String long_name "height rms"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1r/sea_ice_segments/height_segment_id { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/height_segment_id"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Identifier of each height segment"; String long_name "Identifier of each height segment"; String source "ATBD, section 5.2"; String units "1"; } /gt1r/sea_ice_segments/seg_dist_x { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/seg_dist_x"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Along-track distance from the equator crossing to the segment center."; String long_name "Along track distance"; String source "Sea Ice ATBD"; String units "meters"; } /gt1r/sea_ice_segments/longitude { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/longitude"; String contentType "referenceInformation"; String coordinates "delta_time latitude"; String description "Longitude, WGS84, East=+,Lon of segment center"; String long_name "Longitude"; String source "ATBD, section 4.4"; String standard_name "longitude"; String units "degrees_east"; Float64 valid_max 180.; Float64 valid_min -180.; } /gt1r/sea_ice_segments/latitude { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/latitude"; String contentType "referenceInformation"; String coordinates "delta_time longitude"; String description "Latitude, WGS84, North=+, Lat of segment center"; String long_name "Latitude"; String source "ATBD, section 4.4"; String standard_name "latitude"; String units "degrees_north"; Float64 valid_max 90.; Float64 valid_min -90.; } /gt1r/sea_ice_segments/geophysical/ { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geophysical/"; String Description "Contains geophysical parameters and corrections used to correct photon heights for geophysical effects, such as tides."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt1r/sea_ice_segments/geophysical/height_segment_t2m { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geophysical/height_segment_t2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Temperature at 2m above the displacement height (K)"; String long_name "temperature_at_2m"; String source "ATL09"; String standard_name "temperature"; String units "K"; } /gt1r/sea_ice_segments/geophysical/height_segment_dac { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geophysical/height_segment_dac"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect."; String long_name "Dynamic Atmosphere Correction"; String source "Sea Ice ATBD"; String units "meters"; } /gt1r/sea_ice_segments/geophysical/height_segment_ps { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geophysical/height_segment_ps"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Sea Level Pressure (Pa)"; String long_name "sea level pressure"; String source "ATL09"; String standard_name "pressure"; String units "Pa"; } /gt1r/sea_ice_segments/geophysical/height_segment_ib { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geophysical/height_segment_ib"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Inverted barometer effect calculated from surface pressure"; String long_name "Inverted barometer effect"; String source "ATBD, section 4.2"; String units "meters"; } /gt1r/sea_ice_segments/geophysical/height_segment_load { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geophysical/height_segment_load"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Load Tide - Local displacement due to Ocean Loading (-6 to 0 cm)."; String long_name "Load Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt1r/sea_ice_segments/geophysical/height_segment_geoid { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geophysical/height_segment_geoid"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Geoid height above WGS-84 reference ellipsoid (range -107 to 86m), based on the EGM2008 model."; String long_name "EGM2008 Geoid"; String source "Sea Ice ATBD"; String units "meters"; } /gt1r/sea_ice_segments/geophysical/height_segment_ocean { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geophysical/height_segment_ocean"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Ocean Tides including diurnal and semi-diurnal (harmonic analysis), and longer period tides (dynamic and self-consistent equilibrium)"; String long_name "Ocean Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt1r/sea_ice_segments/geophysical/height_segment_v2m { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geophysical/height_segment_v2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Northward wind at 2m above the displacement height (m/s-1)"; String long_name "Northward_wind_at_2m"; String source "ATL09"; String standard_name "northward_wind"; String units "m s-1"; } /gt1r/sea_ice_segments/geophysical/height_segment_mss { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geophysical/height_segment_mss"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean sea surface height above WGS-84 reference ellipsoid (range: -105 to 87m), based on the DTU13 model."; String long_name "DTU13 Mean Sea Surface"; String source "Sea Ice ATBD"; String units "meters"; } /gt1r/sea_ice_segments/geophysical/height_segment_u2m { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geophysical/height_segment_u2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Eastward wind at 2m above the displacement height (m/s-1)"; String long_name "Eastward_wind_at_2m"; String source "ATL09"; String standard_name "eastward_wind"; String units "m s-1"; } /gt1r/sea_ice_segments/geophysical/height_segment_lpe { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geophysical/height_segment_lpe"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Long period equilibrium tide self-consistent with ocean tide model (+-0.04m). (dependent only on time and latitude)"; String long_name "Equilibrium Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt1r/sea_ice_segments/geophysical/height_segment_earth { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geophysical/height_segment_earth"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Solid Earth Tide"; String long_name "Earth Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt1r/sea_ice_segments/geophysical/height_segment_pole { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geophysical/height_segment_pole"; String coordinates "../delta_time ../latitude ../longitude"; String description "Pole Tide -Rotational deformation due to polar motion (-1.5 to 1.5 cm)."; String long_name "Pole Tide"; String source "Sea Ice ATBD"; String units "meters"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; } /gt1r/sea_ice_segments/geoseg_beg { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geoseg_beg"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Geolocation segment (geoseg) ID associated with the first photon used in this sea ice segment"; String long_name "Beginning GEOSEG"; String source "Sea Ice ATBD"; String units "1"; } /gt1r/sea_ice_segments/delta_time { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/delta_time"; String contentType "physicalMeasurement"; String coordinates "latitude longitude"; 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."; String long_name "Elapsed GPS seconds"; String source "telemetry"; String standard_name "time"; String units "seconds since 2018-01-01"; String CLASS "DIMENSION_SCALE"; String NAME "gt1r/sea_ice_segments/delta_time"; } /gt1r/sea_ice_segments/stats/ { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/"; String Description "Contains parameters related to quality and corrections on the sea ice height paramters"; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt1r/sea_ice_segments/stats/msw_flag { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/msw_flag"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; 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."; 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"; Int16 flag_values -1, 0, 1, 2, 3, 4, 5; String long_name "Multiple Scattering Warning Flag"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 5; Int16 valid_min -1; } /gt1r/sea_ice_segments/stats/hist_median_h { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/hist_median_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Median of the n_fit_photons heights"; String long_name "trimmed photon heights median"; String source "ATBD, section 4.2.3.1"; String units "meters"; } /gt1r/sea_ice_segments/stats/height_filter_min { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/height_filter_min"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height minimum used in the ssh height filter"; String long_name "Height Filter Min"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt1r/sea_ice_segments/stats/cloud_flag_atm { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/cloud_flag_atm"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of layers found from the backscatter profile using the DDA layer finder."; String long_name "Cloud Flag Atm"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 10; Int16 valid_min 0; } /gt1r/sea_ice_segments/stats/fpb_avg_dt { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/fpb_avg_dt"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction average dead time"; String long_name "fpb correction average deadtime"; String source "Sea Ice ATBD"; String units "ns"; } /gt1r/sea_ice_segments/stats/ds_si_hist_bins { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/ds_si_hist_bins"; String CLASS "DIMENSION_SCALE"; String NAME "ds_si_hist_bins"; String contentType "auxiliaryInformation"; 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."; String long_name "Sea Ice Histogram Bins Dimension Scale"; String source "SeaIce ATBD"; String units "1"; } /gt1r/sea_ice_segments/stats/fpb_strength { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/fpb_strength"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction strength"; String long_name "fpb correction strength"; String source "Sea Ice ATBD"; String units "photons/shot"; } /gt1r/sea_ice_segments/stats/bsnow_con { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/bsnow_con"; Int16 _FillValue 127; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Blowing snow confidence"; String long_name "Blowing snow confidence"; String source "ATL09"; String units "1"; } /gt1r/sea_ice_segments/stats/layer_flag { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/layer_flag"; String contentType "qualityInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String flag_meanings "likely_clear likely_cloudy"; Int16 flag_values 0, 1; String long_name "Consolidated cloud flag"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt1r/sea_ice_segments/stats/hist_photon_bin_size { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/hist_photon_bin_size"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "bin size of photon height histogram"; String long_name "height histogram bin size"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1r/sea_ice_segments/stats/backgr_calc { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/backgr_calc"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Calculated background count rate based on sun angle, surface slope, unit reflectance"; String long_name "background count rate calculated"; String source "ATBD, section 4.2.3"; String units "hz"; } /gt1r/sea_ice_segments/stats/fpb_corr { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/fpb_corr"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated first-photon bias(fpb) correction to mean segment height"; String long_name "first photon bias correction"; String source "Sea Ice ATBD"; String units "meters"; } /gt1r/sea_ice_segments/stats/bsnow_h { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/bsnow_h"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Blowing snow layer top height"; String long_name "Blowing snow top h"; String source "ATL09"; String units "meters"; } /gt1r/sea_ice_segments/stats/hist_photon_bottom { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/hist_photon_bottom"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "lower bound of height histogram"; String long_name "height histogram minimum"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1r/sea_ice_segments/stats/background_r_norm { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/background_r_norm"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background rate normalized to a fixed solar elevation angle"; String long_name "Normalized background (50-shot)"; String source "ATBD section 4.3.1.3"; String units "hz"; } /gt1r/sea_ice_segments/stats/exmax_mean_2 { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/exmax_mean_2"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mean 2"; String long_name "Exmax Mean 2"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt1r/sea_ice_segments/stats/background_int_height { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/background_int_height"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "The height of the altimetric range window after subtracting the height span of the signal photon events in the 50-shot span"; String long_name "Height of column used in background calculation"; String source "ATBD, section 7.3"; String units "meters"; } /gt1r/sea_ice_segments/stats/n_photons_actual { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/n_photons_actual"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons gathered"; String long_name "Number of photons found for the segment"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt1r/sea_ice_segments/stats/ice_conc { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/ice_conc"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "sea ice concentration"; String long_name "sea ice concentration"; String source "ATBD, section 3.1.4"; String units "1"; } /gt1r/sea_ice_segments/stats/exmax_stdev_2 { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/exmax_stdev_2"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height standard deviation 2"; String long_name "Exmax Stdev 2"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt1r/sea_ice_segments/stats/cloud_flag_asr { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/cloud_flag_asr"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; 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"; 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"; Int16 flag_values 0, 1, 2, 3, 4, 5, 6; String long_name "Cloud Flag ASR"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 6; Int16 valid_min 0; } /gt1r/sea_ice_segments/stats/exmax_stdev_1 { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/exmax_stdev_1"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height standard deviation 1"; String long_name "Exmax Stdev 1"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt1r/sea_ice_segments/stats/fpb_corr_width { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/fpb_corr_width"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction width"; String long_name "fpb correction width"; String source "Sea Ice ATBD"; String units "ns"; } /gt1r/sea_ice_segments/stats/height_coarse_stdev { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/height_coarse_stdev"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height standard deviation of coarse tracker"; String long_name "Coarse Height Sdev"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt1r/sea_ice_segments/stats/height_filter_05 { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/height_filter_05"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height fifth percentile used in the ssh height filter"; String long_name "Height Filter 5th Percentile"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt1r/sea_ice_segments/stats/n_photons_used { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/n_photons_used"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons in the trimmed histogram."; String long_name "Number of photons used for fit"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt1r/sea_ice_segments/stats/backgr_r_200 { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/backgr_r_200"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background count rate, averaged over the segment based on ATLAS 50 pulse counts"; String long_name "Background rate 200 hz"; String source "ATL09"; String units "hz"; } /gt1r/sea_ice_segments/stats/hist_photon_top { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/hist_photon_top"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "upper bound of height histogram"; String long_name "height histogram maximum"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1r/sea_ice_segments/stats/hist_w { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/hist_w"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Segment histogram width estimate"; String long_name "Segment histogram width estimate"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1r/sea_ice_segments/stats/hist_mean_h { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/hist_mean_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean of the n_fit_photons heights"; String long_name "photon heights mean"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1r/sea_ice_segments/stats/height_coarse_mn { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/height_coarse_mn"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height mean of coarse tracker"; String long_name "Coarse Track Height Mean"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt1r/sea_ice_segments/stats/exmax_mean_1 { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/exmax_mean_1"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mean 1"; String long_name "Exmax Mean 1"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt1r/sea_ice_segments/stats/hist_photon_heights { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/hist_photon_heights"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Histogram of the n_fit_photons heights"; String long_name "photon heights histogram"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt1r/sea_ice_segments/stats/trim_height_top { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/trim_height_top"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "maximum height of trimmed photons used in the surface calculation procedure"; String long_name "maximum height of trimmed photons"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1r/sea_ice_segments/stats/exmax_mix { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/exmax_mix"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mix ratio"; String long_name "Exmax Mix"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt1r/sea_ice_segments/stats/asr_25 { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/asr_25"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Apparent surface reflectance at 25 hz, averaged to the sea ice segment."; String long_name "Apparent Surface Reflectance 25hz"; String source "Sea Ice ATBD"; String units "1"; } /gt1r/sea_ice_segments/stats/photon_rate { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/photon_rate"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "photon count rate, averaged over segment"; String long_name "photon rate"; String source "ATBD, section 4.2.2.4"; String units "photons/shot"; } /gt1r/sea_ice_segments/stats/trim_height_bottom { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/trim_height_bottom"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "minimum height of trimmed photons used in the surface calculation procedure"; String long_name "minimum height of trimmed photons"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1r/sea_ice_segments/stats/n_photons_define { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/n_photons_define"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons to gather."; String long_name "Number of photons defining the segment"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt1r/sea_ice_segments/stats/backgr_r_25 { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/stats/backgr_r_25"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background count rate, averaged over the segment based on 25 hz atmosphere"; String long_name "Background rate 25hz"; String source "ATL09"; String units "hz"; } /gt1r/sea_ice_segments/geoseg_end { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geoseg_end"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Geolocation segment (geoseg) ID associated with the last photon used in this sea ice segment"; String long_name "Ending GEOSEG"; String source "Sea Ice ATBD"; String units "1"; } /gt1r/sea_ice_segments/geolocation/ { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geolocation/"; String Description "Contains parameters related to geolocation."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt1r/sea_ice_segments/geolocation/rgt { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geolocation/rgt"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "Reference Ground track"; String source "Sea Ice ATBD"; String units "1"; Int16 valid_max 1387; Int16 valid_min 1; } /gt1r/sea_ice_segments/geolocation/sigma_lon { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geolocation/sigma_lon"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated uncertainty for the reference photon bounce point east longitude: 1- sigma (degrees). Applies to all other photons in the group."; String long_name "longitude uncertainty"; String source "Sea Ice ATBD"; String units "degrees"; } /gt1r/sea_ice_segments/geolocation/ref_atm_delay { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geolocation/ref_atm_delay"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Atmospheric path delay, in range, for the reference photon."; String long_name "Reference Photon Atm. Path Delay"; String source "Sea Ice ATBD"; String units "meters"; } /gt1r/sea_ice_segments/geolocation/beam_azimuth { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geolocation/beam_azimuth"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "beam azimuth"; String source "Sea Ice ATBD"; String units "degrees_east"; } /gt1r/sea_ice_segments/geolocation/solar_azimuth { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geolocation/solar_azimuth"; String contentType "physicalMeansurement"; String coordinates "../delta_time ../latitude ../longitude"; String description "The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot."; String long_name "solar azimuth"; String source "Sea Ice ATBD"; String units "degrees_east"; } /gt1r/sea_ice_segments/geolocation/ref_atm_delay_derivative { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geolocation/ref_atm_delay_derivative"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Atmospheric path delay derivative with respect to ellipsoid for the reference photon, in meters per meter."; String long_name "Derivative of Atm. Path Delay"; String source "Sea Ice ATBD"; String units "meters/meter"; } /gt1r/sea_ice_segments/geolocation/sigma_lat { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geolocation/sigma_lat"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated uncertainty for the reference photon bounce point geodetic latitude: 1- sigma (degrees). Applies to all other photons in the group"; String long_name "latitude uncertainty"; String source "Sea Ice ATBD"; String units "1"; } /gt1r/sea_ice_segments/geolocation/beam_coelev { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geolocation/beam_coelev"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Co-elevation (CE) is direction from vertical of the laser beam as seen by an observer located at the laser ground spot."; String long_name "beam co-elevation"; String source "Sea Ice ATBD"; String units "degrees"; } /gt1r/sea_ice_segments/geolocation/sigma_h { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geolocation/sigma_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "height uncertainty"; String source "Sea Ice ATBD"; String units "1"; } /gt1r/sea_ice_segments/geolocation/solar_elevation { String HDF5_OBJ_FULLPATH "/gt1r/sea_ice_segments/geolocation/solar_elevation"; String contentType "physicalMeansurement"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "solar elevation"; String source "Sea Ice ATBD"; String units "degrees"; } /gt2r/ { String HDF5_OBJ_FULLPATH "/gt2r/"; String Description "This ground contains parameters and subgroups related a specific groundtrack."; String data_rate "Each subgroup identifies its particular data rate."; String atlas_pce "pce2"; String atlas_beam_type "strong"; String groundtrack_id "gt2r"; String atmosphere_profile "profile_2"; String atlas_spot_number "3"; String sc_orientation "Forward"; } /gt2r/sea_ice_segments/ { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/"; String Description "Top group for sea ice segments as computed by the ATBD aglorithm"; String data_rate "Data within this group are stored at the variable segment rate."; } /gt2r/sea_ice_segments/heights/ { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/heights/"; String 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."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt2r/sea_ice_segments/heights/height_segment_fit_quality_flag { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/heights/height_segment_fit_quality_flag"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String flag_meanings "invalid best high med low poor"; Int16 flag_values -1, 1, 2, 3, 4, 5; String long_name "height Quality Flag"; String source "ATBD, section 4.2.4.2"; String units "1"; Int16 valid_max 5; Int16 valid_min -1; } /gt2r/sea_ice_segments/heights/height_segment_length_seg { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/heights/height_segment_length_seg"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "along-track length of segment containing n_photons_actual"; String long_name "length of segment"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2r/sea_ice_segments/heights/height_segment_asr_calc { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/heights/height_segment_asr_calc"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Computed apparent surface reflectance for the sea ice segment."; String long_name "Calculated Apparent Surface Reflectivity"; String source "Sea Ice ATBD"; String units "1"; } /gt2r/sea_ice_segments/heights/height_segment_quality { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/heights/height_segment_quality"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Height segment quality flag, 1 is good quality, 0 is bad depending on fit, wguassian, or layer flag"; String flag_meanings "bad_quality good_quality"; Int16 flag_values 0, 1; String long_name "Height Segment Quality Flag"; String source "ATBD, section 4.2.4"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt2r/sea_ice_segments/heights/height_segment_n_pulse_seg { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/heights/height_segment_n_pulse_seg"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "number of laser pulses"; String long_name "number of laser pulses"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt2r/sea_ice_segments/heights/across_track_distance { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/heights/across_track_distance"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Across track distance of photons averaged over the sea ice height segment."; String long_name "Across Track Distance"; String source "ATBD, section 4.2.4"; String units "meters"; } /gt2r/sea_ice_segments/heights/height_segment_htcorr_skew { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/heights/height_segment_htcorr_skew"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "height corection for skew"; String long_name "Height Correction for Skew"; String source "ATBD, section 4.2.6"; String units "meters"; } /gt2r/sea_ice_segments/heights/height_segment_ssh_flag { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/heights/height_segment_ssh_flag"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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"; String flag_meanings "sea_ice sea_surface"; Int16 flag_values 0, 1; String long_name "Sea Surface Flag"; String source "ATBD, section 4.3"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt2r/sea_ice_segments/heights/height_segment_height { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/heights/height_segment_height"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean height from along-track segment fit detremined by the sea ice algorithm"; String long_name "height of segment surface"; String source "ATBD, section 4.2.2.4"; String units "meters"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; } /gt2r/sea_ice_segments/heights/height_segment_type { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/heights/height_segment_type"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Value that indicates segment surface type as sea ice or different types of sea surface. 0=cloud covered: rsurf"; 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"; Int16 flag_values 0, 1, 2, 3, 4, 5, 6, 7, 8, 9; String long_name "Segment surface type"; String source "ATBD, section 4.3"; String units "1"; Int16 valid_max 9; Int16 valid_min 0; } /gt2r/sea_ice_segments/heights/height_segment_confidence { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/heights/height_segment_confidence"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Confidence level in the surface height estimate based on the number of photons; the background noise rate; and the error analysis"; String long_name "Surface height confidence"; String source "ATBD, section 4.2.4.2"; String units "1"; } /gt2r/sea_ice_segments/heights/height_segment_surface_error_est { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/heights/height_segment_surface_error_est"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Error estimate of the surface height"; String long_name "h surface error est"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2r/sea_ice_segments/heights/height_segment_w_gaussian { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/heights/height_segment_w_gaussian"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "width of best fit gaussian"; String long_name "width of best fit gaussian"; String source "ATBD, section 4.2.4"; String units "meters"; } /gt2r/sea_ice_segments/heights/height_segment_rms { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/heights/height_segment_rms"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "RMS difference between sea ice modeled and observed photon height distribution"; String long_name "height rms"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2r/sea_ice_segments/height_segment_id { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/height_segment_id"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Identifier of each height segment"; String long_name "Identifier of each height segment"; String source "ATBD, section 5.2"; String units "1"; } /gt2r/sea_ice_segments/seg_dist_x { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/seg_dist_x"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Along-track distance from the equator crossing to the segment center."; String long_name "Along track distance"; String source "Sea Ice ATBD"; String units "meters"; } /gt2r/sea_ice_segments/longitude { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/longitude"; String contentType "referenceInformation"; String coordinates "delta_time latitude"; String description "Longitude, WGS84, East=+,Lon of segment center"; String long_name "Longitude"; String source "ATBD, section 4.4"; String standard_name "longitude"; String units "degrees_east"; Float64 valid_max 180.; Float64 valid_min -180.; } /gt2r/sea_ice_segments/latitude { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/latitude"; String contentType "referenceInformation"; String coordinates "delta_time longitude"; String description "Latitude, WGS84, North=+, Lat of segment center"; String long_name "Latitude"; String source "ATBD, section 4.4"; String standard_name "latitude"; String units "degrees_north"; Float64 valid_max 90.; Float64 valid_min -90.; } /gt2r/sea_ice_segments/geophysical/ { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geophysical/"; String Description "Contains geophysical parameters and corrections used to correct photon heights for geophysical effects, such as tides."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt2r/sea_ice_segments/geophysical/height_segment_t2m { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geophysical/height_segment_t2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Temperature at 2m above the displacement height (K)"; String long_name "temperature_at_2m"; String source "ATL09"; String standard_name "temperature"; String units "K"; } /gt2r/sea_ice_segments/geophysical/height_segment_dac { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geophysical/height_segment_dac"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect."; String long_name "Dynamic Atmosphere Correction"; String source "Sea Ice ATBD"; String units "meters"; } /gt2r/sea_ice_segments/geophysical/height_segment_ps { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geophysical/height_segment_ps"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Sea Level Pressure (Pa)"; String long_name "sea level pressure"; String source "ATL09"; String standard_name "pressure"; String units "Pa"; } /gt2r/sea_ice_segments/geophysical/height_segment_ib { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geophysical/height_segment_ib"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Inverted barometer effect calculated from surface pressure"; String long_name "Inverted barometer effect"; String source "ATBD, section 4.2"; String units "meters"; } /gt2r/sea_ice_segments/geophysical/height_segment_load { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geophysical/height_segment_load"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Load Tide - Local displacement due to Ocean Loading (-6 to 0 cm)."; String long_name "Load Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt2r/sea_ice_segments/geophysical/height_segment_geoid { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geophysical/height_segment_geoid"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Geoid height above WGS-84 reference ellipsoid (range -107 to 86m), based on the EGM2008 model."; String long_name "EGM2008 Geoid"; String source "Sea Ice ATBD"; String units "meters"; } /gt2r/sea_ice_segments/geophysical/height_segment_ocean { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geophysical/height_segment_ocean"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Ocean Tides including diurnal and semi-diurnal (harmonic analysis), and longer period tides (dynamic and self-consistent equilibrium)"; String long_name "Ocean Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt2r/sea_ice_segments/geophysical/height_segment_v2m { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geophysical/height_segment_v2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Northward wind at 2m above the displacement height (m/s-1)"; String long_name "Northward_wind_at_2m"; String source "ATL09"; String standard_name "northward_wind"; String units "m s-1"; } /gt2r/sea_ice_segments/geophysical/height_segment_mss { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geophysical/height_segment_mss"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean sea surface height above WGS-84 reference ellipsoid (range: -105 to 87m), based on the DTU13 model."; String long_name "DTU13 Mean Sea Surface"; String source "Sea Ice ATBD"; String units "meters"; } /gt2r/sea_ice_segments/geophysical/height_segment_u2m { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geophysical/height_segment_u2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Eastward wind at 2m above the displacement height (m/s-1)"; String long_name "Eastward_wind_at_2m"; String source "ATL09"; String standard_name "eastward_wind"; String units "m s-1"; } /gt2r/sea_ice_segments/geophysical/height_segment_lpe { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geophysical/height_segment_lpe"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Long period equilibrium tide self-consistent with ocean tide model (+-0.04m). (dependent only on time and latitude)"; String long_name "Equilibrium Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt2r/sea_ice_segments/geophysical/height_segment_earth { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geophysical/height_segment_earth"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Solid Earth Tide"; String long_name "Earth Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt2r/sea_ice_segments/geophysical/height_segment_pole { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geophysical/height_segment_pole"; String coordinates "../delta_time ../latitude ../longitude"; String description "Pole Tide -Rotational deformation due to polar motion (-1.5 to 1.5 cm)."; String long_name "Pole Tide"; String source "Sea Ice ATBD"; String units "meters"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; } /gt2r/sea_ice_segments/geoseg_beg { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geoseg_beg"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Geolocation segment (geoseg) ID associated with the first photon used in this sea ice segment"; String long_name "Beginning GEOSEG"; String source "Sea Ice ATBD"; String units "1"; } /gt2r/sea_ice_segments/delta_time { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/delta_time"; String contentType "physicalMeasurement"; String coordinates "latitude longitude"; 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."; String long_name "Elapsed GPS seconds"; String source "telemetry"; String standard_name "time"; String units "seconds since 2018-01-01"; String CLASS "DIMENSION_SCALE"; String NAME "gt2r/sea_ice_segments/delta_time"; } /gt2r/sea_ice_segments/stats/ { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/"; String Description "Contains parameters related to quality and corrections on the sea ice height paramters"; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt2r/sea_ice_segments/stats/msw_flag { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/msw_flag"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; 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."; 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"; Int16 flag_values -1, 0, 1, 2, 3, 4, 5; String long_name "Multiple Scattering Warning Flag"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 5; Int16 valid_min -1; } /gt2r/sea_ice_segments/stats/hist_median_h { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/hist_median_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Median of the n_fit_photons heights"; String long_name "trimmed photon heights median"; String source "ATBD, section 4.2.3.1"; String units "meters"; } /gt2r/sea_ice_segments/stats/height_filter_min { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/height_filter_min"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height minimum used in the ssh height filter"; String long_name "Height Filter Min"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt2r/sea_ice_segments/stats/cloud_flag_atm { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/cloud_flag_atm"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of layers found from the backscatter profile using the DDA layer finder."; String long_name "Cloud Flag Atm"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 10; Int16 valid_min 0; } /gt2r/sea_ice_segments/stats/fpb_avg_dt { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/fpb_avg_dt"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction average dead time"; String long_name "fpb correction average deadtime"; String source "Sea Ice ATBD"; String units "ns"; } /gt2r/sea_ice_segments/stats/ds_si_hist_bins { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/ds_si_hist_bins"; String CLASS "DIMENSION_SCALE"; String NAME "ds_si_hist_bins"; String contentType "auxiliaryInformation"; 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."; String long_name "Sea Ice Histogram Bins Dimension Scale"; String source "SeaIce ATBD"; String units "1"; } /gt2r/sea_ice_segments/stats/fpb_strength { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/fpb_strength"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction strength"; String long_name "fpb correction strength"; String source "Sea Ice ATBD"; String units "photons/shot"; } /gt2r/sea_ice_segments/stats/bsnow_con { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/bsnow_con"; Int16 _FillValue 127; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Blowing snow confidence"; String long_name "Blowing snow confidence"; String source "ATL09"; String units "1"; } /gt2r/sea_ice_segments/stats/layer_flag { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/layer_flag"; String contentType "qualityInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String flag_meanings "likely_clear likely_cloudy"; Int16 flag_values 0, 1; String long_name "Consolidated cloud flag"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt2r/sea_ice_segments/stats/hist_photon_bin_size { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/hist_photon_bin_size"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "bin size of photon height histogram"; String long_name "height histogram bin size"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2r/sea_ice_segments/stats/backgr_calc { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/backgr_calc"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Calculated background count rate based on sun angle, surface slope, unit reflectance"; String long_name "background count rate calculated"; String source "ATBD, section 4.2.3"; String units "hz"; } /gt2r/sea_ice_segments/stats/fpb_corr { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/fpb_corr"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated first-photon bias(fpb) correction to mean segment height"; String long_name "first photon bias correction"; String source "Sea Ice ATBD"; String units "meters"; } /gt2r/sea_ice_segments/stats/bsnow_h { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/bsnow_h"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Blowing snow layer top height"; String long_name "Blowing snow top h"; String source "ATL09"; String units "meters"; } /gt2r/sea_ice_segments/stats/hist_photon_bottom { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/hist_photon_bottom"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "lower bound of height histogram"; String long_name "height histogram minimum"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2r/sea_ice_segments/stats/background_r_norm { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/background_r_norm"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background rate normalized to a fixed solar elevation angle"; String long_name "Normalized background (50-shot)"; String source "ATBD section 4.3.1.3"; String units "hz"; } /gt2r/sea_ice_segments/stats/exmax_mean_2 { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/exmax_mean_2"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mean 2"; String long_name "Exmax Mean 2"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt2r/sea_ice_segments/stats/background_int_height { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/background_int_height"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "The height of the altimetric range window after subtracting the height span of the signal photon events in the 50-shot span"; String long_name "Height of column used in background calculation"; String source "ATBD, section 7.3"; String units "meters"; } /gt2r/sea_ice_segments/stats/n_photons_actual { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/n_photons_actual"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons gathered"; String long_name "Number of photons found for the segment"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt2r/sea_ice_segments/stats/ice_conc { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/ice_conc"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "sea ice concentration"; String long_name "sea ice concentration"; String source "ATBD, section 3.1.4"; String units "1"; } /gt2r/sea_ice_segments/stats/exmax_stdev_2 { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/exmax_stdev_2"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height standard deviation 2"; String long_name "Exmax Stdev 2"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt2r/sea_ice_segments/stats/cloud_flag_asr { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/cloud_flag_asr"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; 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"; 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"; Int16 flag_values 0, 1, 2, 3, 4, 5, 6; String long_name "Cloud Flag ASR"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 6; Int16 valid_min 0; } /gt2r/sea_ice_segments/stats/exmax_stdev_1 { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/exmax_stdev_1"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height standard deviation 1"; String long_name "Exmax Stdev 1"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt2r/sea_ice_segments/stats/fpb_corr_width { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/fpb_corr_width"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction width"; String long_name "fpb correction width"; String source "Sea Ice ATBD"; String units "ns"; } /gt2r/sea_ice_segments/stats/height_coarse_stdev { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/height_coarse_stdev"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height standard deviation of coarse tracker"; String long_name "Coarse Height Sdev"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt2r/sea_ice_segments/stats/height_filter_05 { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/height_filter_05"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height fifth percentile used in the ssh height filter"; String long_name "Height Filter 5th Percentile"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt2r/sea_ice_segments/stats/n_photons_used { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/n_photons_used"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons in the trimmed histogram."; String long_name "Number of photons used for fit"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt2r/sea_ice_segments/stats/backgr_r_200 { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/backgr_r_200"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background count rate, averaged over the segment based on ATLAS 50 pulse counts"; String long_name "Background rate 200 hz"; String source "ATL09"; String units "hz"; } /gt2r/sea_ice_segments/stats/hist_photon_top { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/hist_photon_top"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "upper bound of height histogram"; String long_name "height histogram maximum"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2r/sea_ice_segments/stats/hist_w { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/hist_w"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Segment histogram width estimate"; String long_name "Segment histogram width estimate"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2r/sea_ice_segments/stats/hist_mean_h { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/hist_mean_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean of the n_fit_photons heights"; String long_name "photon heights mean"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2r/sea_ice_segments/stats/height_coarse_mn { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/height_coarse_mn"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height mean of coarse tracker"; String long_name "Coarse Track Height Mean"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt2r/sea_ice_segments/stats/exmax_mean_1 { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/exmax_mean_1"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mean 1"; String long_name "Exmax Mean 1"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt2r/sea_ice_segments/stats/hist_photon_heights { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/hist_photon_heights"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Histogram of the n_fit_photons heights"; String long_name "photon heights histogram"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt2r/sea_ice_segments/stats/trim_height_top { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/trim_height_top"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "maximum height of trimmed photons used in the surface calculation procedure"; String long_name "maximum height of trimmed photons"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2r/sea_ice_segments/stats/exmax_mix { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/exmax_mix"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mix ratio"; String long_name "Exmax Mix"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt2r/sea_ice_segments/stats/asr_25 { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/asr_25"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Apparent surface reflectance at 25 hz, averaged to the sea ice segment."; String long_name "Apparent Surface Reflectance 25hz"; String source "Sea Ice ATBD"; String units "1"; } /gt2r/sea_ice_segments/stats/photon_rate { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/photon_rate"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "photon count rate, averaged over segment"; String long_name "photon rate"; String source "ATBD, section 4.2.2.4"; String units "photons/shot"; } /gt2r/sea_ice_segments/stats/trim_height_bottom { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/trim_height_bottom"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "minimum height of trimmed photons used in the surface calculation procedure"; String long_name "minimum height of trimmed photons"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2r/sea_ice_segments/stats/n_photons_define { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/n_photons_define"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons to gather."; String long_name "Number of photons defining the segment"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt2r/sea_ice_segments/stats/backgr_r_25 { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/stats/backgr_r_25"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background count rate, averaged over the segment based on 25 hz atmosphere"; String long_name "Background rate 25hz"; String source "ATL09"; String units "hz"; } /gt2r/sea_ice_segments/geoseg_end { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geoseg_end"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Geolocation segment (geoseg) ID associated with the last photon used in this sea ice segment"; String long_name "Ending GEOSEG"; String source "Sea Ice ATBD"; String units "1"; } /gt2r/sea_ice_segments/geolocation/ { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geolocation/"; String Description "Contains parameters related to geolocation."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt2r/sea_ice_segments/geolocation/rgt { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geolocation/rgt"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "Reference Ground track"; String source "Sea Ice ATBD"; String units "1"; Int16 valid_max 1387; Int16 valid_min 1; } /gt2r/sea_ice_segments/geolocation/sigma_lon { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geolocation/sigma_lon"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated uncertainty for the reference photon bounce point east longitude: 1- sigma (degrees). Applies to all other photons in the group."; String long_name "longitude uncertainty"; String source "Sea Ice ATBD"; String units "degrees"; } /gt2r/sea_ice_segments/geolocation/ref_atm_delay { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geolocation/ref_atm_delay"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Atmospheric path delay, in range, for the reference photon."; String long_name "Reference Photon Atm. Path Delay"; String source "Sea Ice ATBD"; String units "meters"; } /gt2r/sea_ice_segments/geolocation/beam_azimuth { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geolocation/beam_azimuth"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "beam azimuth"; String source "Sea Ice ATBD"; String units "degrees_east"; } /gt2r/sea_ice_segments/geolocation/solar_azimuth { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geolocation/solar_azimuth"; String contentType "physicalMeansurement"; String coordinates "../delta_time ../latitude ../longitude"; String description "The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot."; String long_name "solar azimuth"; String source "Sea Ice ATBD"; String units "degrees_east"; } /gt2r/sea_ice_segments/geolocation/ref_atm_delay_derivative { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geolocation/ref_atm_delay_derivative"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Atmospheric path delay derivative with respect to ellipsoid for the reference photon, in meters per meter."; String long_name "Derivative of Atm. Path Delay"; String source "Sea Ice ATBD"; String units "meters/meter"; } /gt2r/sea_ice_segments/geolocation/sigma_lat { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geolocation/sigma_lat"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated uncertainty for the reference photon bounce point geodetic latitude: 1- sigma (degrees). Applies to all other photons in the group"; String long_name "latitude uncertainty"; String source "Sea Ice ATBD"; String units "1"; } /gt2r/sea_ice_segments/geolocation/beam_coelev { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geolocation/beam_coelev"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Co-elevation (CE) is direction from vertical of the laser beam as seen by an observer located at the laser ground spot."; String long_name "beam co-elevation"; String source "Sea Ice ATBD"; String units "degrees"; } /gt2r/sea_ice_segments/geolocation/sigma_h { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geolocation/sigma_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "height uncertainty"; String source "Sea Ice ATBD"; String units "1"; } /gt2r/sea_ice_segments/geolocation/solar_elevation { String HDF5_OBJ_FULLPATH "/gt2r/sea_ice_segments/geolocation/solar_elevation"; String contentType "physicalMeansurement"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "solar elevation"; String source "Sea Ice ATBD"; String units "degrees"; } /gt1l/ { String HDF5_OBJ_FULLPATH "/gt1l/"; String Description "This ground contains parameters and subgroups related a specific groundtrack."; String data_rate "Each subgroup identifies its particular data rate."; String atlas_pce "pce3"; String atlas_beam_type "weak"; String groundtrack_id "gt1l"; String atmosphere_profile "profile_1"; String atlas_spot_number "6"; String sc_orientation "Forward"; } /gt1l/sea_ice_segments/ { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/"; String Description "Top group for sea ice segments as computed by the ATBD aglorithm"; String data_rate "Data within this group are stored at the variable segment rate."; } /gt1l/sea_ice_segments/heights/ { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/heights/"; String 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."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt1l/sea_ice_segments/heights/height_segment_fit_quality_flag { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/heights/height_segment_fit_quality_flag"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String flag_meanings "invalid best high med low poor"; Int16 flag_values -1, 1, 2, 3, 4, 5; String long_name "height Quality Flag"; String source "ATBD, section 4.2.4.2"; String units "1"; Int16 valid_max 5; Int16 valid_min -1; } /gt1l/sea_ice_segments/heights/height_segment_length_seg { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/heights/height_segment_length_seg"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "along-track length of segment containing n_photons_actual"; String long_name "length of segment"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1l/sea_ice_segments/heights/height_segment_asr_calc { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/heights/height_segment_asr_calc"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Computed apparent surface reflectance for the sea ice segment."; String long_name "Calculated Apparent Surface Reflectivity"; String source "Sea Ice ATBD"; String units "1"; } /gt1l/sea_ice_segments/heights/height_segment_quality { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/heights/height_segment_quality"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Height segment quality flag, 1 is good quality, 0 is bad depending on fit, wguassian, or layer flag"; String flag_meanings "bad_quality good_quality"; Int16 flag_values 0, 1; String long_name "Height Segment Quality Flag"; String source "ATBD, section 4.2.4"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt1l/sea_ice_segments/heights/height_segment_n_pulse_seg { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/heights/height_segment_n_pulse_seg"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "number of laser pulses"; String long_name "number of laser pulses"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt1l/sea_ice_segments/heights/across_track_distance { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/heights/across_track_distance"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Across track distance of photons averaged over the sea ice height segment."; String long_name "Across Track Distance"; String source "ATBD, section 4.2.4"; String units "meters"; } /gt1l/sea_ice_segments/heights/height_segment_htcorr_skew { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/heights/height_segment_htcorr_skew"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "height corection for skew"; String long_name "Height Correction for Skew"; String source "ATBD, section 4.2.6"; String units "meters"; } /gt1l/sea_ice_segments/heights/height_segment_ssh_flag { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/heights/height_segment_ssh_flag"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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"; String flag_meanings "sea_ice sea_surface"; Int16 flag_values 0, 1; String long_name "Sea Surface Flag"; String source "ATBD, section 4.3"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt1l/sea_ice_segments/heights/height_segment_height { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/heights/height_segment_height"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean height from along-track segment fit detremined by the sea ice algorithm"; String long_name "height of segment surface"; String source "ATBD, section 4.2.2.4"; String units "meters"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; } /gt1l/sea_ice_segments/heights/height_segment_type { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/heights/height_segment_type"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Value that indicates segment surface type as sea ice or different types of sea surface. 0=cloud covered: rsurf"; 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"; Int16 flag_values 0, 1, 2, 3, 4, 5, 6, 7, 8, 9; String long_name "Segment surface type"; String source "ATBD, section 4.3"; String units "1"; Int16 valid_max 9; Int16 valid_min 0; } /gt1l/sea_ice_segments/heights/height_segment_confidence { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/heights/height_segment_confidence"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Confidence level in the surface height estimate based on the number of photons; the background noise rate; and the error analysis"; String long_name "Surface height confidence"; String source "ATBD, section 4.2.4.2"; String units "1"; } /gt1l/sea_ice_segments/heights/height_segment_surface_error_est { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/heights/height_segment_surface_error_est"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Error estimate of the surface height"; String long_name "h surface error est"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1l/sea_ice_segments/heights/height_segment_w_gaussian { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/heights/height_segment_w_gaussian"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "width of best fit gaussian"; String long_name "width of best fit gaussian"; String source "ATBD, section 4.2.4"; String units "meters"; } /gt1l/sea_ice_segments/heights/height_segment_rms { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/heights/height_segment_rms"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "RMS difference between sea ice modeled and observed photon height distribution"; String long_name "height rms"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1l/sea_ice_segments/height_segment_id { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/height_segment_id"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Identifier of each height segment"; String long_name "Identifier of each height segment"; String source "ATBD, section 5.2"; String units "1"; } /gt1l/sea_ice_segments/seg_dist_x { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/seg_dist_x"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Along-track distance from the equator crossing to the segment center."; String long_name "Along track distance"; String source "Sea Ice ATBD"; String units "meters"; } /gt1l/sea_ice_segments/longitude { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/longitude"; String contentType "referenceInformation"; String coordinates "delta_time latitude"; String description "Longitude, WGS84, East=+,Lon of segment center"; String long_name "Longitude"; String source "ATBD, section 4.4"; String standard_name "longitude"; String units "degrees_east"; Float64 valid_max 180.; Float64 valid_min -180.; } /gt1l/sea_ice_segments/latitude { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/latitude"; String contentType "referenceInformation"; String coordinates "delta_time longitude"; String description "Latitude, WGS84, North=+, Lat of segment center"; String long_name "Latitude"; String source "ATBD, section 4.4"; String standard_name "latitude"; String units "degrees_north"; Float64 valid_max 90.; Float64 valid_min -90.; } /gt1l/sea_ice_segments/geophysical/ { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geophysical/"; String Description "Contains geophysical parameters and corrections used to correct photon heights for geophysical effects, such as tides."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt1l/sea_ice_segments/geophysical/height_segment_t2m { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geophysical/height_segment_t2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Temperature at 2m above the displacement height (K)"; String long_name "temperature_at_2m"; String source "ATL09"; String standard_name "temperature"; String units "K"; } /gt1l/sea_ice_segments/geophysical/height_segment_dac { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geophysical/height_segment_dac"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect."; String long_name "Dynamic Atmosphere Correction"; String source "Sea Ice ATBD"; String units "meters"; } /gt1l/sea_ice_segments/geophysical/height_segment_ps { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geophysical/height_segment_ps"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Sea Level Pressure (Pa)"; String long_name "sea level pressure"; String source "ATL09"; String standard_name "pressure"; String units "Pa"; } /gt1l/sea_ice_segments/geophysical/height_segment_ib { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geophysical/height_segment_ib"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Inverted barometer effect calculated from surface pressure"; String long_name "Inverted barometer effect"; String source "ATBD, section 4.2"; String units "meters"; } /gt1l/sea_ice_segments/geophysical/height_segment_load { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geophysical/height_segment_load"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Load Tide - Local displacement due to Ocean Loading (-6 to 0 cm)."; String long_name "Load Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt1l/sea_ice_segments/geophysical/height_segment_geoid { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geophysical/height_segment_geoid"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Geoid height above WGS-84 reference ellipsoid (range -107 to 86m), based on the EGM2008 model."; String long_name "EGM2008 Geoid"; String source "Sea Ice ATBD"; String units "meters"; } /gt1l/sea_ice_segments/geophysical/height_segment_ocean { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geophysical/height_segment_ocean"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Ocean Tides including diurnal and semi-diurnal (harmonic analysis), and longer period tides (dynamic and self-consistent equilibrium)"; String long_name "Ocean Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt1l/sea_ice_segments/geophysical/height_segment_v2m { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geophysical/height_segment_v2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Northward wind at 2m above the displacement height (m/s-1)"; String long_name "Northward_wind_at_2m"; String source "ATL09"; String standard_name "northward_wind"; String units "m s-1"; } /gt1l/sea_ice_segments/geophysical/height_segment_mss { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geophysical/height_segment_mss"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean sea surface height above WGS-84 reference ellipsoid (range: -105 to 87m), based on the DTU13 model."; String long_name "DTU13 Mean Sea Surface"; String source "Sea Ice ATBD"; String units "meters"; } /gt1l/sea_ice_segments/geophysical/height_segment_u2m { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geophysical/height_segment_u2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Eastward wind at 2m above the displacement height (m/s-1)"; String long_name "Eastward_wind_at_2m"; String source "ATL09"; String standard_name "eastward_wind"; String units "m s-1"; } /gt1l/sea_ice_segments/geophysical/height_segment_lpe { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geophysical/height_segment_lpe"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Long period equilibrium tide self-consistent with ocean tide model (+-0.04m). (dependent only on time and latitude)"; String long_name "Equilibrium Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt1l/sea_ice_segments/geophysical/height_segment_earth { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geophysical/height_segment_earth"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Solid Earth Tide"; String long_name "Earth Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt1l/sea_ice_segments/geophysical/height_segment_pole { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geophysical/height_segment_pole"; String coordinates "../delta_time ../latitude ../longitude"; String description "Pole Tide -Rotational deformation due to polar motion (-1.5 to 1.5 cm)."; String long_name "Pole Tide"; String source "Sea Ice ATBD"; String units "meters"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; } /gt1l/sea_ice_segments/geoseg_beg { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geoseg_beg"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Geolocation segment (geoseg) ID associated with the first photon used in this sea ice segment"; String long_name "Beginning GEOSEG"; String source "Sea Ice ATBD"; String units "1"; } /gt1l/sea_ice_segments/delta_time { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/delta_time"; String contentType "physicalMeasurement"; String coordinates "latitude longitude"; 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."; String long_name "Elapsed GPS seconds"; String source "telemetry"; String standard_name "time"; String units "seconds since 2018-01-01"; String CLASS "DIMENSION_SCALE"; String NAME "gt1l/sea_ice_segments/delta_time"; } /gt1l/sea_ice_segments/stats/ { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/"; String Description "Contains parameters related to quality and corrections on the sea ice height paramters"; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt1l/sea_ice_segments/stats/msw_flag { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/msw_flag"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; 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."; 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"; Int16 flag_values -1, 0, 1, 2, 3, 4, 5; String long_name "Multiple Scattering Warning Flag"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 5; Int16 valid_min -1; } /gt1l/sea_ice_segments/stats/hist_median_h { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/hist_median_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Median of the n_fit_photons heights"; String long_name "trimmed photon heights median"; String source "ATBD, section 4.2.3.1"; String units "meters"; } /gt1l/sea_ice_segments/stats/height_filter_min { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/height_filter_min"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height minimum used in the ssh height filter"; String long_name "Height Filter Min"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt1l/sea_ice_segments/stats/cloud_flag_atm { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/cloud_flag_atm"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of layers found from the backscatter profile using the DDA layer finder."; String long_name "Cloud Flag Atm"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 10; Int16 valid_min 0; } /gt1l/sea_ice_segments/stats/fpb_avg_dt { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/fpb_avg_dt"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction average dead time"; String long_name "fpb correction average deadtime"; String source "Sea Ice ATBD"; String units "ns"; } /gt1l/sea_ice_segments/stats/ds_si_hist_bins { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/ds_si_hist_bins"; String CLASS "DIMENSION_SCALE"; String NAME "ds_si_hist_bins"; String contentType "auxiliaryInformation"; 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."; String long_name "Sea Ice Histogram Bins Dimension Scale"; String source "SeaIce ATBD"; String units "1"; } /gt1l/sea_ice_segments/stats/fpb_strength { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/fpb_strength"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction strength"; String long_name "fpb correction strength"; String source "Sea Ice ATBD"; String units "photons/shot"; } /gt1l/sea_ice_segments/stats/bsnow_con { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/bsnow_con"; Int16 _FillValue 127; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Blowing snow confidence"; String long_name "Blowing snow confidence"; String source "ATL09"; String units "1"; } /gt1l/sea_ice_segments/stats/layer_flag { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/layer_flag"; String contentType "qualityInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String flag_meanings "likely_clear likely_cloudy"; Int16 flag_values 0, 1; String long_name "Consolidated cloud flag"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt1l/sea_ice_segments/stats/hist_photon_bin_size { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/hist_photon_bin_size"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "bin size of photon height histogram"; String long_name "height histogram bin size"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1l/sea_ice_segments/stats/backgr_calc { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/backgr_calc"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Calculated background count rate based on sun angle, surface slope, unit reflectance"; String long_name "background count rate calculated"; String source "ATBD, section 4.2.3"; String units "hz"; } /gt1l/sea_ice_segments/stats/fpb_corr { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/fpb_corr"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated first-photon bias(fpb) correction to mean segment height"; String long_name "first photon bias correction"; String source "Sea Ice ATBD"; String units "meters"; } /gt1l/sea_ice_segments/stats/bsnow_h { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/bsnow_h"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Blowing snow layer top height"; String long_name "Blowing snow top h"; String source "ATL09"; String units "meters"; } /gt1l/sea_ice_segments/stats/hist_photon_bottom { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/hist_photon_bottom"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "lower bound of height histogram"; String long_name "height histogram minimum"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1l/sea_ice_segments/stats/background_r_norm { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/background_r_norm"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background rate normalized to a fixed solar elevation angle"; String long_name "Normalized background (50-shot)"; String source "ATBD section 4.3.1.3"; String units "hz"; } /gt1l/sea_ice_segments/stats/exmax_mean_2 { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/exmax_mean_2"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mean 2"; String long_name "Exmax Mean 2"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt1l/sea_ice_segments/stats/background_int_height { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/background_int_height"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "The height of the altimetric range window after subtracting the height span of the signal photon events in the 50-shot span"; String long_name "Height of column used in background calculation"; String source "ATBD, section 7.3"; String units "meters"; } /gt1l/sea_ice_segments/stats/n_photons_actual { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/n_photons_actual"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons gathered"; String long_name "Number of photons found for the segment"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt1l/sea_ice_segments/stats/ice_conc { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/ice_conc"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "sea ice concentration"; String long_name "sea ice concentration"; String source "ATBD, section 3.1.4"; String units "1"; } /gt1l/sea_ice_segments/stats/exmax_stdev_2 { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/exmax_stdev_2"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height standard deviation 2"; String long_name "Exmax Stdev 2"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt1l/sea_ice_segments/stats/cloud_flag_asr { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/cloud_flag_asr"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; 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"; 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"; Int16 flag_values 0, 1, 2, 3, 4, 5, 6; String long_name "Cloud Flag ASR"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 6; Int16 valid_min 0; } /gt1l/sea_ice_segments/stats/exmax_stdev_1 { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/exmax_stdev_1"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height standard deviation 1"; String long_name "Exmax Stdev 1"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt1l/sea_ice_segments/stats/fpb_corr_width { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/fpb_corr_width"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction width"; String long_name "fpb correction width"; String source "Sea Ice ATBD"; String units "ns"; } /gt1l/sea_ice_segments/stats/height_coarse_stdev { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/height_coarse_stdev"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height standard deviation of coarse tracker"; String long_name "Coarse Height Sdev"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt1l/sea_ice_segments/stats/height_filter_05 { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/height_filter_05"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height fifth percentile used in the ssh height filter"; String long_name "Height Filter 5th Percentile"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt1l/sea_ice_segments/stats/n_photons_used { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/n_photons_used"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons in the trimmed histogram."; String long_name "Number of photons used for fit"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt1l/sea_ice_segments/stats/backgr_r_200 { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/backgr_r_200"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background count rate, averaged over the segment based on ATLAS 50 pulse counts"; String long_name "Background rate 200 hz"; String source "ATL09"; String units "hz"; } /gt1l/sea_ice_segments/stats/hist_photon_top { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/hist_photon_top"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "upper bound of height histogram"; String long_name "height histogram maximum"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1l/sea_ice_segments/stats/hist_w { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/hist_w"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Segment histogram width estimate"; String long_name "Segment histogram width estimate"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1l/sea_ice_segments/stats/hist_mean_h { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/hist_mean_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean of the n_fit_photons heights"; String long_name "photon heights mean"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1l/sea_ice_segments/stats/height_coarse_mn { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/height_coarse_mn"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height mean of coarse tracker"; String long_name "Coarse Track Height Mean"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt1l/sea_ice_segments/stats/exmax_mean_1 { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/exmax_mean_1"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mean 1"; String long_name "Exmax Mean 1"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt1l/sea_ice_segments/stats/hist_photon_heights { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/hist_photon_heights"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Histogram of the n_fit_photons heights"; String long_name "photon heights histogram"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt1l/sea_ice_segments/stats/trim_height_top { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/trim_height_top"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "maximum height of trimmed photons used in the surface calculation procedure"; String long_name "maximum height of trimmed photons"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1l/sea_ice_segments/stats/exmax_mix { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/exmax_mix"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mix ratio"; String long_name "Exmax Mix"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt1l/sea_ice_segments/stats/asr_25 { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/asr_25"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Apparent surface reflectance at 25 hz, averaged to the sea ice segment."; String long_name "Apparent Surface Reflectance 25hz"; String source "Sea Ice ATBD"; String units "1"; } /gt1l/sea_ice_segments/stats/photon_rate { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/photon_rate"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "photon count rate, averaged over segment"; String long_name "photon rate"; String source "ATBD, section 4.2.2.4"; String units "photons/shot"; } /gt1l/sea_ice_segments/stats/trim_height_bottom { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/trim_height_bottom"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "minimum height of trimmed photons used in the surface calculation procedure"; String long_name "minimum height of trimmed photons"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt1l/sea_ice_segments/stats/n_photons_define { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/n_photons_define"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons to gather."; String long_name "Number of photons defining the segment"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt1l/sea_ice_segments/stats/backgr_r_25 { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/stats/backgr_r_25"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background count rate, averaged over the segment based on 25 hz atmosphere"; String long_name "Background rate 25hz"; String source "ATL09"; String units "hz"; } /gt1l/sea_ice_segments/geoseg_end { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geoseg_end"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Geolocation segment (geoseg) ID associated with the last photon used in this sea ice segment"; String long_name "Ending GEOSEG"; String source "Sea Ice ATBD"; String units "1"; } /gt1l/sea_ice_segments/geolocation/ { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geolocation/"; String Description "Contains parameters related to geolocation."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt1l/sea_ice_segments/geolocation/rgt { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geolocation/rgt"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "Reference Ground track"; String source "Sea Ice ATBD"; String units "1"; Int16 valid_max 1387; Int16 valid_min 1; } /gt1l/sea_ice_segments/geolocation/sigma_lon { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geolocation/sigma_lon"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated uncertainty for the reference photon bounce point east longitude: 1- sigma (degrees). Applies to all other photons in the group."; String long_name "longitude uncertainty"; String source "Sea Ice ATBD"; String units "degrees"; } /gt1l/sea_ice_segments/geolocation/ref_atm_delay { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geolocation/ref_atm_delay"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Atmospheric path delay, in range, for the reference photon."; String long_name "Reference Photon Atm. Path Delay"; String source "Sea Ice ATBD"; String units "meters"; } /gt1l/sea_ice_segments/geolocation/beam_azimuth { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geolocation/beam_azimuth"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "beam azimuth"; String source "Sea Ice ATBD"; String units "degrees_east"; } /gt1l/sea_ice_segments/geolocation/solar_azimuth { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geolocation/solar_azimuth"; String contentType "physicalMeansurement"; String coordinates "../delta_time ../latitude ../longitude"; String description "The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot."; String long_name "solar azimuth"; String source "Sea Ice ATBD"; String units "degrees_east"; } /gt1l/sea_ice_segments/geolocation/ref_atm_delay_derivative { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geolocation/ref_atm_delay_derivative"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Atmospheric path delay derivative with respect to ellipsoid for the reference photon, in meters per meter."; String long_name "Derivative of Atm. Path Delay"; String source "Sea Ice ATBD"; String units "meters/meter"; } /gt1l/sea_ice_segments/geolocation/sigma_lat { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geolocation/sigma_lat"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated uncertainty for the reference photon bounce point geodetic latitude: 1- sigma (degrees). Applies to all other photons in the group"; String long_name "latitude uncertainty"; String source "Sea Ice ATBD"; String units "1"; } /gt1l/sea_ice_segments/geolocation/beam_coelev { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geolocation/beam_coelev"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Co-elevation (CE) is direction from vertical of the laser beam as seen by an observer located at the laser ground spot."; String long_name "beam co-elevation"; String source "Sea Ice ATBD"; String units "degrees"; } /gt1l/sea_ice_segments/geolocation/sigma_h { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geolocation/sigma_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "height uncertainty"; String source "Sea Ice ATBD"; String units "1"; } /gt1l/sea_ice_segments/geolocation/solar_elevation { String HDF5_OBJ_FULLPATH "/gt1l/sea_ice_segments/geolocation/solar_elevation"; String contentType "physicalMeansurement"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "solar elevation"; String source "Sea Ice ATBD"; String units "degrees"; } /quality_assessment/ { String HDF5_OBJ_FULLPATH "/quality_assessment/"; String Description "Contains quality assessment data. This may include QA counters, QA along-track data and/or QA summary data."; } /quality_assessment/qa_granule_fail_reason { String HDF5_OBJ_FULLPATH "/quality_assessment/qa_granule_fail_reason"; String contentType "qualityInformation"; 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."; String flag_meanings "no_failure PROCESS_ERROR INSUFFICIENT_OUTPUT failure_3 failure_4 OTHER_FAILURE"; Int32 flag_values 0, 1, 2, 3, 4, 5; String long_name "Granule Failure Reason"; String source "Operations"; String units "1"; Int32 valid_max 5; Int32 valid_min 0; } /quality_assessment/qa_granule_pass_fail { String HDF5_OBJ_FULLPATH "/quality_assessment/qa_granule_pass_fail"; String contentType "qualityInformation"; String description "Flag indicating granule quality. 0=granule passes automatic QA. 1=granule fails automatic QA."; String flag_meanings "PASS FAIL"; Int32 flag_values 0, 1; String long_name "Granule Pass Flag"; String source "Operations"; String units "1"; Int32 valid_max 1; Int32 valid_min 0; } /gt3l/ { String HDF5_OBJ_FULLPATH "/gt3l/"; String Description "This ground contains parameters and subgroups related a specific groundtrack."; String data_rate "Each subgroup identifies its particular data rate."; String atlas_pce "pce1"; String atlas_beam_type "weak"; String groundtrack_id "gt3l"; String atmosphere_profile "profile_3"; String atlas_spot_number "2"; String sc_orientation "Forward"; } /gt3l/sea_ice_segments/ { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/"; String Description "Top group for sea ice segments as computed by the ATBD aglorithm"; String data_rate "Data within this group are stored at the variable segment rate."; } /gt3l/sea_ice_segments/heights/ { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/heights/"; String 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."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt3l/sea_ice_segments/heights/height_segment_fit_quality_flag { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/heights/height_segment_fit_quality_flag"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String flag_meanings "invalid best high med low poor"; Int16 flag_values -1, 1, 2, 3, 4, 5; String long_name "height Quality Flag"; String source "ATBD, section 4.2.4.2"; String units "1"; Int16 valid_max 5; Int16 valid_min -1; } /gt3l/sea_ice_segments/heights/height_segment_length_seg { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/heights/height_segment_length_seg"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "along-track length of segment containing n_photons_actual"; String long_name "length of segment"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3l/sea_ice_segments/heights/height_segment_asr_calc { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/heights/height_segment_asr_calc"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Computed apparent surface reflectance for the sea ice segment."; String long_name "Calculated Apparent Surface Reflectivity"; String source "Sea Ice ATBD"; String units "1"; } /gt3l/sea_ice_segments/heights/height_segment_quality { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/heights/height_segment_quality"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Height segment quality flag, 1 is good quality, 0 is bad depending on fit, wguassian, or layer flag"; String flag_meanings "bad_quality good_quality"; Int16 flag_values 0, 1; String long_name "Height Segment Quality Flag"; String source "ATBD, section 4.2.4"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt3l/sea_ice_segments/heights/height_segment_n_pulse_seg { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/heights/height_segment_n_pulse_seg"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "number of laser pulses"; String long_name "number of laser pulses"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt3l/sea_ice_segments/heights/across_track_distance { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/heights/across_track_distance"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Across track distance of photons averaged over the sea ice height segment."; String long_name "Across Track Distance"; String source "ATBD, section 4.2.4"; String units "meters"; } /gt3l/sea_ice_segments/heights/height_segment_htcorr_skew { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/heights/height_segment_htcorr_skew"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "height corection for skew"; String long_name "Height Correction for Skew"; String source "ATBD, section 4.2.6"; String units "meters"; } /gt3l/sea_ice_segments/heights/height_segment_ssh_flag { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/heights/height_segment_ssh_flag"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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"; String flag_meanings "sea_ice sea_surface"; Int16 flag_values 0, 1; String long_name "Sea Surface Flag"; String source "ATBD, section 4.3"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt3l/sea_ice_segments/heights/height_segment_height { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/heights/height_segment_height"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean height from along-track segment fit detremined by the sea ice algorithm"; String long_name "height of segment surface"; String source "ATBD, section 4.2.2.4"; String units "meters"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; } /gt3l/sea_ice_segments/heights/height_segment_type { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/heights/height_segment_type"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Value that indicates segment surface type as sea ice or different types of sea surface. 0=cloud covered: rsurf"; 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"; Int16 flag_values 0, 1, 2, 3, 4, 5, 6, 7, 8, 9; String long_name "Segment surface type"; String source "ATBD, section 4.3"; String units "1"; Int16 valid_max 9; Int16 valid_min 0; } /gt3l/sea_ice_segments/heights/height_segment_confidence { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/heights/height_segment_confidence"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Confidence level in the surface height estimate based on the number of photons; the background noise rate; and the error analysis"; String long_name "Surface height confidence"; String source "ATBD, section 4.2.4.2"; String units "1"; } /gt3l/sea_ice_segments/heights/height_segment_surface_error_est { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/heights/height_segment_surface_error_est"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Error estimate of the surface height"; String long_name "h surface error est"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3l/sea_ice_segments/heights/height_segment_w_gaussian { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/heights/height_segment_w_gaussian"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "width of best fit gaussian"; String long_name "width of best fit gaussian"; String source "ATBD, section 4.2.4"; String units "meters"; } /gt3l/sea_ice_segments/heights/height_segment_rms { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/heights/height_segment_rms"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "RMS difference between sea ice modeled and observed photon height distribution"; String long_name "height rms"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3l/sea_ice_segments/height_segment_id { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/height_segment_id"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Identifier of each height segment"; String long_name "Identifier of each height segment"; String source "ATBD, section 5.2"; String units "1"; } /gt3l/sea_ice_segments/seg_dist_x { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/seg_dist_x"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Along-track distance from the equator crossing to the segment center."; String long_name "Along track distance"; String source "Sea Ice ATBD"; String units "meters"; } /gt3l/sea_ice_segments/longitude { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/longitude"; String contentType "referenceInformation"; String coordinates "delta_time latitude"; String description "Longitude, WGS84, East=+,Lon of segment center"; String long_name "Longitude"; String source "ATBD, section 4.4"; String standard_name "longitude"; String units "degrees_east"; Float64 valid_max 180.; Float64 valid_min -180.; } /gt3l/sea_ice_segments/latitude { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/latitude"; String contentType "referenceInformation"; String coordinates "delta_time longitude"; String description "Latitude, WGS84, North=+, Lat of segment center"; String long_name "Latitude"; String source "ATBD, section 4.4"; String standard_name "latitude"; String units "degrees_north"; Float64 valid_max 90.; Float64 valid_min -90.; } /gt3l/sea_ice_segments/geophysical/ { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geophysical/"; String Description "Contains geophysical parameters and corrections used to correct photon heights for geophysical effects, such as tides."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt3l/sea_ice_segments/geophysical/height_segment_t2m { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geophysical/height_segment_t2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Temperature at 2m above the displacement height (K)"; String long_name "temperature_at_2m"; String source "ATL09"; String standard_name "temperature"; String units "K"; } /gt3l/sea_ice_segments/geophysical/height_segment_dac { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geophysical/height_segment_dac"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect."; String long_name "Dynamic Atmosphere Correction"; String source "Sea Ice ATBD"; String units "meters"; } /gt3l/sea_ice_segments/geophysical/height_segment_ps { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geophysical/height_segment_ps"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Sea Level Pressure (Pa)"; String long_name "sea level pressure"; String source "ATL09"; String standard_name "pressure"; String units "Pa"; } /gt3l/sea_ice_segments/geophysical/height_segment_ib { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geophysical/height_segment_ib"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Inverted barometer effect calculated from surface pressure"; String long_name "Inverted barometer effect"; String source "ATBD, section 4.2"; String units "meters"; } /gt3l/sea_ice_segments/geophysical/height_segment_load { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geophysical/height_segment_load"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Load Tide - Local displacement due to Ocean Loading (-6 to 0 cm)."; String long_name "Load Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt3l/sea_ice_segments/geophysical/height_segment_geoid { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geophysical/height_segment_geoid"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Geoid height above WGS-84 reference ellipsoid (range -107 to 86m), based on the EGM2008 model."; String long_name "EGM2008 Geoid"; String source "Sea Ice ATBD"; String units "meters"; } /gt3l/sea_ice_segments/geophysical/height_segment_ocean { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geophysical/height_segment_ocean"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Ocean Tides including diurnal and semi-diurnal (harmonic analysis), and longer period tides (dynamic and self-consistent equilibrium)"; String long_name "Ocean Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt3l/sea_ice_segments/geophysical/height_segment_v2m { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geophysical/height_segment_v2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Northward wind at 2m above the displacement height (m/s-1)"; String long_name "Northward_wind_at_2m"; String source "ATL09"; String standard_name "northward_wind"; String units "m s-1"; } /gt3l/sea_ice_segments/geophysical/height_segment_mss { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geophysical/height_segment_mss"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean sea surface height above WGS-84 reference ellipsoid (range: -105 to 87m), based on the DTU13 model."; String long_name "DTU13 Mean Sea Surface"; String source "Sea Ice ATBD"; String units "meters"; } /gt3l/sea_ice_segments/geophysical/height_segment_u2m { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geophysical/height_segment_u2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Eastward wind at 2m above the displacement height (m/s-1)"; String long_name "Eastward_wind_at_2m"; String source "ATL09"; String standard_name "eastward_wind"; String units "m s-1"; } /gt3l/sea_ice_segments/geophysical/height_segment_lpe { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geophysical/height_segment_lpe"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Long period equilibrium tide self-consistent with ocean tide model (+-0.04m). (dependent only on time and latitude)"; String long_name "Equilibrium Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt3l/sea_ice_segments/geophysical/height_segment_earth { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geophysical/height_segment_earth"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Solid Earth Tide"; String long_name "Earth Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt3l/sea_ice_segments/geophysical/height_segment_pole { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geophysical/height_segment_pole"; String coordinates "../delta_time ../latitude ../longitude"; String description "Pole Tide -Rotational deformation due to polar motion (-1.5 to 1.5 cm)."; String long_name "Pole Tide"; String source "Sea Ice ATBD"; String units "meters"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; } /gt3l/sea_ice_segments/geoseg_beg { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geoseg_beg"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Geolocation segment (geoseg) ID associated with the first photon used in this sea ice segment"; String long_name "Beginning GEOSEG"; String source "Sea Ice ATBD"; String units "1"; } /gt3l/sea_ice_segments/delta_time { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/delta_time"; String contentType "physicalMeasurement"; String coordinates "latitude longitude"; 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."; String long_name "Elapsed GPS seconds"; String source "telemetry"; String standard_name "time"; String units "seconds since 2018-01-01"; String CLASS "DIMENSION_SCALE"; String NAME "gt3l/sea_ice_segments/delta_time"; } /gt3l/sea_ice_segments/stats/ { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/"; String Description "Contains parameters related to quality and corrections on the sea ice height paramters"; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt3l/sea_ice_segments/stats/msw_flag { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/msw_flag"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; 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."; 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"; Int16 flag_values -1, 0, 1, 2, 3, 4, 5; String long_name "Multiple Scattering Warning Flag"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 5; Int16 valid_min -1; } /gt3l/sea_ice_segments/stats/hist_median_h { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/hist_median_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Median of the n_fit_photons heights"; String long_name "trimmed photon heights median"; String source "ATBD, section 4.2.3.1"; String units "meters"; } /gt3l/sea_ice_segments/stats/height_filter_min { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/height_filter_min"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height minimum used in the ssh height filter"; String long_name "Height Filter Min"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt3l/sea_ice_segments/stats/cloud_flag_atm { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/cloud_flag_atm"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of layers found from the backscatter profile using the DDA layer finder."; String long_name "Cloud Flag Atm"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 10; Int16 valid_min 0; } /gt3l/sea_ice_segments/stats/fpb_avg_dt { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/fpb_avg_dt"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction average dead time"; String long_name "fpb correction average deadtime"; String source "Sea Ice ATBD"; String units "ns"; } /gt3l/sea_ice_segments/stats/ds_si_hist_bins { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/ds_si_hist_bins"; String CLASS "DIMENSION_SCALE"; String NAME "ds_si_hist_bins"; String contentType "auxiliaryInformation"; 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."; String long_name "Sea Ice Histogram Bins Dimension Scale"; String source "SeaIce ATBD"; String units "1"; } /gt3l/sea_ice_segments/stats/fpb_strength { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/fpb_strength"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction strength"; String long_name "fpb correction strength"; String source "Sea Ice ATBD"; String units "photons/shot"; } /gt3l/sea_ice_segments/stats/bsnow_con { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/bsnow_con"; Int16 _FillValue 127; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Blowing snow confidence"; String long_name "Blowing snow confidence"; String source "ATL09"; String units "1"; } /gt3l/sea_ice_segments/stats/layer_flag { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/layer_flag"; String contentType "qualityInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String flag_meanings "likely_clear likely_cloudy"; Int16 flag_values 0, 1; String long_name "Consolidated cloud flag"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt3l/sea_ice_segments/stats/hist_photon_bin_size { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/hist_photon_bin_size"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "bin size of photon height histogram"; String long_name "height histogram bin size"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3l/sea_ice_segments/stats/backgr_calc { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/backgr_calc"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Calculated background count rate based on sun angle, surface slope, unit reflectance"; String long_name "background count rate calculated"; String source "ATBD, section 4.2.3"; String units "hz"; } /gt3l/sea_ice_segments/stats/fpb_corr { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/fpb_corr"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated first-photon bias(fpb) correction to mean segment height"; String long_name "first photon bias correction"; String source "Sea Ice ATBD"; String units "meters"; } /gt3l/sea_ice_segments/stats/bsnow_h { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/bsnow_h"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Blowing snow layer top height"; String long_name "Blowing snow top h"; String source "ATL09"; String units "meters"; } /gt3l/sea_ice_segments/stats/hist_photon_bottom { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/hist_photon_bottom"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "lower bound of height histogram"; String long_name "height histogram minimum"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3l/sea_ice_segments/stats/background_r_norm { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/background_r_norm"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background rate normalized to a fixed solar elevation angle"; String long_name "Normalized background (50-shot)"; String source "ATBD section 4.3.1.3"; String units "hz"; } /gt3l/sea_ice_segments/stats/exmax_mean_2 { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/exmax_mean_2"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mean 2"; String long_name "Exmax Mean 2"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt3l/sea_ice_segments/stats/background_int_height { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/background_int_height"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "The height of the altimetric range window after subtracting the height span of the signal photon events in the 50-shot span"; String long_name "Height of column used in background calculation"; String source "ATBD, section 7.3"; String units "meters"; } /gt3l/sea_ice_segments/stats/n_photons_actual { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/n_photons_actual"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons gathered"; String long_name "Number of photons found for the segment"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt3l/sea_ice_segments/stats/ice_conc { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/ice_conc"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "sea ice concentration"; String long_name "sea ice concentration"; String source "ATBD, section 3.1.4"; String units "1"; } /gt3l/sea_ice_segments/stats/exmax_stdev_2 { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/exmax_stdev_2"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height standard deviation 2"; String long_name "Exmax Stdev 2"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt3l/sea_ice_segments/stats/cloud_flag_asr { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/cloud_flag_asr"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; 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"; 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"; Int16 flag_values 0, 1, 2, 3, 4, 5, 6; String long_name "Cloud Flag ASR"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 6; Int16 valid_min 0; } /gt3l/sea_ice_segments/stats/exmax_stdev_1 { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/exmax_stdev_1"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height standard deviation 1"; String long_name "Exmax Stdev 1"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt3l/sea_ice_segments/stats/fpb_corr_width { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/fpb_corr_width"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction width"; String long_name "fpb correction width"; String source "Sea Ice ATBD"; String units "ns"; } /gt3l/sea_ice_segments/stats/height_coarse_stdev { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/height_coarse_stdev"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height standard deviation of coarse tracker"; String long_name "Coarse Height Sdev"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt3l/sea_ice_segments/stats/height_filter_05 { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/height_filter_05"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height fifth percentile used in the ssh height filter"; String long_name "Height Filter 5th Percentile"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt3l/sea_ice_segments/stats/n_photons_used { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/n_photons_used"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons in the trimmed histogram."; String long_name "Number of photons used for fit"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt3l/sea_ice_segments/stats/backgr_r_200 { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/backgr_r_200"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background count rate, averaged over the segment based on ATLAS 50 pulse counts"; String long_name "Background rate 200 hz"; String source "ATL09"; String units "hz"; } /gt3l/sea_ice_segments/stats/hist_photon_top { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/hist_photon_top"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "upper bound of height histogram"; String long_name "height histogram maximum"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3l/sea_ice_segments/stats/hist_w { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/hist_w"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Segment histogram width estimate"; String long_name "Segment histogram width estimate"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3l/sea_ice_segments/stats/hist_mean_h { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/hist_mean_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean of the n_fit_photons heights"; String long_name "photon heights mean"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3l/sea_ice_segments/stats/height_coarse_mn { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/height_coarse_mn"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height mean of coarse tracker"; String long_name "Coarse Track Height Mean"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt3l/sea_ice_segments/stats/exmax_mean_1 { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/exmax_mean_1"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mean 1"; String long_name "Exmax Mean 1"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt3l/sea_ice_segments/stats/hist_photon_heights { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/hist_photon_heights"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Histogram of the n_fit_photons heights"; String long_name "photon heights histogram"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt3l/sea_ice_segments/stats/trim_height_top { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/trim_height_top"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "maximum height of trimmed photons used in the surface calculation procedure"; String long_name "maximum height of trimmed photons"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3l/sea_ice_segments/stats/exmax_mix { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/exmax_mix"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mix ratio"; String long_name "Exmax Mix"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt3l/sea_ice_segments/stats/asr_25 { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/asr_25"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Apparent surface reflectance at 25 hz, averaged to the sea ice segment."; String long_name "Apparent Surface Reflectance 25hz"; String source "Sea Ice ATBD"; String units "1"; } /gt3l/sea_ice_segments/stats/photon_rate { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/photon_rate"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "photon count rate, averaged over segment"; String long_name "photon rate"; String source "ATBD, section 4.2.2.4"; String units "photons/shot"; } /gt3l/sea_ice_segments/stats/trim_height_bottom { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/trim_height_bottom"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "minimum height of trimmed photons used in the surface calculation procedure"; String long_name "minimum height of trimmed photons"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3l/sea_ice_segments/stats/n_photons_define { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/n_photons_define"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons to gather."; String long_name "Number of photons defining the segment"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt3l/sea_ice_segments/stats/backgr_r_25 { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/stats/backgr_r_25"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background count rate, averaged over the segment based on 25 hz atmosphere"; String long_name "Background rate 25hz"; String source "ATL09"; String units "hz"; } /gt3l/sea_ice_segments/geoseg_end { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geoseg_end"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Geolocation segment (geoseg) ID associated with the last photon used in this sea ice segment"; String long_name "Ending GEOSEG"; String source "Sea Ice ATBD"; String units "1"; } /gt3l/sea_ice_segments/geolocation/ { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geolocation/"; String Description "Contains parameters related to geolocation."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt3l/sea_ice_segments/geolocation/rgt { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geolocation/rgt"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "Reference Ground track"; String source "Sea Ice ATBD"; String units "1"; Int16 valid_max 1387; Int16 valid_min 1; } /gt3l/sea_ice_segments/geolocation/sigma_lon { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geolocation/sigma_lon"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated uncertainty for the reference photon bounce point east longitude: 1- sigma (degrees). Applies to all other photons in the group."; String long_name "longitude uncertainty"; String source "Sea Ice ATBD"; String units "degrees"; } /gt3l/sea_ice_segments/geolocation/ref_atm_delay { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geolocation/ref_atm_delay"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Atmospheric path delay, in range, for the reference photon."; String long_name "Reference Photon Atm. Path Delay"; String source "Sea Ice ATBD"; String units "meters"; } /gt3l/sea_ice_segments/geolocation/beam_azimuth { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geolocation/beam_azimuth"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "beam azimuth"; String source "Sea Ice ATBD"; String units "degrees_east"; } /gt3l/sea_ice_segments/geolocation/solar_azimuth { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geolocation/solar_azimuth"; String contentType "physicalMeansurement"; String coordinates "../delta_time ../latitude ../longitude"; String description "The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot."; String long_name "solar azimuth"; String source "Sea Ice ATBD"; String units "degrees_east"; } /gt3l/sea_ice_segments/geolocation/ref_atm_delay_derivative { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geolocation/ref_atm_delay_derivative"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Atmospheric path delay derivative with respect to ellipsoid for the reference photon, in meters per meter."; String long_name "Derivative of Atm. Path Delay"; String source "Sea Ice ATBD"; String units "meters/meter"; } /gt3l/sea_ice_segments/geolocation/sigma_lat { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geolocation/sigma_lat"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated uncertainty for the reference photon bounce point geodetic latitude: 1- sigma (degrees). Applies to all other photons in the group"; String long_name "latitude uncertainty"; String source "Sea Ice ATBD"; String units "1"; } /gt3l/sea_ice_segments/geolocation/beam_coelev { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geolocation/beam_coelev"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Co-elevation (CE) is direction from vertical of the laser beam as seen by an observer located at the laser ground spot."; String long_name "beam co-elevation"; String source "Sea Ice ATBD"; String units "degrees"; } /gt3l/sea_ice_segments/geolocation/sigma_h { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geolocation/sigma_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "height uncertainty"; String source "Sea Ice ATBD"; String units "1"; } /gt3l/sea_ice_segments/geolocation/solar_elevation { String HDF5_OBJ_FULLPATH "/gt3l/sea_ice_segments/geolocation/solar_elevation"; String contentType "physicalMeansurement"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "solar elevation"; String source "Sea Ice ATBD"; String units "degrees"; } /gt2l/ { String HDF5_OBJ_FULLPATH "/gt2l/"; String Description "This ground contains parameters and subgroups related a specific groundtrack."; String data_rate "Each subgroup identifies its particular data rate."; String atlas_pce "pce2"; String atlas_beam_type "weak"; String groundtrack_id "gt2l"; String atmosphere_profile "profile_2"; String atlas_spot_number "4"; String sc_orientation "Forward"; } /gt2l/sea_ice_segments/ { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/"; String Description "Top group for sea ice segments as computed by the ATBD aglorithm"; String data_rate "Data within this group are stored at the variable segment rate."; } /gt2l/sea_ice_segments/heights/ { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/heights/"; String 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."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt2l/sea_ice_segments/heights/height_segment_fit_quality_flag { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/heights/height_segment_fit_quality_flag"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String flag_meanings "invalid best high med low poor"; Int16 flag_values -1, 1, 2, 3, 4, 5; String long_name "height Quality Flag"; String source "ATBD, section 4.2.4.2"; String units "1"; Int16 valid_max 5; Int16 valid_min -1; } /gt2l/sea_ice_segments/heights/height_segment_length_seg { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/heights/height_segment_length_seg"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "along-track length of segment containing n_photons_actual"; String long_name "length of segment"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2l/sea_ice_segments/heights/height_segment_asr_calc { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/heights/height_segment_asr_calc"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Computed apparent surface reflectance for the sea ice segment."; String long_name "Calculated Apparent Surface Reflectivity"; String source "Sea Ice ATBD"; String units "1"; } /gt2l/sea_ice_segments/heights/height_segment_quality { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/heights/height_segment_quality"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Height segment quality flag, 1 is good quality, 0 is bad depending on fit, wguassian, or layer flag"; String flag_meanings "bad_quality good_quality"; Int16 flag_values 0, 1; String long_name "Height Segment Quality Flag"; String source "ATBD, section 4.2.4"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt2l/sea_ice_segments/heights/height_segment_n_pulse_seg { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/heights/height_segment_n_pulse_seg"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "number of laser pulses"; String long_name "number of laser pulses"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt2l/sea_ice_segments/heights/across_track_distance { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/heights/across_track_distance"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Across track distance of photons averaged over the sea ice height segment."; String long_name "Across Track Distance"; String source "ATBD, section 4.2.4"; String units "meters"; } /gt2l/sea_ice_segments/heights/height_segment_htcorr_skew { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/heights/height_segment_htcorr_skew"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "height corection for skew"; String long_name "Height Correction for Skew"; String source "ATBD, section 4.2.6"; String units "meters"; } /gt2l/sea_ice_segments/heights/height_segment_ssh_flag { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/heights/height_segment_ssh_flag"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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"; String flag_meanings "sea_ice sea_surface"; Int16 flag_values 0, 1; String long_name "Sea Surface Flag"; String source "ATBD, section 4.3"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt2l/sea_ice_segments/heights/height_segment_height { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/heights/height_segment_height"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean height from along-track segment fit detremined by the sea ice algorithm"; String long_name "height of segment surface"; String source "ATBD, section 4.2.2.4"; String units "meters"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; } /gt2l/sea_ice_segments/heights/height_segment_type { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/heights/height_segment_type"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Value that indicates segment surface type as sea ice or different types of sea surface. 0=cloud covered: rsurf"; 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"; Int16 flag_values 0, 1, 2, 3, 4, 5, 6, 7, 8, 9; String long_name "Segment surface type"; String source "ATBD, section 4.3"; String units "1"; Int16 valid_max 9; Int16 valid_min 0; } /gt2l/sea_ice_segments/heights/height_segment_confidence { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/heights/height_segment_confidence"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Confidence level in the surface height estimate based on the number of photons; the background noise rate; and the error analysis"; String long_name "Surface height confidence"; String source "ATBD, section 4.2.4.2"; String units "1"; } /gt2l/sea_ice_segments/heights/height_segment_surface_error_est { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/heights/height_segment_surface_error_est"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Error estimate of the surface height"; String long_name "h surface error est"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2l/sea_ice_segments/heights/height_segment_w_gaussian { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/heights/height_segment_w_gaussian"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "width of best fit gaussian"; String long_name "width of best fit gaussian"; String source "ATBD, section 4.2.4"; String units "meters"; } /gt2l/sea_ice_segments/heights/height_segment_rms { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/heights/height_segment_rms"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "RMS difference between sea ice modeled and observed photon height distribution"; String long_name "height rms"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2l/sea_ice_segments/height_segment_id { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/height_segment_id"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Identifier of each height segment"; String long_name "Identifier of each height segment"; String source "ATBD, section 5.2"; String units "1"; } /gt2l/sea_ice_segments/seg_dist_x { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/seg_dist_x"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Along-track distance from the equator crossing to the segment center."; String long_name "Along track distance"; String source "Sea Ice ATBD"; String units "meters"; } /gt2l/sea_ice_segments/longitude { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/longitude"; String contentType "referenceInformation"; String coordinates "delta_time latitude"; String description "Longitude, WGS84, East=+,Lon of segment center"; String long_name "Longitude"; String source "ATBD, section 4.4"; String standard_name "longitude"; String units "degrees_east"; Float64 valid_max 180.; Float64 valid_min -180.; } /gt2l/sea_ice_segments/latitude { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/latitude"; String contentType "referenceInformation"; String coordinates "delta_time longitude"; String description "Latitude, WGS84, North=+, Lat of segment center"; String long_name "Latitude"; String source "ATBD, section 4.4"; String standard_name "latitude"; String units "degrees_north"; Float64 valid_max 90.; Float64 valid_min -90.; } /gt2l/sea_ice_segments/geophysical/ { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geophysical/"; String Description "Contains geophysical parameters and corrections used to correct photon heights for geophysical effects, such as tides."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt2l/sea_ice_segments/geophysical/height_segment_t2m { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geophysical/height_segment_t2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Temperature at 2m above the displacement height (K)"; String long_name "temperature_at_2m"; String source "ATL09"; String standard_name "temperature"; String units "K"; } /gt2l/sea_ice_segments/geophysical/height_segment_dac { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geophysical/height_segment_dac"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect."; String long_name "Dynamic Atmosphere Correction"; String source "Sea Ice ATBD"; String units "meters"; } /gt2l/sea_ice_segments/geophysical/height_segment_ps { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geophysical/height_segment_ps"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Sea Level Pressure (Pa)"; String long_name "sea level pressure"; String source "ATL09"; String standard_name "pressure"; String units "Pa"; } /gt2l/sea_ice_segments/geophysical/height_segment_ib { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geophysical/height_segment_ib"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Inverted barometer effect calculated from surface pressure"; String long_name "Inverted barometer effect"; String source "ATBD, section 4.2"; String units "meters"; } /gt2l/sea_ice_segments/geophysical/height_segment_load { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geophysical/height_segment_load"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Load Tide - Local displacement due to Ocean Loading (-6 to 0 cm)."; String long_name "Load Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt2l/sea_ice_segments/geophysical/height_segment_geoid { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geophysical/height_segment_geoid"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Geoid height above WGS-84 reference ellipsoid (range -107 to 86m), based on the EGM2008 model."; String long_name "EGM2008 Geoid"; String source "Sea Ice ATBD"; String units "meters"; } /gt2l/sea_ice_segments/geophysical/height_segment_ocean { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geophysical/height_segment_ocean"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Ocean Tides including diurnal and semi-diurnal (harmonic analysis), and longer period tides (dynamic and self-consistent equilibrium)"; String long_name "Ocean Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt2l/sea_ice_segments/geophysical/height_segment_v2m { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geophysical/height_segment_v2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Northward wind at 2m above the displacement height (m/s-1)"; String long_name "Northward_wind_at_2m"; String source "ATL09"; String standard_name "northward_wind"; String units "m s-1"; } /gt2l/sea_ice_segments/geophysical/height_segment_mss { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geophysical/height_segment_mss"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean sea surface height above WGS-84 reference ellipsoid (range: -105 to 87m), based on the DTU13 model."; String long_name "DTU13 Mean Sea Surface"; String source "Sea Ice ATBD"; String units "meters"; } /gt2l/sea_ice_segments/geophysical/height_segment_u2m { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geophysical/height_segment_u2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Eastward wind at 2m above the displacement height (m/s-1)"; String long_name "Eastward_wind_at_2m"; String source "ATL09"; String standard_name "eastward_wind"; String units "m s-1"; } /gt2l/sea_ice_segments/geophysical/height_segment_lpe { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geophysical/height_segment_lpe"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Long period equilibrium tide self-consistent with ocean tide model (+-0.04m). (dependent only on time and latitude)"; String long_name "Equilibrium Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt2l/sea_ice_segments/geophysical/height_segment_earth { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geophysical/height_segment_earth"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Solid Earth Tide"; String long_name "Earth Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt2l/sea_ice_segments/geophysical/height_segment_pole { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geophysical/height_segment_pole"; String coordinates "../delta_time ../latitude ../longitude"; String description "Pole Tide -Rotational deformation due to polar motion (-1.5 to 1.5 cm)."; String long_name "Pole Tide"; String source "Sea Ice ATBD"; String units "meters"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; } /gt2l/sea_ice_segments/geoseg_beg { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geoseg_beg"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Geolocation segment (geoseg) ID associated with the first photon used in this sea ice segment"; String long_name "Beginning GEOSEG"; String source "Sea Ice ATBD"; String units "1"; } /gt2l/sea_ice_segments/delta_time { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/delta_time"; String contentType "physicalMeasurement"; String coordinates "latitude longitude"; 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."; String long_name "Elapsed GPS seconds"; String source "telemetry"; String standard_name "time"; String units "seconds since 2018-01-01"; String CLASS "DIMENSION_SCALE"; String NAME "gt2l/sea_ice_segments/delta_time"; } /gt2l/sea_ice_segments/stats/ { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/"; String Description "Contains parameters related to quality and corrections on the sea ice height paramters"; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt2l/sea_ice_segments/stats/msw_flag { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/msw_flag"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; 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."; 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"; Int16 flag_values -1, 0, 1, 2, 3, 4, 5; String long_name "Multiple Scattering Warning Flag"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 5; Int16 valid_min -1; } /gt2l/sea_ice_segments/stats/hist_median_h { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/hist_median_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Median of the n_fit_photons heights"; String long_name "trimmed photon heights median"; String source "ATBD, section 4.2.3.1"; String units "meters"; } /gt2l/sea_ice_segments/stats/height_filter_min { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/height_filter_min"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height minimum used in the ssh height filter"; String long_name "Height Filter Min"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt2l/sea_ice_segments/stats/cloud_flag_atm { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/cloud_flag_atm"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of layers found from the backscatter profile using the DDA layer finder."; String long_name "Cloud Flag Atm"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 10; Int16 valid_min 0; } /gt2l/sea_ice_segments/stats/fpb_avg_dt { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/fpb_avg_dt"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction average dead time"; String long_name "fpb correction average deadtime"; String source "Sea Ice ATBD"; String units "ns"; } /gt2l/sea_ice_segments/stats/ds_si_hist_bins { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/ds_si_hist_bins"; String CLASS "DIMENSION_SCALE"; String NAME "ds_si_hist_bins"; String contentType "auxiliaryInformation"; 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."; String long_name "Sea Ice Histogram Bins Dimension Scale"; String source "SeaIce ATBD"; String units "1"; } /gt2l/sea_ice_segments/stats/fpb_strength { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/fpb_strength"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction strength"; String long_name "fpb correction strength"; String source "Sea Ice ATBD"; String units "photons/shot"; } /gt2l/sea_ice_segments/stats/bsnow_con { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/bsnow_con"; Int16 _FillValue 127; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Blowing snow confidence"; String long_name "Blowing snow confidence"; String source "ATL09"; String units "1"; } /gt2l/sea_ice_segments/stats/layer_flag { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/layer_flag"; String contentType "qualityInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String flag_meanings "likely_clear likely_cloudy"; Int16 flag_values 0, 1; String long_name "Consolidated cloud flag"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt2l/sea_ice_segments/stats/hist_photon_bin_size { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/hist_photon_bin_size"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "bin size of photon height histogram"; String long_name "height histogram bin size"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2l/sea_ice_segments/stats/backgr_calc { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/backgr_calc"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Calculated background count rate based on sun angle, surface slope, unit reflectance"; String long_name "background count rate calculated"; String source "ATBD, section 4.2.3"; String units "hz"; } /gt2l/sea_ice_segments/stats/fpb_corr { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/fpb_corr"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated first-photon bias(fpb) correction to mean segment height"; String long_name "first photon bias correction"; String source "Sea Ice ATBD"; String units "meters"; } /gt2l/sea_ice_segments/stats/bsnow_h { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/bsnow_h"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Blowing snow layer top height"; String long_name "Blowing snow top h"; String source "ATL09"; String units "meters"; } /gt2l/sea_ice_segments/stats/hist_photon_bottom { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/hist_photon_bottom"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "lower bound of height histogram"; String long_name "height histogram minimum"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2l/sea_ice_segments/stats/background_r_norm { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/background_r_norm"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background rate normalized to a fixed solar elevation angle"; String long_name "Normalized background (50-shot)"; String source "ATBD section 4.3.1.3"; String units "hz"; } /gt2l/sea_ice_segments/stats/exmax_mean_2 { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/exmax_mean_2"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mean 2"; String long_name "Exmax Mean 2"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt2l/sea_ice_segments/stats/background_int_height { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/background_int_height"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "The height of the altimetric range window after subtracting the height span of the signal photon events in the 50-shot span"; String long_name "Height of column used in background calculation"; String source "ATBD, section 7.3"; String units "meters"; } /gt2l/sea_ice_segments/stats/n_photons_actual { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/n_photons_actual"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons gathered"; String long_name "Number of photons found for the segment"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt2l/sea_ice_segments/stats/ice_conc { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/ice_conc"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "sea ice concentration"; String long_name "sea ice concentration"; String source "ATBD, section 3.1.4"; String units "1"; } /gt2l/sea_ice_segments/stats/exmax_stdev_2 { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/exmax_stdev_2"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height standard deviation 2"; String long_name "Exmax Stdev 2"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt2l/sea_ice_segments/stats/cloud_flag_asr { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/cloud_flag_asr"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; 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"; 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"; Int16 flag_values 0, 1, 2, 3, 4, 5, 6; String long_name "Cloud Flag ASR"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 6; Int16 valid_min 0; } /gt2l/sea_ice_segments/stats/exmax_stdev_1 { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/exmax_stdev_1"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height standard deviation 1"; String long_name "Exmax Stdev 1"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt2l/sea_ice_segments/stats/fpb_corr_width { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/fpb_corr_width"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction width"; String long_name "fpb correction width"; String source "Sea Ice ATBD"; String units "ns"; } /gt2l/sea_ice_segments/stats/height_coarse_stdev { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/height_coarse_stdev"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height standard deviation of coarse tracker"; String long_name "Coarse Height Sdev"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt2l/sea_ice_segments/stats/height_filter_05 { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/height_filter_05"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height fifth percentile used in the ssh height filter"; String long_name "Height Filter 5th Percentile"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt2l/sea_ice_segments/stats/n_photons_used { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/n_photons_used"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons in the trimmed histogram."; String long_name "Number of photons used for fit"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt2l/sea_ice_segments/stats/backgr_r_200 { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/backgr_r_200"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background count rate, averaged over the segment based on ATLAS 50 pulse counts"; String long_name "Background rate 200 hz"; String source "ATL09"; String units "hz"; } /gt2l/sea_ice_segments/stats/hist_photon_top { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/hist_photon_top"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "upper bound of height histogram"; String long_name "height histogram maximum"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2l/sea_ice_segments/stats/hist_w { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/hist_w"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Segment histogram width estimate"; String long_name "Segment histogram width estimate"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2l/sea_ice_segments/stats/hist_mean_h { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/hist_mean_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean of the n_fit_photons heights"; String long_name "photon heights mean"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2l/sea_ice_segments/stats/height_coarse_mn { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/height_coarse_mn"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height mean of coarse tracker"; String long_name "Coarse Track Height Mean"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt2l/sea_ice_segments/stats/exmax_mean_1 { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/exmax_mean_1"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mean 1"; String long_name "Exmax Mean 1"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt2l/sea_ice_segments/stats/hist_photon_heights { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/hist_photon_heights"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Histogram of the n_fit_photons heights"; String long_name "photon heights histogram"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt2l/sea_ice_segments/stats/trim_height_top { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/trim_height_top"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "maximum height of trimmed photons used in the surface calculation procedure"; String long_name "maximum height of trimmed photons"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2l/sea_ice_segments/stats/exmax_mix { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/exmax_mix"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mix ratio"; String long_name "Exmax Mix"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt2l/sea_ice_segments/stats/asr_25 { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/asr_25"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Apparent surface reflectance at 25 hz, averaged to the sea ice segment."; String long_name "Apparent Surface Reflectance 25hz"; String source "Sea Ice ATBD"; String units "1"; } /gt2l/sea_ice_segments/stats/photon_rate { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/photon_rate"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "photon count rate, averaged over segment"; String long_name "photon rate"; String source "ATBD, section 4.2.2.4"; String units "photons/shot"; } /gt2l/sea_ice_segments/stats/trim_height_bottom { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/trim_height_bottom"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "minimum height of trimmed photons used in the surface calculation procedure"; String long_name "minimum height of trimmed photons"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt2l/sea_ice_segments/stats/n_photons_define { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/n_photons_define"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons to gather."; String long_name "Number of photons defining the segment"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt2l/sea_ice_segments/stats/backgr_r_25 { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/stats/backgr_r_25"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background count rate, averaged over the segment based on 25 hz atmosphere"; String long_name "Background rate 25hz"; String source "ATL09"; String units "hz"; } /gt2l/sea_ice_segments/geoseg_end { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geoseg_end"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Geolocation segment (geoseg) ID associated with the last photon used in this sea ice segment"; String long_name "Ending GEOSEG"; String source "Sea Ice ATBD"; String units "1"; } /gt2l/sea_ice_segments/geolocation/ { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geolocation/"; String Description "Contains parameters related to geolocation."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt2l/sea_ice_segments/geolocation/rgt { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geolocation/rgt"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "Reference Ground track"; String source "Sea Ice ATBD"; String units "1"; Int16 valid_max 1387; Int16 valid_min 1; } /gt2l/sea_ice_segments/geolocation/sigma_lon { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geolocation/sigma_lon"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated uncertainty for the reference photon bounce point east longitude: 1- sigma (degrees). Applies to all other photons in the group."; String long_name "longitude uncertainty"; String source "Sea Ice ATBD"; String units "degrees"; } /gt2l/sea_ice_segments/geolocation/ref_atm_delay { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geolocation/ref_atm_delay"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Atmospheric path delay, in range, for the reference photon."; String long_name "Reference Photon Atm. Path Delay"; String source "Sea Ice ATBD"; String units "meters"; } /gt2l/sea_ice_segments/geolocation/beam_azimuth { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geolocation/beam_azimuth"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "beam azimuth"; String source "Sea Ice ATBD"; String units "degrees_east"; } /gt2l/sea_ice_segments/geolocation/solar_azimuth { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geolocation/solar_azimuth"; String contentType "physicalMeansurement"; String coordinates "../delta_time ../latitude ../longitude"; String description "The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot."; String long_name "solar azimuth"; String source "Sea Ice ATBD"; String units "degrees_east"; } /gt2l/sea_ice_segments/geolocation/ref_atm_delay_derivative { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geolocation/ref_atm_delay_derivative"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Atmospheric path delay derivative with respect to ellipsoid for the reference photon, in meters per meter."; String long_name "Derivative of Atm. Path Delay"; String source "Sea Ice ATBD"; String units "meters/meter"; } /gt2l/sea_ice_segments/geolocation/sigma_lat { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geolocation/sigma_lat"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated uncertainty for the reference photon bounce point geodetic latitude: 1- sigma (degrees). Applies to all other photons in the group"; String long_name "latitude uncertainty"; String source "Sea Ice ATBD"; String units "1"; } /gt2l/sea_ice_segments/geolocation/beam_coelev { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geolocation/beam_coelev"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Co-elevation (CE) is direction from vertical of the laser beam as seen by an observer located at the laser ground spot."; String long_name "beam co-elevation"; String source "Sea Ice ATBD"; String units "degrees"; } /gt2l/sea_ice_segments/geolocation/sigma_h { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geolocation/sigma_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "height uncertainty"; String source "Sea Ice ATBD"; String units "1"; } /gt2l/sea_ice_segments/geolocation/solar_elevation { String HDF5_OBJ_FULLPATH "/gt2l/sea_ice_segments/geolocation/solar_elevation"; String contentType "physicalMeansurement"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "solar elevation"; String source "Sea Ice ATBD"; String units "degrees"; } /ancillary_data/ { String HDF5_OBJ_FULLPATH "/ancillary_data/"; String Description "Contains information ancillary to the data product. This may include product characteristics, instrument characteristics and/or processing constants."; } /ancillary_data/release { String HDF5_OBJ_FULLPATH "/ancillary_data/release"; String contentType "auxiliaryInformation"; 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."; String long_name "Release Number"; String source "Operations"; String units "1"; } /ancillary_data/end_geoseg { String HDF5_OBJ_FULLPATH "/ancillary_data/end_geoseg"; String contentType "auxiliaryInformation"; 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."; String long_name "Ending Geolocation Segment"; String source "Derived"; String units "1"; } /ancillary_data/version { String HDF5_OBJ_FULLPATH "/ancillary_data/version"; String contentType "auxiliaryInformation"; 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."; String long_name "Version"; String source "Operations"; String units "1"; } /ancillary_data/end_region { String HDF5_OBJ_FULLPATH "/ancillary_data/end_region"; String contentType "auxiliaryInformation"; 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."; String long_name "Ending Region"; String source "Derived"; String units "1"; } /ancillary_data/atlas_sdp_gps_epoch { String HDF5_OBJ_FULLPATH "/ancillary_data/atlas_sdp_gps_epoch"; String contentType "auxiliaryInformation"; 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."; String long_name "ATLAS Epoch Offset"; String source "Operations"; String units "seconds since 1980-01-06T00:00:00.000000Z"; } /ancillary_data/end_rgt { String HDF5_OBJ_FULLPATH "/ancillary_data/end_rgt"; String contentType "auxiliaryInformation"; 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."; String long_name "Ending Reference Groundtrack"; String source "Derived"; String units "1"; Int32 valid_max 1387; Int32 valid_min 1; } /ancillary_data/end_delta_time { String HDF5_OBJ_FULLPATH "/ancillary_data/end_delta_time"; String contentType "auxiliaryInformation"; 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."; String long_name "ATLAS End Time (Actual)"; String source "Derived"; String standard_name "time"; String units "seconds since 2018-01-01"; } /ancillary_data/end_orbit { String HDF5_OBJ_FULLPATH "/ancillary_data/end_orbit"; String contentType "auxiliaryInformation"; 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."; String long_name "Ending Orbit Number"; String source "Derived"; String units "1"; } /ancillary_data/start_cycle { String HDF5_OBJ_FULLPATH "/ancillary_data/start_cycle"; String contentType "auxiliaryInformation"; 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."; String long_name "Starting Cycle"; String source "Derived"; String units "1"; Int32 valid_max 99; Int32 valid_min 0; } /ancillary_data/data_end_utc { String HDF5_OBJ_FULLPATH "/ancillary_data/data_end_utc"; String contentType "auxiliaryInformation"; String source "Derived"; String description "UTC (in CCSDS-A format) of the last data point within the granule."; String long_name "End UTC Time of Granule (CCSDS-A, Actual)"; String units "1"; } /ancillary_data/control { String HDF5_OBJ_FULLPATH "/ancillary_data/control"; String contentType "auxiliaryInformation"; String units "1"; String description "PGE-specific control file used to generate this granule. To re-use, replace breaks (BR) with linefeeds."; String long_name "Control File"; String source "Operations"; } /ancillary_data/start_gpssow { String HDF5_OBJ_FULLPATH "/ancillary_data/start_gpssow"; String contentType "auxiliaryInformation"; String description "GPS seconds-of-week of the first data point in the granule."; String long_name "Start GPS SOW of Granule (Actual)"; String source "Derived"; String units "seconds"; } /ancillary_data/granule_end_utc { String HDF5_OBJ_FULLPATH "/ancillary_data/granule_end_utc"; String contentType "auxiliaryInformation"; String description "Requested end time (in UTC CCSDS-A) of this granule."; String long_name "End UTC Time of Granule (CCSDS-A, Requested)"; String source "Derived"; String units "1"; } /ancillary_data/fine_surface_finding/ { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/"; String Description "Contains ancillary parameters related to the fine surface finding algorithm."; } /ancillary_data/fine_surface_finding/tep_used_gt1_strong { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/tep_used_gt1_strong"; String contentType "auxiliaryInformation"; String description "TEP used in table generation for strong beam of ground track 1 (1 or 3)"; String long_name "TEP Table PCE1_Strong"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/fine_surface_finding/h_diff_limit { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/h_diff_limit"; String contentType "auxiliaryInformation"; String description "Maximum height difference between the two weighted Gaussian mean from the initial tracked height (units = meters)"; String long_name "Max Ht Difference"; String source "Sea Ice ATBD"; String units "meters"; } /ancillary_data/fine_surface_finding/n_specular { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/n_specular"; String contentType "auxiliaryInformation"; String description "Specular returns limits"; String long_name "number photons Specular returns"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/fine_surface_finding/tep_used_gt3_strong { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/tep_used_gt3_strong"; String contentType "auxiliaryInformation"; String description "TEP used in table generation for strong beam of ground track 3 (1 or 3)"; String long_name "TEP Table PCE3_Strong"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/fine_surface_finding/n_spec_scale { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/n_spec_scale"; String contentType "auxiliaryInformation"; 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)"; String long_name "Specular Scaling Value"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/fine_surface_finding/ub_length_strong { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/ub_length_strong"; String contentType "auxiliaryInformation"; String description "upper bound of segment length strong beam"; String long_name "upper bound segment length strong"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/fine_surface_finding/ub_oc_switch_weak { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/ub_oc_switch_weak"; String contentType "auxiliaryInformation"; String description "Upper bound of photon rate overlapping control for weak beam when overlap is turned off"; String long_name "Upper bound of overlapping control for weak beam"; String source "ATBD section 4.2.2.4"; String units "photons/shot"; } /ancillary_data/fine_surface_finding/bin_f { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/bin_f"; String contentType "auxiliaryInformation"; String description "bin size of fine histogram along track segment length"; String long_name "bin size of fine histogram"; String source "Sea Ice ATBD"; String units "meters"; } /ancillary_data/fine_surface_finding/lb_oc_switch_strong { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/lb_oc_switch_strong"; String contentType "auxiliaryInformation"; String units "photons/shot"; String description "Lower bound of photon rate overlapping control for strong beam when overlap is turned off"; String long_name "Lower bound of overlapping control for strong beam"; String source "ATBD section 4.2.2.4"; } /ancillary_data/fine_surface_finding/lb_oc_switch_weak { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/lb_oc_switch_weak"; String contentType "auxiliaryInformation"; String units "photons/shot"; String description "Lower bound of photon rate overlapping control for weak beam when overlap is turned off"; String long_name "Lower bound of overlapping control for weak beam"; String source "ATBD section 4.2.2.4"; } /ancillary_data/fine_surface_finding/tep_used_gt2_strong { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/tep_used_gt2_strong"; String contentType "auxiliaryInformation"; String description "TEP used in table generation for strong beam of ground track 2 (1 or 3)"; String long_name "TEP Table PCE2_Strong"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/fine_surface_finding/n_photon_min { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/n_photon_min"; String contentType "auxiliaryInformation"; String description "Minimum fraction of photons needed for tracking"; String long_name "Minimum number of photons"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/fine_surface_finding/n_w { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/n_w"; String contentType "auxiliaryInformation"; String description "number of standard deviations"; String long_name "number of standard deviations"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/fine_surface_finding/tep_used_gt3_weak { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/tep_used_gt3_weak"; String contentType "auxiliaryInformation"; String description "TEP used in table generation for weak beam of ground track 3 (1 or 3)"; String long_name "TEP Table PCE3_Weak"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/fine_surface_finding/delta_h_tab { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/delta_h_tab"; String contentType "auxiliaryInformation"; String description "the waveform table spacing for the height (h) dimension"; String long_name "h table spacing"; String source "Sea Ice ATBD"; String units "meters"; } /ancillary_data/fine_surface_finding/overlap_switch { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/overlap_switch"; String contentType "auxiliaryInformation"; String description "Use of overlapping height segments (1 = yes, 0 = no)"; String flag_meanings "no yes"; Int32 flag_values 0, 1; String long_name "Overlap Segments"; String source "Sea Ice ATBD"; String units "1"; Int32 valid_max 1; Int32 valid_min 0; } /ancillary_data/fine_surface_finding/lb_win_s { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/lb_win_s"; String contentType "auxiliaryInformation"; String source "Sea Ice ATBD"; String description "window (Ws) containing signal photons"; String long_name "lower bound window signal"; String units "meters"; } /ancillary_data/fine_surface_finding/tep_used_gt2_weak { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/tep_used_gt2_weak"; String contentType "auxiliaryInformation"; String description "TEP used in table generation for weak beam of ground track 2 (1 or 3)"; String long_name "TEP Table PCE2_Weak"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/fine_surface_finding/tep_used_gt1_weak { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/tep_used_gt1_weak"; String contentType "auxiliaryInformation"; String description "TEP used in table generation for weak beam of ground track 1 (1 or 3)"; String long_name "TEP Table PCE1_Weak"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/fine_surface_finding/n_s { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/n_s"; String contentType "auxiliaryInformation"; String description "photons in W_s"; String long_name "number photons in W_s"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/fine_surface_finding/ub_win_s { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/ub_win_s"; String contentType "auxiliaryInformation"; String description "window (Ws) containing signal photons"; String long_name "upper bound window signal"; String source "Sea Ice ATBD"; String units "meters"; } /ancillary_data/fine_surface_finding/ub_length_weak { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/ub_length_weak"; String contentType "auxiliaryInformation"; String description "upper bound of segment length weak beam"; String long_name "upper bound segment length weak"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/fine_surface_finding/ub_h_tab { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/ub_h_tab"; String contentType "auxiliaryInformation"; String description "the waveform upper bound for the height (h) dimension"; String long_name "upper bound of h table"; String source "Sea Ice ATBD"; String units "meters"; } /ancillary_data/fine_surface_finding/ub_oc_switch_strong { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/ub_oc_switch_strong"; String contentType "auxiliaryInformation"; String description "Upper bound of photon rate overlapping control for strong beam when overlap is turned off"; String long_name "Upper bound of overlapping control for strong beam"; String source "ATBD section 4.2.2.4"; String units "photons/shot"; } /ancillary_data/fine_surface_finding/ub_w_tab { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/ub_w_tab"; String contentType "auxiliaryInformation"; String description "the waveform upper bound for the width (w) dimension"; String long_name "upper bound of w table"; String source "Sea Ice ATBD"; String units "meters"; } /ancillary_data/fine_surface_finding/n_photon_trim { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/n_photon_trim"; String contentType "auxiliaryInformation"; String description "Minimum number of photons for trimming leading/trailing bins"; String long_name "Min Photons"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/fine_surface_finding/delta_w_tab { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/delta_w_tab"; String contentType "auxiliaryInformation"; String description "the waveform table spacing for the width (w) dimension"; String long_name "w table spacing"; String source "Sea Ice ATBD"; String units "meters"; } /ancillary_data/fine_surface_finding/lb_w_tab { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/lb_w_tab"; String contentType "auxiliaryInformation"; String description "lower bound of w table"; String long_name "lower bound of w table"; String source "Sea Ice ATBD"; String units "meters"; } /ancillary_data/fine_surface_finding/lb_h_tab { String HDF5_OBJ_FULLPATH "/ancillary_data/fine_surface_finding/lb_h_tab"; String contentType "auxiliaryInformation"; String description "lower bound of h table"; String long_name "lower bound of h table"; String source "Sea Ice ATBD"; String units "meters"; } /ancillary_data/end_cycle { String HDF5_OBJ_FULLPATH "/ancillary_data/end_cycle"; String contentType "auxiliaryInformation"; String long_name "Ending Cycle"; 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."; String source "Derived"; String units "1"; Int32 valid_max 99; Int32 valid_min 0; } /ancillary_data/sea_ice/ { String HDF5_OBJ_FULLPATH "/ancillary_data/sea_ice/"; String Description "Contains ancillary parameters related to sea ice."; } /ancillary_data/sea_ice/min_segs_count { String HDF5_OBJ_FULLPATH "/ancillary_data/sea_ice/min_segs_count"; String contentType "auxiliaryInformation"; String description "ATL07 granules with less than this number of strong beam sea ice segments will be marked as failed."; String long_name "Minimum Segments Count"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/sea_ice/proc_beam_pair1 { String HDF5_OBJ_FULLPATH "/ancillary_data/sea_ice/proc_beam_pair1"; String contentType "auxiliaryInformation"; String description "Indicates if beam pair 1 was processed."; String flag_meanings "not_processed processed"; Int32 flag_values 0, 1; String long_name "Processing Flag for Beam Pair 1"; String source "Operations"; String units "1"; Int32 valid_max 1; Int32 valid_min 0; } /ancillary_data/sea_ice/proc_beam_pair3 { String HDF5_OBJ_FULLPATH "/ancillary_data/sea_ice/proc_beam_pair3"; String contentType "auxiliaryInformation"; String description "Indicates if beam pair 3 was processed."; String flag_meanings "not_processed processed"; Int32 flag_values 0, 1; String long_name "Processing Flag for Beam Pair 3"; String source "Operations"; String units "1"; Int32 valid_max 1; Int32 valid_min 0; } /ancillary_data/sea_ice/geoseg_min { String HDF5_OBJ_FULLPATH "/ancillary_data/sea_ice/geoseg_min"; String contentType "auxiliaryInformation"; String description "Indicates the minimum segment_id to process (if specified in control)"; String long_name "Minimum Segment ID"; String source "Operations"; String units "1"; } /ancillary_data/sea_ice/proc_interval { String HDF5_OBJ_FULLPATH "/ancillary_data/sea_ice/proc_interval"; String contentType "auxiliaryInformation"; String description "The number of 20 meter segments of data processed in one chunk"; String long_name "Processing interval"; String source "Operations"; String units "1"; } /ancillary_data/sea_ice/proc_beam_pair2 { String HDF5_OBJ_FULLPATH "/ancillary_data/sea_ice/proc_beam_pair2"; String contentType "auxiliaryInformation"; String description "Indicates if beam pair 2 was processed."; String flag_meanings "not_processed processed"; Int32 flag_values 0, 1; String long_name "Processing Flag for Beam Pair 2"; String source "Operations"; String units "1"; Int32 valid_max 1; Int32 valid_min 0; } /ancillary_data/sea_ice/geoseg_max { String HDF5_OBJ_FULLPATH "/ancillary_data/sea_ice/geoseg_max"; String contentType "auxiliaryInformation"; String description "Indicates the maximum segment_id to process (if specified in control). The actual maximum processed may be greater than specified."; String long_name "Maximum Segment Id"; String source "Operations"; String units "1"; } /ancillary_data/sea_ice/region { String HDF5_OBJ_FULLPATH "/ancillary_data/sea_ice/region"; String contentType "auxiliaryInformation"; String description "The index to the geographic region covered within this granule (0=no region boundaries enforced)."; String long_name "Region Index"; String source "Operations"; String units "1"; } /ancillary_data/granule_start_utc { String HDF5_OBJ_FULLPATH "/ancillary_data/granule_start_utc"; String contentType "auxiliaryInformation"; String description "Requested start time (in UTC CCSDS-A) of this granule."; String long_name "Start UTC Time of Granule (CCSDS-A, Requested)"; String source "Derived"; String units "1"; } /ancillary_data/start_delta_time { String HDF5_OBJ_FULLPATH "/ancillary_data/start_delta_time"; String contentType "auxiliaryInformation"; 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."; String long_name "ATLAS Start Time (Actual)"; String source "Derived"; String standard_name "time"; String units "seconds since 2018-01-01"; } /ancillary_data/start_geoseg { String HDF5_OBJ_FULLPATH "/ancillary_data/start_geoseg"; String contentType "auxiliaryInformation"; 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."; String long_name "Starting Geolocation Segment"; String source "Derived"; String units "1"; } /ancillary_data/start_orbit { String HDF5_OBJ_FULLPATH "/ancillary_data/start_orbit"; String contentType "auxiliaryInformation"; 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."; String long_name "Starting Orbit Number"; String source "Derived"; String units "1"; } /ancillary_data/data_start_utc { String HDF5_OBJ_FULLPATH "/ancillary_data/data_start_utc"; String contentType "auxiliaryInformation"; String source "Derived"; String description "UTC (in CCSDS-A format) of the first data point within the granule."; String long_name "Start UTC Time of Granule (CCSDS-A, Actual)"; String units "1"; } /ancillary_data/coarse_surface_finding/ { String HDF5_OBJ_FULLPATH "/ancillary_data/coarse_surface_finding/"; String Description "Contains ancillary parameters related to the coarse surface finding algorithm."; } /ancillary_data/coarse_surface_finding/bin_c { String HDF5_OBJ_FULLPATH "/ancillary_data/coarse_surface_finding/bin_c"; String contentType "auxiliaryInformation"; String description "bin size of coarse histogram"; String long_name "bin size coarse histogram"; String source "Sea Ice ATBD"; String units "meters"; } /ancillary_data/coarse_surface_finding/coarse_ub_wins { String HDF5_OBJ_FULLPATH "/ancillary_data/coarse_surface_finding/coarse_ub_wins"; String contentType "auxiliaryInformation"; String description "Upper bound for signal photons when performing coarse tracking"; String long_name "Coarse_UpperBounds"; String source "Sea Ice ATBD"; String units "meters"; } /ancillary_data/coarse_surface_finding/th_pc { String HDF5_OBJ_FULLPATH "/ancillary_data/coarse_surface_finding/th_pc"; String contentType "auxiliaryInformation"; String description "percentage cloud cover coarse"; String long_name "threshold percentage cloud cover coarse"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/coarse_surface_finding/coarse_lb_wins { String HDF5_OBJ_FULLPATH "/ancillary_data/coarse_surface_finding/coarse_lb_wins"; String contentType "auxiliaryInformation"; String description "Lower bound for signal photons when performing coarse tracking"; String long_name "Coarse_LowerrBounds"; String source "Sea Ice ATBD"; String units "meters"; } /ancillary_data/coarse_surface_finding/l { String HDF5_OBJ_FULLPATH "/ancillary_data/coarse_surface_finding/l"; String contentType "auxiliaryInformation"; String description "along track segment length coarse"; String long_name "segment length coarse"; String source "Sea Ice ATBD"; String units "meters"; } /ancillary_data/coarse_surface_finding/th_d_bot { String HDF5_OBJ_FULLPATH "/ancillary_data/coarse_surface_finding/th_d_bot"; String contentType "auxiliaryInformation"; String source "Sea Ice ATBD"; String description "Bottom distance from mode coarse"; String long_name "Bottom threshold distance from mode coarse"; String units "meters"; } /ancillary_data/coarse_surface_finding/th_fm { String HDF5_OBJ_FULLPATH "/ancillary_data/coarse_surface_finding/th_fm"; String contentType "auxiliaryInformation"; String source "Sea Ice ATBD"; String description "fraction of histogram peak coarse"; String long_name "threshold fraction of peak coarse"; String units "1"; } /ancillary_data/coarse_surface_finding/n_ph_min { String HDF5_OBJ_FULLPATH "/ancillary_data/coarse_surface_finding/n_ph_min"; String contentType "auxiliaryInformation"; String description "Minimum number of photons required for coarse track segment"; String long_name "Minimum Number of Photons"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/coarse_surface_finding/si_conc_min { String HDF5_OBJ_FULLPATH "/ancillary_data/coarse_surface_finding/si_conc_min"; String contentType "auxiliaryInformation"; String source "Sea Ice ATBD"; String description "Minimum sea ice concentration percentage value for which to process data."; String long_name "Min SI Concentration Thresh"; String units "1"; } /ancillary_data/coarse_surface_finding/th_d_top { String HDF5_OBJ_FULLPATH "/ancillary_data/coarse_surface_finding/th_d_top"; String contentType "auxiliaryInformation"; String description "Top distance from mode coarse"; String long_name "Top threshold distance from mode coarse"; String source "Sea Ice ATBD"; String units "meters"; } /ancillary_data/coarse_surface_finding/th_tc { String HDF5_OBJ_FULLPATH "/ancillary_data/coarse_surface_finding/th_tc"; String contentType "auxiliaryInformation"; String description "height deviations from surface or adjacent strong beam"; String long_name "Threshold height deviations"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/surface_classification/ { String HDF5_OBJ_FULLPATH "/ancillary_data/surface_classification/"; String Description "Contains ancillary parameters related to the surface classification algorithm."; } /ancillary_data/surface_classification/theta_ref { String HDF5_OBJ_FULLPATH "/ancillary_data/surface_classification/theta_ref"; String contentType "auxiliaryInformation"; String description "Solar elevation normalization angle for use of normalized background rate"; String long_name "Solar elevation normalization angle"; String source "ATBD section 4.3.1.4"; String units "degrees"; } /ancillary_data/surface_classification/height_pct { String HDF5_OBJ_FULLPATH "/ancillary_data/surface_classification/height_pct"; String contentType "auxiliaryInformation"; String description "Percentile of sorted heights"; String long_name "Percentile Hts"; String source "Sea Ice ATBD"; String units "percentile"; } /ancillary_data/surface_classification/w1 { String HDF5_OBJ_FULLPATH "/ancillary_data/surface_classification/w1"; String contentType "auxiliaryInformation"; String description "max width (dark smooth lead)"; String long_name "max width (dark smooth lead)"; String source "Sea Ice ATBD"; String units "meters"; } /ancillary_data/surface_classification/beam_gain { String HDF5_OBJ_FULLPATH "/ancillary_data/surface_classification/beam_gain"; String contentType "auxiliaryInformation"; 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)"; String long_name "relative beam gain for beams 1 through 6"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/surface_classification/p3 { String HDF5_OBJ_FULLPATH "/ancillary_data/surface_classification/p3"; String contentType "auxiliaryInformation"; String description "photon rate (shadow)"; String long_name "pr (shadow)"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/surface_classification/b1 { String HDF5_OBJ_FULLPATH "/ancillary_data/surface_classification/b1"; String contentType "auxiliaryInformation"; String description "max backgr (gray ice)"; String long_name "max backgr (gray ice)"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/surface_classification/p4 { String HDF5_OBJ_FULLPATH "/ancillary_data/surface_classification/p4"; String contentType "auxiliaryInformation"; String description "photon rate (specular)"; String long_name "pr (specular)"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/surface_classification/w2 { String HDF5_OBJ_FULLPATH "/ancillary_data/surface_classification/w2"; String contentType "auxiliaryInformation"; String description "max width (dark rough lead)"; String long_name "max width (dark rough lead)"; String source "Sea Ice ATBD"; String units "meters"; } /ancillary_data/surface_classification/theta_cntl { String HDF5_OBJ_FULLPATH "/ancillary_data/surface_classification/theta_cntl"; String contentType "auxiliaryInformation"; String source "Sea Ice ATBD"; String description "Solar elevation for controlling use of background rate"; String long_name "Solar elevation for use of background rate"; String units "1"; } /ancillary_data/surface_classification/theta_nlb { String HDF5_OBJ_FULLPATH "/ancillary_data/surface_classification/theta_nlb"; String contentType "auxiliaryInformation"; String units "degrees"; String description "Solar elevation normalization lower bound for use of normalized background rate"; String long_name "Solar elevation normalization lower bound"; String source "ATBD section 4.3.1.4"; } /ancillary_data/surface_classification/p1 { String HDF5_OBJ_FULLPATH "/ancillary_data/surface_classification/p1"; String contentType "auxiliaryInformation"; String description "photon rate (clouds)"; String long_name "pr (clouds)"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/surface_classification/p2 { String HDF5_OBJ_FULLPATH "/ancillary_data/surface_classification/p2"; String contentType "auxiliaryInformation"; String description "photon rate (snow)"; String long_name "pr (snow)"; String source "Sea Ice ATBD"; String units "1"; } /ancillary_data/end_gpsweek { String HDF5_OBJ_FULLPATH "/ancillary_data/end_gpsweek"; String contentType "auxiliaryInformation"; String description "GPS week number of the last data point in the granule."; String long_name "Ending GPSWeek of Granule (Actual)"; String source "Derived"; String units "weeks from 1980-01-06"; } /ancillary_data/start_rgt { String HDF5_OBJ_FULLPATH "/ancillary_data/start_rgt"; String contentType "auxiliaryInformation"; 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."; String long_name "Starting Reference Groundtrack"; String source "Derived"; String units "1"; Int32 valid_max 1387; Int32 valid_min 1; } /ancillary_data/end_gpssow { String HDF5_OBJ_FULLPATH "/ancillary_data/end_gpssow"; String contentType "auxiliaryInformation"; String description "GPS seconds-of-week of the last data point in the granule."; String long_name "Ending GPS SOW of Granule (Actual)"; String source "Derived"; String units "seconds"; } /ancillary_data/qa_at_interval { String HDF5_OBJ_FULLPATH "/ancillary_data/qa_at_interval"; String contentType "auxiliaryInformation"; String description "Statistics time interval for along-track QA data."; String long_name "QA Along-Track Interval"; String source "control"; String units "1"; } /ancillary_data/start_region { String HDF5_OBJ_FULLPATH "/ancillary_data/start_region"; String contentType "auxiliaryInformation"; 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."; String long_name "Starting Region"; String source "Derived"; String units "1"; } /ancillary_data/start_gpsweek { String HDF5_OBJ_FULLPATH "/ancillary_data/start_gpsweek"; String contentType "auxiliaryInformation"; String description "GPS week number of the first data point in the granule."; String long_name "Start GPSWeek of Granule (Actual)"; String source "Derived"; String units "weeks from 1980-01-06"; } /gt3r/ { String HDF5_OBJ_FULLPATH "/gt3r/"; String Description "This ground contains parameters and subgroups related a specific groundtrack."; String data_rate "Each subgroup identifies its particular data rate."; String atlas_pce "pce1"; String atlas_beam_type "strong"; String groundtrack_id "gt3r"; String atmosphere_profile "profile_3"; String atlas_spot_number "1"; String sc_orientation "Forward"; } /gt3r/sea_ice_segments/ { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/"; String Description "Top group for sea ice segments as computed by the ATBD aglorithm"; String data_rate "Data within this group are stored at the variable segment rate."; } /gt3r/sea_ice_segments/heights/ { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/heights/"; String 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."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt3r/sea_ice_segments/heights/height_segment_fit_quality_flag { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/heights/height_segment_fit_quality_flag"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String flag_meanings "invalid best high med low poor"; Int16 flag_values -1, 1, 2, 3, 4, 5; String long_name "height Quality Flag"; String source "ATBD, section 4.2.4.2"; String units "1"; Int16 valid_max 5; Int16 valid_min -1; } /gt3r/sea_ice_segments/heights/height_segment_length_seg { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/heights/height_segment_length_seg"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "along-track length of segment containing n_photons_actual"; String long_name "length of segment"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3r/sea_ice_segments/heights/height_segment_asr_calc { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/heights/height_segment_asr_calc"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Computed apparent surface reflectance for the sea ice segment."; String long_name "Calculated Apparent Surface Reflectivity"; String source "Sea Ice ATBD"; String units "1"; } /gt3r/sea_ice_segments/heights/height_segment_quality { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/heights/height_segment_quality"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Height segment quality flag, 1 is good quality, 0 is bad depending on fit, wguassian, or layer flag"; String flag_meanings "bad_quality good_quality"; Int16 flag_values 0, 1; String long_name "Height Segment Quality Flag"; String source "ATBD, section 4.2.4"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt3r/sea_ice_segments/heights/height_segment_n_pulse_seg { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/heights/height_segment_n_pulse_seg"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "number of laser pulses"; String long_name "number of laser pulses"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt3r/sea_ice_segments/heights/across_track_distance { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/heights/across_track_distance"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Across track distance of photons averaged over the sea ice height segment."; String long_name "Across Track Distance"; String source "ATBD, section 4.2.4"; String units "meters"; } /gt3r/sea_ice_segments/heights/height_segment_htcorr_skew { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/heights/height_segment_htcorr_skew"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "height corection for skew"; String long_name "Height Correction for Skew"; String source "ATBD, section 4.2.6"; String units "meters"; } /gt3r/sea_ice_segments/heights/height_segment_ssh_flag { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/heights/height_segment_ssh_flag"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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"; String flag_meanings "sea_ice sea_surface"; Int16 flag_values 0, 1; String long_name "Sea Surface Flag"; String source "ATBD, section 4.3"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt3r/sea_ice_segments/heights/height_segment_height { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/heights/height_segment_height"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean height from along-track segment fit detremined by the sea ice algorithm"; String long_name "height of segment surface"; String source "ATBD, section 4.2.2.4"; String units "meters"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; } /gt3r/sea_ice_segments/heights/height_segment_type { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/heights/height_segment_type"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Value that indicates segment surface type as sea ice or different types of sea surface. 0=cloud covered: rsurf"; 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"; Int16 flag_values 0, 1, 2, 3, 4, 5, 6, 7, 8, 9; String long_name "Segment surface type"; String source "ATBD, section 4.3"; String units "1"; Int16 valid_max 9; Int16 valid_min 0; } /gt3r/sea_ice_segments/heights/height_segment_confidence { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/heights/height_segment_confidence"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Confidence level in the surface height estimate based on the number of photons; the background noise rate; and the error analysis"; String long_name "Surface height confidence"; String source "ATBD, section 4.2.4.2"; String units "1"; } /gt3r/sea_ice_segments/heights/height_segment_surface_error_est { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/heights/height_segment_surface_error_est"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Error estimate of the surface height"; String long_name "h surface error est"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3r/sea_ice_segments/heights/height_segment_w_gaussian { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/heights/height_segment_w_gaussian"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "width of best fit gaussian"; String long_name "width of best fit gaussian"; String source "ATBD, section 4.2.4"; String units "meters"; } /gt3r/sea_ice_segments/heights/height_segment_rms { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/heights/height_segment_rms"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "RMS difference between sea ice modeled and observed photon height distribution"; String long_name "height rms"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3r/sea_ice_segments/height_segment_id { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/height_segment_id"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Identifier of each height segment"; String long_name "Identifier of each height segment"; String source "ATBD, section 5.2"; String units "1"; } /gt3r/sea_ice_segments/seg_dist_x { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/seg_dist_x"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Along-track distance from the equator crossing to the segment center."; String long_name "Along track distance"; String source "Sea Ice ATBD"; String units "meters"; } /gt3r/sea_ice_segments/longitude { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/longitude"; String contentType "referenceInformation"; String coordinates "delta_time latitude"; String description "Longitude, WGS84, East=+,Lon of segment center"; String long_name "Longitude"; String source "ATBD, section 4.4"; String standard_name "longitude"; String units "degrees_east"; Float64 valid_max 180.; Float64 valid_min -180.; } /gt3r/sea_ice_segments/latitude { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/latitude"; String contentType "referenceInformation"; String coordinates "delta_time longitude"; String description "Latitude, WGS84, North=+, Lat of segment center"; String long_name "Latitude"; String source "ATBD, section 4.4"; String standard_name "latitude"; String units "degrees_north"; Float64 valid_max 90.; Float64 valid_min -90.; } /gt3r/sea_ice_segments/geophysical/ { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geophysical/"; String Description "Contains geophysical parameters and corrections used to correct photon heights for geophysical effects, such as tides."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt3r/sea_ice_segments/geophysical/height_segment_t2m { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geophysical/height_segment_t2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Temperature at 2m above the displacement height (K)"; String long_name "temperature_at_2m"; String source "ATL09"; String standard_name "temperature"; String units "K"; } /gt3r/sea_ice_segments/geophysical/height_segment_dac { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geophysical/height_segment_dac"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect."; String long_name "Dynamic Atmosphere Correction"; String source "Sea Ice ATBD"; String units "meters"; } /gt3r/sea_ice_segments/geophysical/height_segment_ps { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geophysical/height_segment_ps"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Sea Level Pressure (Pa)"; String long_name "sea level pressure"; String source "ATL09"; String standard_name "pressure"; String units "Pa"; } /gt3r/sea_ice_segments/geophysical/height_segment_ib { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geophysical/height_segment_ib"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Inverted barometer effect calculated from surface pressure"; String long_name "Inverted barometer effect"; String source "ATBD, section 4.2"; String units "meters"; } /gt3r/sea_ice_segments/geophysical/height_segment_load { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geophysical/height_segment_load"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Load Tide - Local displacement due to Ocean Loading (-6 to 0 cm)."; String long_name "Load Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt3r/sea_ice_segments/geophysical/height_segment_geoid { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geophysical/height_segment_geoid"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Geoid height above WGS-84 reference ellipsoid (range -107 to 86m), based on the EGM2008 model."; String long_name "EGM2008 Geoid"; String source "Sea Ice ATBD"; String units "meters"; } /gt3r/sea_ice_segments/geophysical/height_segment_ocean { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geophysical/height_segment_ocean"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Ocean Tides including diurnal and semi-diurnal (harmonic analysis), and longer period tides (dynamic and self-consistent equilibrium)"; String long_name "Ocean Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt3r/sea_ice_segments/geophysical/height_segment_v2m { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geophysical/height_segment_v2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Northward wind at 2m above the displacement height (m/s-1)"; String long_name "Northward_wind_at_2m"; String source "ATL09"; String standard_name "northward_wind"; String units "m s-1"; } /gt3r/sea_ice_segments/geophysical/height_segment_mss { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geophysical/height_segment_mss"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean sea surface height above WGS-84 reference ellipsoid (range: -105 to 87m), based on the DTU13 model."; String long_name "DTU13 Mean Sea Surface"; String source "Sea Ice ATBD"; String units "meters"; } /gt3r/sea_ice_segments/geophysical/height_segment_u2m { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geophysical/height_segment_u2m"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Eastward wind at 2m above the displacement height (m/s-1)"; String long_name "Eastward_wind_at_2m"; String source "ATL09"; String standard_name "eastward_wind"; String units "m s-1"; } /gt3r/sea_ice_segments/geophysical/height_segment_lpe { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geophysical/height_segment_lpe"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Long period equilibrium tide self-consistent with ocean tide model (+-0.04m). (dependent only on time and latitude)"; String long_name "Equilibrium Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt3r/sea_ice_segments/geophysical/height_segment_earth { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geophysical/height_segment_earth"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Solid Earth Tide"; String long_name "Earth Tide"; String source "Sea Ice ATBD"; String units "meters"; } /gt3r/sea_ice_segments/geophysical/height_segment_pole { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geophysical/height_segment_pole"; String coordinates "../delta_time ../latitude ../longitude"; String description "Pole Tide -Rotational deformation due to polar motion (-1.5 to 1.5 cm)."; String long_name "Pole Tide"; String source "Sea Ice ATBD"; String units "meters"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; } /gt3r/sea_ice_segments/geoseg_beg { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geoseg_beg"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Geolocation segment (geoseg) ID associated with the first photon used in this sea ice segment"; String long_name "Beginning GEOSEG"; String source "Sea Ice ATBD"; String units "1"; } /gt3r/sea_ice_segments/delta_time { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/delta_time"; String contentType "physicalMeasurement"; String coordinates "latitude longitude"; 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."; String long_name "Elapsed GPS seconds"; String source "telemetry"; String standard_name "time"; String units "seconds since 2018-01-01"; String CLASS "DIMENSION_SCALE"; String NAME "gt3r/sea_ice_segments/delta_time"; } /gt3r/sea_ice_segments/stats/ { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/"; String Description "Contains parameters related to quality and corrections on the sea ice height paramters"; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt3r/sea_ice_segments/stats/msw_flag { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/msw_flag"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; 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."; 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"; Int16 flag_values -1, 0, 1, 2, 3, 4, 5; String long_name "Multiple Scattering Warning Flag"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 5; Int16 valid_min -1; } /gt3r/sea_ice_segments/stats/hist_median_h { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/hist_median_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Median of the n_fit_photons heights"; String long_name "trimmed photon heights median"; String source "ATBD, section 4.2.3.1"; String units "meters"; } /gt3r/sea_ice_segments/stats/height_filter_min { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/height_filter_min"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height minimum used in the ssh height filter"; String long_name "Height Filter Min"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt3r/sea_ice_segments/stats/cloud_flag_atm { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/cloud_flag_atm"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of layers found from the backscatter profile using the DDA layer finder."; String long_name "Cloud Flag Atm"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 10; Int16 valid_min 0; } /gt3r/sea_ice_segments/stats/fpb_avg_dt { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/fpb_avg_dt"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction average dead time"; String long_name "fpb correction average deadtime"; String source "Sea Ice ATBD"; String units "ns"; } /gt3r/sea_ice_segments/stats/ds_si_hist_bins { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/ds_si_hist_bins"; String CLASS "DIMENSION_SCALE"; String NAME "ds_si_hist_bins"; String contentType "auxiliaryInformation"; 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."; String long_name "Sea Ice Histogram Bins Dimension Scale"; String source "SeaIce ATBD"; String units "1"; } /gt3r/sea_ice_segments/stats/fpb_strength { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/fpb_strength"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction strength"; String long_name "fpb correction strength"; String source "Sea Ice ATBD"; String units "photons/shot"; } /gt3r/sea_ice_segments/stats/bsnow_con { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/bsnow_con"; Int16 _FillValue 127; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Blowing snow confidence"; String long_name "Blowing snow confidence"; String source "ATL09"; String units "1"; } /gt3r/sea_ice_segments/stats/layer_flag { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/layer_flag"; String contentType "qualityInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String flag_meanings "likely_clear likely_cloudy"; Int16 flag_values 0, 1; String long_name "Consolidated cloud flag"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 1; Int16 valid_min 0; } /gt3r/sea_ice_segments/stats/hist_photon_bin_size { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/hist_photon_bin_size"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "bin size of photon height histogram"; String long_name "height histogram bin size"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3r/sea_ice_segments/stats/backgr_calc { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/backgr_calc"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Calculated background count rate based on sun angle, surface slope, unit reflectance"; String long_name "background count rate calculated"; String source "ATBD, section 4.2.3"; String units "hz"; } /gt3r/sea_ice_segments/stats/fpb_corr { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/fpb_corr"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated first-photon bias(fpb) correction to mean segment height"; String long_name "first photon bias correction"; String source "Sea Ice ATBD"; String units "meters"; } /gt3r/sea_ice_segments/stats/bsnow_h { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/bsnow_h"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "Blowing snow layer top height"; String long_name "Blowing snow top h"; String source "ATL09"; String units "meters"; } /gt3r/sea_ice_segments/stats/hist_photon_bottom { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/hist_photon_bottom"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "lower bound of height histogram"; String long_name "height histogram minimum"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3r/sea_ice_segments/stats/background_r_norm { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/background_r_norm"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background rate normalized to a fixed solar elevation angle"; String long_name "Normalized background (50-shot)"; String source "ATBD section 4.3.1.3"; String units "hz"; } /gt3r/sea_ice_segments/stats/exmax_mean_2 { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/exmax_mean_2"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mean 2"; String long_name "Exmax Mean 2"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt3r/sea_ice_segments/stats/background_int_height { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/background_int_height"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "The height of the altimetric range window after subtracting the height span of the signal photon events in the 50-shot span"; String long_name "Height of column used in background calculation"; String source "ATBD, section 7.3"; String units "meters"; } /gt3r/sea_ice_segments/stats/n_photons_actual { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/n_photons_actual"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons gathered"; String long_name "Number of photons found for the segment"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt3r/sea_ice_segments/stats/ice_conc { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/ice_conc"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "sea ice concentration"; String long_name "sea ice concentration"; String source "ATBD, section 3.1.4"; String units "1"; } /gt3r/sea_ice_segments/stats/exmax_stdev_2 { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/exmax_stdev_2"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height standard deviation 2"; String long_name "Exmax Stdev 2"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt3r/sea_ice_segments/stats/cloud_flag_asr { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/cloud_flag_asr"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; 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"; 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"; Int16 flag_values 0, 1, 2, 3, 4, 5, 6; String long_name "Cloud Flag ASR"; String source "Atmosphere ATBD"; String units "1"; Int16 valid_max 6; Int16 valid_min 0; } /gt3r/sea_ice_segments/stats/exmax_stdev_1 { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/exmax_stdev_1"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height standard deviation 1"; String long_name "Exmax Stdev 1"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt3r/sea_ice_segments/stats/fpb_corr_width { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/fpb_corr_width"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "FPB correction width"; String long_name "fpb correction width"; String source "Sea Ice ATBD"; String units "ns"; } /gt3r/sea_ice_segments/stats/height_coarse_stdev { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/height_coarse_stdev"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height standard deviation of coarse tracker"; String long_name "Coarse Height Sdev"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt3r/sea_ice_segments/stats/height_filter_05 { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/height_filter_05"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height fifth percentile used in the ssh height filter"; String long_name "Height Filter 5th Percentile"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt3r/sea_ice_segments/stats/n_photons_used { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/n_photons_used"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons in the trimmed histogram."; String long_name "Number of photons used for fit"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt3r/sea_ice_segments/stats/backgr_r_200 { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/backgr_r_200"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background count rate, averaged over the segment based on ATLAS 50 pulse counts"; String long_name "Background rate 200 hz"; String source "ATL09"; String units "hz"; } /gt3r/sea_ice_segments/stats/hist_photon_top { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/hist_photon_top"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "upper bound of height histogram"; String long_name "height histogram maximum"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3r/sea_ice_segments/stats/hist_w { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/hist_w"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Segment histogram width estimate"; String long_name "Segment histogram width estimate"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3r/sea_ice_segments/stats/hist_mean_h { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/hist_mean_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Mean of the n_fit_photons heights"; String long_name "photon heights mean"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3r/sea_ice_segments/stats/height_coarse_mn { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/height_coarse_mn"; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "height mean of coarse tracker"; String long_name "Coarse Track Height Mean"; String source "sea ice ATBD , sect 4.2.1.2"; String units "meters"; } /gt3r/sea_ice_segments/stats/exmax_mean_1 { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/exmax_mean_1"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mean 1"; String long_name "Exmax Mean 1"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt3r/sea_ice_segments/stats/hist_photon_heights { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/hist_photon_heights"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Histogram of the n_fit_photons heights"; String long_name "photon heights histogram"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt3r/sea_ice_segments/stats/trim_height_top { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/trim_height_top"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "maximum height of trimmed photons used in the surface calculation procedure"; String long_name "maximum height of trimmed photons"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3r/sea_ice_segments/stats/exmax_mix { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/exmax_mix"; Float32 _FillValue 3.402823466e+38; String contentType "modelResult"; String coordinates "../delta_time ../latitude ../longitude"; String description "exmax height mix ratio"; String long_name "Exmax Mix"; String source "sea ice ATBD Appendix E"; String units "meters"; } /gt3r/sea_ice_segments/stats/asr_25 { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/asr_25"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Apparent surface reflectance at 25 hz, averaged to the sea ice segment."; String long_name "Apparent Surface Reflectance 25hz"; String source "Sea Ice ATBD"; String units "1"; } /gt3r/sea_ice_segments/stats/photon_rate { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/photon_rate"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "photon count rate, averaged over segment"; String long_name "photon rate"; String source "ATBD, section 4.2.2.4"; String units "photons/shot"; } /gt3r/sea_ice_segments/stats/trim_height_bottom { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/trim_height_bottom"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "minimum height of trimmed photons used in the surface calculation procedure"; String long_name "minimum height of trimmed photons"; String source "ATBD, section 4.2.2.4"; String units "meters"; } /gt3r/sea_ice_segments/stats/n_photons_define { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/n_photons_define"; Int16 _FillValue -1; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Number of photons to gather."; String long_name "Number of photons defining the segment"; String source "ATBD, section 4.2.2.4"; String units "1"; } /gt3r/sea_ice_segments/stats/backgr_r_25 { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/stats/backgr_r_25"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Background count rate, averaged over the segment based on 25 hz atmosphere"; String long_name "Background rate 25hz"; String source "ATL09"; String units "hz"; } /gt3r/sea_ice_segments/geoseg_end { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geoseg_end"; String contentType "referenceInformation"; String coordinates "delta_time latitude longitude"; String description "Geolocation segment (geoseg) ID associated with the last photon used in this sea ice segment"; String long_name "Ending GEOSEG"; String source "Sea Ice ATBD"; String units "1"; } /gt3r/sea_ice_segments/geolocation/ { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geolocation/"; String Description "Contains parameters related to geolocation."; String data_rate "Data within this group are stored at the sea_ice_height segment rate."; } /gt3r/sea_ice_segments/geolocation/rgt { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geolocation/rgt"; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "Reference Ground track"; String source "Sea Ice ATBD"; String units "1"; Int16 valid_max 1387; Int16 valid_min 1; } /gt3r/sea_ice_segments/geolocation/sigma_lon { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geolocation/sigma_lon"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated uncertainty for the reference photon bounce point east longitude: 1- sigma (degrees). Applies to all other photons in the group."; String long_name "longitude uncertainty"; String source "Sea Ice ATBD"; String units "degrees"; } /gt3r/sea_ice_segments/geolocation/ref_atm_delay { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geolocation/ref_atm_delay"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Atmospheric path delay, in range, for the reference photon."; String long_name "Reference Photon Atm. Path Delay"; String source "Sea Ice ATBD"; String units "meters"; } /gt3r/sea_ice_segments/geolocation/beam_azimuth { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geolocation/beam_azimuth"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "beam azimuth"; String source "Sea Ice ATBD"; String units "degrees_east"; } /gt3r/sea_ice_segments/geolocation/solar_azimuth { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geolocation/solar_azimuth"; String contentType "physicalMeansurement"; String coordinates "../delta_time ../latitude ../longitude"; String description "The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot."; String long_name "solar azimuth"; String source "Sea Ice ATBD"; String units "degrees_east"; } /gt3r/sea_ice_segments/geolocation/ref_atm_delay_derivative { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geolocation/ref_atm_delay_derivative"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Atmospheric path delay derivative with respect to ellipsoid for the reference photon, in meters per meter."; String long_name "Derivative of Atm. Path Delay"; String source "Sea Ice ATBD"; String units "meters/meter"; } /gt3r/sea_ice_segments/geolocation/sigma_lat { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geolocation/sigma_lat"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Estimated uncertainty for the reference photon bounce point geodetic latitude: 1- sigma (degrees). Applies to all other photons in the group"; String long_name "latitude uncertainty"; String source "Sea Ice ATBD"; String units "1"; } /gt3r/sea_ice_segments/geolocation/beam_coelev { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geolocation/beam_coelev"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; String description "Co-elevation (CE) is direction from vertical of the laser beam as seen by an observer located at the laser ground spot."; String long_name "beam co-elevation"; String source "Sea Ice ATBD"; String units "degrees"; } /gt3r/sea_ice_segments/geolocation/sigma_h { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geolocation/sigma_h"; Float32 _FillValue 3.402823466e+38; String contentType "referenceInformation"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "height uncertainty"; String source "Sea Ice ATBD"; String units "1"; } /gt3r/sea_ice_segments/geolocation/solar_elevation { String HDF5_OBJ_FULLPATH "/gt3r/sea_ice_segments/geolocation/solar_elevation"; String contentType "physicalMeansurement"; String coordinates "../delta_time ../latitude ../longitude"; 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."; String long_name "solar elevation"; String source "Sea Ice ATBD"; String units "degrees"; } }