Attributes { HDF5_ROOT_GROUP { orbit_info { String Dataset "rgt", "bounding_polygon_lat1", "cycle_number", "crossing_time", "lan", "sc_orient_time", "orbit_number", "bounding_polygon_lon1", "sc_orient"; } METADATA { AcquisitionInformation { lidar { } lidarDocument { } platform { } platformDocument { } } ProductSpecificationDocument { } SeriesIdentification { } DatasetIdentification { } Extent { } String Dataset "iso_19139_dataset_xml", "iso_19139_series_xml"; QADatasetIdentification { } Lineage { Control { } ANC28 { } ANC14 { } ANC06-02 { } ANC06-03 { } ANC25-08 { } ANC46 { } ANC47 { } ANC33 { } ANC18 { } ANC38-08 { } ATL03 { } ATL09 { } ANC06-01 { } ANC26-08 { } ANC19 { } ANC36-08 { } } ProcessStep { Browse { } Metadata { } PGE { } QA { } } } String Dataset "ds_metrics", "ds_surf_type", "ds_geosegments"; gt1r { land_segments { String Dataset "segment_watermask", "delta_time_end", "latitude_20m", "rgt", "dem_flag", "msw_flag", "permafrost_prob", "cloud_flag_atm", "snr", "sigma_across", "layer_flag", "segment_snowcover", "beam_azimuth", "solar_azimuth", "psf_flag", "longitude", "latitude", "segment_id_end", "longitude_20m", "surf_type", "brightness_flag", "segment_landcover", "ph_removal_flag", "asr", "sigma_atlas_land", "segment_id_beg", "sigma_along", "dem_h", "beam_coelev", "sat_flag", "sigma_topo", "night_flag", "delta_time_beg", "sigma_h", "last_seg_extend", "column_od_asr", "atlas_pa", "ph_ndx_beg", "solar_elevation", "delta_time", "cloud_fold_flag", "n_seg_ph", "terrain_flg", "urban_flag", "permafrost_alt", "dem_removal_flag", "h_dif_ref"; canopy { String Dataset "h_canopy", "canopy_rh_conf", "h_median_canopy_abs", "h_min_canopy", "h_mean_canopy_abs", "h_median_canopy", "h_canopy_abs", "toc_roughness", "h_min_canopy_abs", "h_dif_canopy", "h_canopy_quad", "h_canopy_20m", "n_ca_photons", "photon_rate_can", "centroid_height", "canopy_h_metrics_abs", "can_noise", "h_mean_canopy", "subset_can_flag", "canopy_h_metrics", "n_toc_photons", "h_max_canopy_abs", "h_canopy_uncertainty", "photon_rate_can_nr", "can_quality_score", "canopy_openness", "h_max_canopy", "segment_cover"; } terrain { String Dataset "h_te_uncertainty", "h_te_mean", "h_te_min", "photon_rate_te", "h_te_interp", "h_te_max", "h_te_rh25", "h_te_skew", "h_te_best_fit_20m", "h_te_median", "h_te_best_fit", "h_te_std", "terrain_slope", "subset_te_flag", "n_te_photons", "h_te_mode", "te_quality_score"; } } signal_photons { String Dataset "classed_pc_flag", "classed_pc_indx", "ph_h", "d_flag", "delta_time", "ph_segment_id"; } } gt2r { land_segments { String Dataset "segment_watermask", "delta_time_end", "latitude_20m", "rgt", "dem_flag", "msw_flag", "permafrost_prob", "cloud_flag_atm", "snr", "sigma_across", "layer_flag", "segment_snowcover", "beam_azimuth", "solar_azimuth", "psf_flag", "longitude", "latitude", "segment_id_end", "longitude_20m", "surf_type", "brightness_flag", "segment_landcover", "ph_removal_flag", "asr", "sigma_atlas_land", "segment_id_beg", "sigma_along", "dem_h", "beam_coelev", "sat_flag", "sigma_topo", "night_flag", "delta_time_beg", "sigma_h", "last_seg_extend", "column_od_asr", "atlas_pa", "ph_ndx_beg", "solar_elevation", "delta_time", "cloud_fold_flag", "n_seg_ph", "terrain_flg", "urban_flag", "permafrost_alt", "dem_removal_flag", "h_dif_ref"; canopy { String Dataset "h_canopy", "canopy_rh_conf", "h_median_canopy_abs", "h_min_canopy", "h_mean_canopy_abs", "h_median_canopy", "h_canopy_abs", "toc_roughness", "h_min_canopy_abs", "h_dif_canopy", "h_canopy_quad", "h_canopy_20m", "n_ca_photons", "photon_rate_can", "centroid_height", "canopy_h_metrics_abs", "can_noise", "h_mean_canopy", "subset_can_flag", "canopy_h_metrics", "n_toc_photons", "h_max_canopy_abs", "h_canopy_uncertainty", "photon_rate_can_nr", "can_quality_score", "canopy_openness", "h_max_canopy", "segment_cover"; } terrain { String Dataset "h_te_uncertainty", "h_te_mean", "h_te_min", "photon_rate_te", "h_te_interp", "h_te_max", "h_te_rh25", "h_te_skew", "h_te_best_fit_20m", "h_te_median", "h_te_best_fit", "h_te_std", "terrain_slope", "subset_te_flag", "n_te_photons", "h_te_mode", "te_quality_score"; } } signal_photons { String Dataset "classed_pc_flag", "classed_pc_indx", "ph_h", "d_flag", "delta_time", "ph_segment_id"; } } gt1l { land_segments { String Dataset "segment_watermask", "delta_time_end", "latitude_20m", "rgt", "dem_flag", "msw_flag", "permafrost_prob", "cloud_flag_atm", "snr", "sigma_across", "layer_flag", "segment_snowcover", "beam_azimuth", "solar_azimuth", "psf_flag", "longitude", "latitude", "segment_id_end", "longitude_20m", "surf_type", "brightness_flag", "segment_landcover", "ph_removal_flag", "asr", "sigma_atlas_land", "segment_id_beg", "sigma_along", "dem_h", "beam_coelev", "sat_flag", "sigma_topo", "night_flag", "delta_time_beg", "sigma_h", "last_seg_extend", "column_od_asr", "atlas_pa", "ph_ndx_beg", "solar_elevation", "delta_time", "cloud_fold_flag", "n_seg_ph", "terrain_flg", "urban_flag", "permafrost_alt", "dem_removal_flag", "h_dif_ref"; canopy { String Dataset "h_canopy", "canopy_rh_conf", "h_median_canopy_abs", "h_min_canopy", "h_mean_canopy_abs", "h_median_canopy", "h_canopy_abs", "toc_roughness", "h_min_canopy_abs", "h_dif_canopy", "h_canopy_quad", "h_canopy_20m", "n_ca_photons", "photon_rate_can", "centroid_height", "canopy_h_metrics_abs", "can_noise", "h_mean_canopy", "subset_can_flag", "canopy_h_metrics", "n_toc_photons", "h_max_canopy_abs", "h_canopy_uncertainty", "photon_rate_can_nr", "can_quality_score", "canopy_openness", "h_max_canopy", "segment_cover"; } terrain { String Dataset "h_te_uncertainty", "h_te_mean", "h_te_min", "photon_rate_te", "h_te_interp", "h_te_max", "h_te_rh25", "h_te_skew", "h_te_best_fit_20m", "h_te_median", "h_te_best_fit", "h_te_std", "terrain_slope", "subset_te_flag", "n_te_photons", "h_te_mode", "te_quality_score"; } } signal_photons { String Dataset "classed_pc_flag", "classed_pc_indx", "ph_h", "d_flag", "delta_time", "ph_segment_id"; } } quality_assessment { String Dataset "qa_granule_fail_reason", "qa_granule_pass_fail"; } gt3l { land_segments { String Dataset "segment_watermask", "delta_time_end", "latitude_20m", "rgt", "dem_flag", "msw_flag", "permafrost_prob", "cloud_flag_atm", "snr", "sigma_across", "layer_flag", "segment_snowcover", "beam_azimuth", "solar_azimuth", "psf_flag", "longitude", "latitude", "segment_id_end", "longitude_20m", "surf_type", "brightness_flag", "segment_landcover", "ph_removal_flag", "asr", "sigma_atlas_land", "segment_id_beg", "sigma_along", "dem_h", "beam_coelev", "sat_flag", "sigma_topo", "night_flag", "delta_time_beg", "sigma_h", "last_seg_extend", "column_od_asr", "atlas_pa", "ph_ndx_beg", "solar_elevation", "delta_time", "cloud_fold_flag", "n_seg_ph", "terrain_flg", "urban_flag", "permafrost_alt", "dem_removal_flag", "h_dif_ref"; canopy { String Dataset "h_canopy", "canopy_rh_conf", "h_median_canopy_abs", "h_min_canopy", "h_mean_canopy_abs", "h_median_canopy", "h_canopy_abs", "toc_roughness", "h_min_canopy_abs", "h_dif_canopy", "h_canopy_quad", "h_canopy_20m", "n_ca_photons", "photon_rate_can", "centroid_height", "canopy_h_metrics_abs", "can_noise", "h_mean_canopy", "subset_can_flag", "canopy_h_metrics", "n_toc_photons", "h_max_canopy_abs", "h_canopy_uncertainty", "photon_rate_can_nr", "can_quality_score", "canopy_openness", "h_max_canopy", "segment_cover"; } terrain { String Dataset "h_te_uncertainty", "h_te_mean", "h_te_min", "photon_rate_te", "h_te_interp", "h_te_max", "h_te_rh25", "h_te_skew", "h_te_best_fit_20m", "h_te_median", "h_te_best_fit", "h_te_std", "terrain_slope", "subset_te_flag", "n_te_photons", "h_te_mode", "te_quality_score"; } } signal_photons { String Dataset "classed_pc_flag", "classed_pc_indx", "ph_h", "d_flag", "delta_time", "ph_segment_id"; } } gt2l { land_segments { String Dataset "segment_watermask", "delta_time_end", "latitude_20m", "rgt", "dem_flag", "msw_flag", "permafrost_prob", "cloud_flag_atm", "snr", "sigma_across", "layer_flag", "segment_snowcover", "beam_azimuth", "solar_azimuth", "psf_flag", "longitude", "latitude", "segment_id_end", "longitude_20m", "surf_type", "brightness_flag", "segment_landcover", "ph_removal_flag", "asr", "sigma_atlas_land", "segment_id_beg", "sigma_along", "dem_h", "beam_coelev", "sat_flag", "sigma_topo", "night_flag", "delta_time_beg", "sigma_h", "last_seg_extend", "column_od_asr", "atlas_pa", "ph_ndx_beg", "solar_elevation", "delta_time", "cloud_fold_flag", "n_seg_ph", "terrain_flg", "urban_flag", "permafrost_alt", "dem_removal_flag", "h_dif_ref"; canopy { String Dataset "h_canopy", "canopy_rh_conf", "h_median_canopy_abs", "h_min_canopy", "h_mean_canopy_abs", "h_median_canopy", "h_canopy_abs", "toc_roughness", "h_min_canopy_abs", "h_dif_canopy", "h_canopy_quad", "h_canopy_20m", "n_ca_photons", "photon_rate_can", "centroid_height", "canopy_h_metrics_abs", "can_noise", "h_mean_canopy", "subset_can_flag", "canopy_h_metrics", "n_toc_photons", "h_max_canopy_abs", "h_canopy_uncertainty", "photon_rate_can_nr", "can_quality_score", "canopy_openness", "h_max_canopy", "segment_cover"; } terrain { String Dataset "h_te_uncertainty", "h_te_mean", "h_te_min", "photon_rate_te", "h_te_interp", "h_te_max", "h_te_rh25", "h_te_skew", "h_te_best_fit_20m", "h_te_median", "h_te_best_fit", "h_te_std", "terrain_slope", "subset_te_flag", "n_te_photons", "h_te_mode", "te_quality_score"; } } signal_photons { String Dataset "classed_pc_flag", "classed_pc_indx", "ph_h", "d_flag", "delta_time", "ph_segment_id"; } } 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"; land { String Dataset "stat20m_thresh", "ca_class", "skill_solarang_can_penalty_2", "canopy_flag_switch", "skill_cldfold_can_penalty", "skill_demremov_can_penalty", "skill_solarang_thrsh_te_1", "skill_mswflag_can_penalty", "up_toc_bnd", "skill_radmtry_thrsh_te_1", "fnlgnd_filter_switch", "skill_demremov_te_penalty", "psf", "dem_removal_percent_limit", "atl08_region", "can_noise_thresh", "skill_radmtry_thrsh_te_2", "relief_hbot", "dem_filter_switch", "relief_htop", "dseg_buf", "night_thresh", "h_canopy_perc", "up_filt_bnd", "lw_filt_bnd", "canopy20m_thresh", "skill_demremov_can_thrsh", "skill_mswflag_te_penalty", "skill_od_thrsh_can_2", "ph_removal_percent_limit", "canopy_seg", "max_try", "skill_radmtry_te_penalty_1", "bin_size_n", "skill_od_can_penalty_2", "lw_gnd_bnd", "del_mu", "skill_telemratio_can_thrsh", "yapc_switch", "lw_toc_cut", "class_thresh", "skill_od_te_penalty_1", "skill_od_can_penalty_1", "lseg_buf", "lw_toc_bnd", "up_toc_cut", "gnd_stat_thresh", "iter_max", "skill_cldfold_te_penalty", "skill_mswflag_te_thrsh", "skill_cldfold_can_thrsh", "gthresh_factor", "skill_demremov_te_thrsh", "skill_solarang_te_penalty_2", "skill_telemratio_te_thrsh", "bright_thresh", "dseg", "skill_solarang_can_penalty_1", "bin_size_h", "up_gnd_bnd", "skill_solarang_thrsh_can_2", "min_nphs", "tc_thresh", "skill_solarang_te_penalty_1", "te_class", "toc_class", "iter_gnd", "max_atl03files", "noise_class", "skill_od_thrsh_can_1", "terrain20m_thresh", "skill_cldfold_te_thrsh", "skill_snr_can_thrsh", "outlier_filter_switch", "dragann_switch", "skill_telemratio_can_penalty", "proc_geoseg", "skill_solarang_thrsh_can_1", "can_stat_thresh", "lseg", "max_atl09files", "skill_radmtry_thrsh_total_2", "skill_od_thrsh_te_1", "skill_radmtry_te_penalty_2", "skill_solarang_thrsh_te_2", "skill_snr_te_penalty", "ref_dem_limit", "skill_telemratio_te_penalty", "skill_od_te_penalty_2", "skill_snr_can_penalty", "max_peaks", "skill_weakbeam_te_penalty", "skill_snr_te_thrsh", "stat_thresh", "skill_radmtry_total_penalty_1", "sig_rsq_search", "skill_weakbeam_can_penalty", "skill_radmtry_thrsh_total_1", "del_amp", "sseg", "skill_od_thrsh_te_2", "skill_radmtry_total_penalty_2", "skill_mswflag_can_thrsh", "shp_param", "del_sigma", "cloud_filter_switch", "n_dec_mode", "ref_finalground_limit", "p_static"; } } gt3r { land_segments { String Dataset "segment_watermask", "delta_time_end", "latitude_20m", "rgt", "dem_flag", "msw_flag", "permafrost_prob", "cloud_flag_atm", "snr", "sigma_across", "layer_flag", "segment_snowcover", "beam_azimuth", "solar_azimuth", "psf_flag", "longitude", "latitude", "segment_id_end", "longitude_20m", "surf_type", "brightness_flag", "segment_landcover", "ph_removal_flag", "asr", "sigma_atlas_land", "segment_id_beg", "sigma_along", "dem_h", "beam_coelev", "sat_flag", "sigma_topo", "night_flag", "delta_time_beg", "sigma_h", "last_seg_extend", "column_od_asr", "atlas_pa", "ph_ndx_beg", "solar_elevation", "delta_time", "cloud_fold_flag", "n_seg_ph", "terrain_flg", "urban_flag", "permafrost_alt", "dem_removal_flag", "h_dif_ref"; canopy { String Dataset "h_canopy", "canopy_rh_conf", "h_median_canopy_abs", "h_min_canopy", "h_mean_canopy_abs", "h_median_canopy", "h_canopy_abs", "toc_roughness", "h_min_canopy_abs", "h_dif_canopy", "h_canopy_quad", "h_canopy_20m", "n_ca_photons", "photon_rate_can", "centroid_height", "canopy_h_metrics_abs", "can_noise", "h_mean_canopy", "subset_can_flag", "canopy_h_metrics", "n_toc_photons", "h_max_canopy_abs", "h_canopy_uncertainty", "photon_rate_can_nr", "can_quality_score", "canopy_openness", "h_max_canopy", "segment_cover"; } terrain { String Dataset "h_te_uncertainty", "h_te_mean", "h_te_min", "photon_rate_te", "h_te_interp", "h_te_max", "h_te_rh25", "h_te_skew", "h_te_best_fit_20m", "h_te_median", "h_te_best_fit", "h_te_std", "terrain_slope", "subset_te_flag", "n_te_photons", "h_te_mode", "te_quality_score"; } } signal_photons { String Dataset "classed_pc_flag", "classed_pc_indx", "ph_h", "d_flag", "delta_time", "ph_segment_id"; } } } H5_GLOBAL { String HDF5_OBJ_FULLPATH "H5_GLOBAL"; String short_name "ATL08"; String level "L3A"; String description "This data set (ATL08) contains along-track heights above the WGS84 ellipsoid (ITRF2014 reference frame) for the ground and canopy surfaces. The canopy and ground surfaces are processed in fixed 100 m data segments, which typically contain more than 100 sig"; String Conventions "CF-1.6"; String contributor_name "Thomas A Neumann (thomas.neumann@nasa.gov), Thorsten Markus (thorsten.markus@nasa.gov), Suneel Bhardwaj (suneel.bhardwaj@nasa.gov) David W Hancock III (david.w.hancock@nasa.gov)"; String contributor_role "Instrument Engineer, Investigator, Principle Investigator, Data Producer, Data Producer"; String date_type "UTC"; String featureType "trajectory"; String geospatial_lat_units "degrees_north"; String geospatial_lon_units "degrees_east"; String granule_type "ATL08"; String identifier_product_doi_authority "http://dx.doi.org"; 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 spatial_coverage_type "Horizontal"; String standard_name_vocabulary "CF-1.6"; String time_type "CCSDS UTC-A"; String date_created "2025-06-24T16:29:22.000000Z"; String hdfversion "HDF5 1.14.4"; String history "2025-06-24T16:29:22.000000Z;356bd535-f3e2-3aeb-b91b-bf93800a1093;Created by PGE atlas_l3a_ld Version 4.1"; String identifier_file_uuid "356bd535-f3e2-3aeb-b91b-bf93800a1093"; String identifier_product_format_version "4.1"; Float64 time_coverage_duration 510.; String time_coverage_end "2020-07-16T20:31:21.000000Z"; String time_coverage_start "2020-07-16T20:22:51.000000Z"; Float64 geospatial_lat_min 27.000105159300347; Float64 geospatial_lon_min 7.2780104575842639; Float64 geospatial_lat_max 59.504771275065515; Float64 geospatial_lon_max 11.868865242765473; 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 title "ATLAS/ICESat-2 L3A Land and Vegetation Height Quick Look"; String identifier_product_type "ATL08"; String identifier_product_doi "doi:10.5067/ATLAS/ATL08.007"; 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 ATL08 is to provide along-track land/canopy heights and associated statistics."; String keywords "EARTH SCIENCE > BIOSPHERE > VEGETATION > NONE > 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 "3A"; 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/rgt { String HDF5_OBJ_FULLPATH "/orbit_info/rgt"; String long_name "Reference Ground track"; String units "1"; String source "POD/PPD"; Int16 valid_min 1; Int16 valid_max 1387; String contentType "referenceInformation"; 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 coordinates "crossing_time"; } /orbit_info/bounding_polygon_lat1 { String HDF5_OBJ_FULLPATH "/orbit_info/bounding_polygon_lat1"; String long_name "Polygon1 Latitude"; String units "degrees_north"; String source "geo_poly"; Float64 valid_min -90.; Float64 valid_max 90.; String contentType "auxiliaryInformation"; String description "Latitude values for the first out of two possible bounding polygons"; } /orbit_info/cycle_number { String HDF5_OBJ_FULLPATH "/orbit_info/cycle_number"; String long_name "Cycle Number"; String units "1"; String source "Operations"; Int16 valid_min 0; Int16 valid_max 50; String contentType "referenceInformation"; String description "A count of the number of exact repeats of this reference orbit."; String coordinates "crossing_time"; } /orbit_info/crossing_time { String HDF5_OBJ_FULLPATH "/orbit_info/crossing_time"; String CLASS "DIMENSION_SCALE"; String NAME "crossing_time"; String long_name "Ascending Node Crossing Time"; String standard_name "time"; String units "seconds since 2018-01-01"; String source "POD/PPD"; 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."; } /orbit_info/lan { String HDF5_OBJ_FULLPATH "/orbit_info/lan"; String long_name "Ascending Node Longitude"; String units "degrees_east"; String source "POD/PPD"; Float64 valid_min -180.; Float64 valid_max 180.; String contentType "referenceInformation"; String description "Longitude at the ascending node crossing."; String coordinates "crossing_time"; } /orbit_info/sc_orient_time { String HDF5_OBJ_FULLPATH "/orbit_info/sc_orient_time"; String CLASS "DIMENSION_SCALE"; String NAME "sc_orient_time"; String long_name "Time of Last Spacecraft Orientation Change"; String standard_name "time"; String units "seconds since 2018-01-01"; String source "POD/PPD"; 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."; } /orbit_info/orbit_number { String HDF5_OBJ_FULLPATH "/orbit_info/orbit_number"; String long_name "Orbit Number"; String units "1"; String source "Operations"; UInt16 valid_min 1; UInt16 valid_max 65000; String contentType "referenceInformation"; String description "Unique identifying number for each planned ICESat-2 orbit."; String coordinates "crossing_time"; } /orbit_info/bounding_polygon_lon1 { String HDF5_OBJ_FULLPATH "/orbit_info/bounding_polygon_lon1"; String long_name "Polygon1 Longitude"; String units "degrees_east"; String source "geo_poly"; Float64 valid_min -180.; Float64 valid_max 180.; String contentType "auxiliaryInformation"; String description "Longitude values for the first out of two possible bounding polygons"; } /orbit_info/sc_orient { String HDF5_OBJ_FULLPATH "/orbit_info/sc_orient"; String long_name "Spacecraft Orientation"; String units "1"; String source "POD/PPD"; Int16 valid_min 0; Int16 valid_max 2; String contentType "referenceInformation"; 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 coordinates "sc_orient_time"; String flag_meanings "backward forward transition"; Int16 flag_values 0, 1, 2; } /METADATA/ { String HDF5_OBJ_FULLPATH "/METADATA/"; String description "ISO19115 Structured Metadata Represented within HDF5"; } /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/ProductSpecificationDocument/ { String HDF5_OBJ_FULLPATH "/METADATA/ProductSpecificationDocument/"; String ShortName "ATL08_SDP"; String characterSet "utf8"; String language "eng"; String publicationDate "Feb 2020"; String title "ICESat-2-SIPS-SPEC-4262 - ATLAS Science Algorithm Standard Data Product (SDP) Volume 7 (ATL08)."; String edition "v4.3"; } /METADATA/SeriesIdentification/ { String HDF5_OBJ_FULLPATH "/METADATA/SeriesIdentification/"; String maintenanceAndUpdateFrequency "asNeeded"; String maintenanceDate "SET_BY_META"; String VersionID "007"; 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 L3A Land and Vegetation Height Quick Look"; String shortName "ATL08"; String identifier_product_DOI "doi:10.5067/ATLAS/ATL08.007"; String revisionDate "2022-08-09"; String resourceProviderOrganizationName "National Aeronautics and Space Administration (NASA)"; String abstract "The ICESat-2 ATL08 standard data product contains along-track heights of ground and canopy surface at varying length scales. Where data permits, this includes estimates of canopy height, relative canopy cover, canopy height distributions, surface roughness, surface slope/aspect, and apparent reflectance."; String purpose "The purpose of ATL08 is to provide along-track land/canopy heights and associated statistics."; String credit "The software that generates the ATL08 product was designed and implemented within the ICESat-2 Science Investigator-led Processing System at the NASA Goddard Space Flight Center in Greenbelt, Maryland."; 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 "2025-06-24T16:29:22.000000Z"; String uuid "356bd535-f3e2-3aeb-b91b-bf93800a1093"; String fileName "ATL08_20200716202251_03280806_007_01.h5"; String VersionID "007"; String language "eng"; String characterSet "utf8"; String shortName "ATL08"; String originatorOrganizationName "GSFC I-SIPS > ICESat-2 Science Investigator-led Processing System"; String abstract "The ICESat-2 ATL08 standard data product contains along-track heights of ground and canopy surface at varying length scales. Where data permits, this includes estimates of canopy height, relative canopy cover, canopy height distributions, surface roughness, surface slope/aspect, and apparent reflectance."; String purpose "The purpose of ATL08 is to provide along-track land/canopy heights and associated statistics."; String credit "The software that generates the ATL08 product was designed and implemented within the ICESat-2 Science Investigator-led Processing System at the NASA Goddard Space Flight Center in Greenbelt, Maryland."; String status "onGoing"; String topicCategory "geoscientificInformation"; } /METADATA/Extent/ { String HDF5_OBJ_FULLPATH "/METADATA/Extent/"; Float64 northBoundLatitude 59.504771275065515; Float64 eastBoundLongitude 11.868865242765473; Float64 southBoundLatitude 27.000105159300347; Float64 westBoundLongitude 7.2780104575842639; String rangeBeginningDateTime "2020-07-16T20:22:51.006883Z"; String rangeEndingDateTime "2020-07-16T20:31:21.602596Z"; } /METADATA/iso_19139_dataset_xml { String HDF5_OBJ_FULLPATH "/METADATA/iso_19139_dataset_xml"; String long_name "ISO 19139 Dataset XML"; String description "ISO 19139 Dataset XML"; } /METADATA/iso_19139_series_xml { String HDF5_OBJ_FULLPATH "/METADATA/iso_19139_series_xml"; String long_name "ISO 19139 Series XML"; String description "ISO 19139 Series XML"; } /METADATA/QADatasetIdentification/ { String HDF5_OBJ_FULLPATH "/METADATA/QADatasetIdentification/"; String creationDate "2025-06-24T17:10:31.000000Z"; 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 fileName "ATL08_20200716202251_03280806_007_01.qa"; } /METADATA/Lineage/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/"; } /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_ld_019563783.ctl"; String shortName "CNTL"; String version "1"; } /METADATA/Lineage/ANC28/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC28/"; String description "DTU Mean Sea Surface re-referenced to the WGS84 ellipsoid."; String uuid "SET_BY_PGE"; String version "SET_BY_PGE"; String fileName "SET_BY_PGE"; String shortName "SET_BY_PGE"; } /METADATA/Lineage/ANC14/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC14/"; String description "Woody Vegetation Coverage Fraction"; String fileName "ANC14-00_20210831170932_20210601_01.h5"; String shortName "ANC14"; String uuid "bb667bc0-93a8-34be-9280-04a2f8436aff"; String version "20210601"; } /METADATA/Lineage/ANC06-02/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC06-02/"; String description "ArcticDEM 32m Digital Elevation Model reformatted into HDF5."; String fileName "arcticdem32m_20190611_001_01.h5"; String shortName "ANC06-02"; String uuid "ce07ef72-0bf4-353b-8475-fb568b029905"; String version "20190611"; } /METADATA/Lineage/ANC06-03/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC06-03/"; String description "REMA Antarctica 100m Digital Elevation Model filled and reformatted into HDF5"; String fileName "atl06rema100m_20190628_001_01.h5"; String shortName "ANC06-03"; String uuid "3e0a81bd-bbd5-35fa-b868-3254f9355b7f"; String version "20190628"; } /METADATA/Lineage/ANC25-08/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC25-08/"; String description "HDF5 template file that defines the organization and default content of the product."; String fileName "ANC25-08_20250523205531_041_01.h5"; String shortName "ANC25-08"; String uuid "9f230450-5edc-399f-8f3c-4522f1910ab3"; String version "041"; } /METADATA/Lineage/ANC46/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC46/"; String description "Urban Flag File"; String fileName "dlr_guf_20210115_001_01.h5"; String shortName "ANC46"; String uuid "d555b51c-dcd5-34b1-99c4-e056594cf5b5"; String version "20210115"; } /METADATA/Lineage/ANC47/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC47/"; String description "Permafrost File"; String fileName "ESApermafrost2019_20230918_001_01.nc"; String shortName "ANC47"; String uuid "39365b1d-d7cd-38b1-92b2-3d13bdd70ba0"; String version "20230918"; } /METADATA/Lineage/ANC33/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC33/"; String description "Water Mask File"; String fileName "watermask_2000_20180301_001_global.h5"; String shortName "ANC33"; String uuid "1e7d3697-c576-308d-9197-21d827ac21db"; String version "20180301"; } /METADATA/Lineage/ANC18/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC18/"; String description "Global Land Cover Classification File"; String fileName "cop_classification_20210603_001_01.h5"; String shortName "ANC18"; String uuid "ffb62f02-84be-369e-9840-35328cd2bee8"; String version "20210603"; } /METADATA/Lineage/ANC38-08/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC38-08/"; String description "ISO 19139 XML file containing DataSet-level metadata information."; String fileName "ATL08.esdt.dataset.xml"; String shortName "ANC38-08"; String uuid "390c9903-9c0d-3b90-9e38-4998fd8b6e13"; String version "007"; } /METADATA/Lineage/ATL03/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ATL03/"; String description "ICESat-2 ATLAS L2A Global Geolocated Photon data products."; String fileName "ATL03_20200716202251_03280806_007_01.h5"; String shortName "ATL03"; String uuid "0f256bf6-61e1-31c1-a138-25a971f25418"; String version "007"; Int32 start_cycle 8; Int32 end_cycle 8; Int32 start_orbit 10238; Int32 end_orbit 10238; Int32 start_rgt 328; Int32 end_rgt 328; Int32 start_region 6; Int32 end_region 6; Int32 start_geoseg 671053; Int32 end_geoseg 852078; } /METADATA/Lineage/ATL09/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ATL09/"; String description "ICESat-2 ATLAS L3A atmosphere data products."; String fileName "ATL09_20200716195119_03280801_007_01.h5"; String shortName "ATL09"; String uuid "19705172-ba3e-3436-80f6-574027939bc7"; String version "007"; Int32 start_cycle 8; Int32 end_cycle 8; Int32 start_orbit 10238; Int32 end_orbit 10238; Int32 start_rgt 328; Int32 end_rgt 328; Int32 start_region 1; Int32 end_region 14; Int32 start_geoseg 64; Int32 end_geoseg 2007133; } /METADATA/Lineage/ANC06-01/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC06-01/"; String description "MERIT 3 arcsec Digital Elevation Model reformatted into HDF5 and re-referenced to the WGS-84 ellipsoid."; String fileName "merit_3as_20200617_001_01.h5"; String shortName "ANC06-01"; String uuid "3db8ab65-d2ac-37c7-86db-17c762268673"; String version "20200617"; } /METADATA/Lineage/ANC26-08/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC26-08/"; String description "HDF5 template file that defines the organization and default content of the product metadata."; String fileName "ANC26-08_20250523205538_041_01.h5"; String shortName "ANC26-08"; String uuid "1d565967-3167-3bee-bee3-ed373776e5b8"; String version "041"; } /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/Lineage/ANC36-08/ { String HDF5_OBJ_FULLPATH "/METADATA/Lineage/ANC36-08/"; String description "ISO 19139 XML file containing Series-level metadata information."; String fileName "ATL08.esdt.series.xml"; String shortName "ANC36-08"; String uuid "8fa6664b-4daf-3f2f-834e-c8911c46ea18"; String version "007"; } /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 3.1.3"; String softwareDate "Apr 8 2025"; String softwareTitle "Creates ATLAS HDF5 browse files"; String runTimeParameters "CTL_atlas_l3a_ld_019563783.ctl"; String stepDateTime "2025-06-24T17:10:41.000000Z"; } /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 5.1.3"; String softwareDate "Apr 8 2025"; String softwareTitle "Creates ATLAS XML metadata files"; String runTimeParameters "CTL_atlas_l3a_ld_019563783.ctl"; String stepDateTime "2025-06-24T17:10:58.000000Z"; } /METADATA/ProcessStep/PGE/ { String HDF5_OBJ_FULLPATH "/METADATA/ProcessStep/PGE/"; String ATBDDate "01/17/2020"; String ATBDTitle "Algorithm Theoretical Basis Document (ATBD) for Land - Vegetation Along-Track Products (ATL08)"; String ATBDVersion "v.3"; String documentDate "Feb 2020"; String documentation "ATLAS Science Algorithm Software Design Description (SDD) - Volume 12 (atlas_l3a_ld)"; String processDescription "Determines heights of ground and canopy surface. Where data permits, includes estimates of canopy height, relative canopy cover, canopy height distributions, surface roughness, surface slope/aspect and apparent reflectance."; String identifier "atlas_l3a_ld"; String softwareVersion "Version 4.1"; String softwareDate "Apr 8 2025"; String softwareTitle "ASAS L3A Land PGE"; String runTimeParameters "CTL_atlas_l3a_ld_019563783.ctl"; String stepDateTime "2025-06-24T16:29:22.000000Z"; } /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 "atl08_qa_util"; String softwareVersion "Version 4.1"; String softwareDate "Apr 8 2025"; String softwareTitle "ATL08 QA Utility"; String runTimeParameters "CTL_atlas_l3a_ld_019563783.ctl"; String stepDateTime "2025-06-24T17:10:31.000000Z"; } /ds_metrics { String HDF5_OBJ_FULLPATH "/ds_metrics"; String CLASS "DIMENSION_SCALE"; String NAME "ds_metrics"; String long_name "Metrics"; String units "1"; String source "Dim Scale"; Int16 valid_min 1; Int16 valid_max 18; String contentType "referenceInformation"; String description "Dimension scale for metrics."; String flag_meanings "metrics1 metrics2 metrics3 metrics4 metrics5 metrics6 metrics7 metrics8 metrics9 metrics10 metrics11 metrics12 metrics13 metrics14 metrics15 metrics16 metrics17 metrics18"; Int16 flag_values 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18; } /gt1r/ { String HDF5_OBJ_FULLPATH "/gt1r/"; String atlas_pce "pce1"; String atlas_beam_type "weak"; String atlas_spot_number "2"; String sc_orientation "Backward"; String groundtrack_id "gt1r"; String atmosphere_profile "profile_1"; } /gt1r/land_segments/ { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/"; String description "Contains data categorized as land at 100 meter intervals."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt1r/land_segments/segment_watermask { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/segment_watermask"; String long_name "segment watermask"; String units "1"; String source "ATL08 ATBD segment_watermask"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Water mask(i.e. flag) indicating inland water as referenced from the Global Raster Water Mask(ANC33) at 250 m spatial resolution."; String coordinates "delta_time latitude longitude"; String flag_meanings "no_water water Undetermined"; Byte flag_values 0, 1, 255; } /gt1r/land_segments/delta_time_end { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/delta_time_end"; String long_name "delta time end"; String units "seconds since 2018-01-01"; String source "Derived (gps_seconds-gps_sec_offset)"; String contentType "referenceInformation"; String description "Time of the last photon contained within the data segment, in seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/latitude_20m { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/latitude_20m"; Float32 _FillValue 3.402823466e+38; String long_name "latitude of 20m segments"; String units "degree"; String source "ATBD Geosegment latitude"; Float32 valid_min -90.; Float32 valid_max 90.; String contentType "modelResult"; String description "Center latitude of 20m geosegments within each 100m land segment."; String coordinates "latitude longitude delta_time"; } /gt1r/land_segments/rgt { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/rgt"; String long_name "reference ground track"; String units "1"; String source "Operations"; Int16 valid_min 1; Int16 valid_max 1387; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt1r/land_segments/dem_flag { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/dem_flag"; String long_name "dem source flag"; String units "1"; String source "Atmosphere ATBD"; Int16 valid_min 0; Int16 valid_max 127; String contentType "referenceInformation"; String description "Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=Global, 3=MSS, 4=Antarctic."; String coordinates "delta_time latitude longitude"; String flag_meanings "none arctic global mss antarctic Undetermined"; Int16 flag_values 0, 1, 2, 3, 4, 127; } /gt1r/land_segments/msw_flag { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/msw_flag"; String long_name "multiple scattering warning flag"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 127; String contentType "qualityInformation"; String description "Multiple Scattering Warning flag. If no layers were detected, then msw_flag = 0. If blowing snow is detected and its estimated optical depth is greater than or equal to 0.5, then msw_flag = 5. If the blowing snow optical depth is less than 0.5, then msw_flag = 4. If no blowing snow is detected but there are cloud or aerosol layers detected, the msw_flag assumes values of 1 to 3 based on the height of the bottom of the lowest layer: < 1 km, msw_flag = 3; 1-3 km, msw_flag = 2; > 3km, msw_flag = 1. A value of 127 indicates that the signal to noise of the data was too low to reliably ascertain the presence of cloud or blowing snow. We expect values of 127 to occur only during daylight."; String coordinates "delta_time latitude longitude"; 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 127, 0, 1, 2, 3, 4, 5; } /gt1r/land_segments/permafrost_prob { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/permafrost_prob"; Int16 _FillValue 127; String long_name "permafrost probaility"; String standard_name "permafrost_prob"; String units "percent"; String source "ESA CCI, ANC47"; Int16 valid_min 0; Int16 valid_max 100; String contentType "referenceInformation"; String description "Permafrost probability (0 - 100) derived via percent of permafrost within pixel cell area in ESA CCI 2019 northern hemisphere permafrost dataset"; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/cloud_flag_atm { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/cloud_flag_atm"; Int16 _FillValue 127; String long_name "cloud flag atm"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 10; String contentType "qualityInformation"; String description "Cloud confidence flag from ATL09 that indicates the number of cloud or aerosol layers identified in each 25Hz atmospheric profile. If the flag is greater than 0, aerosols or clouds could be present. Valid range is 0 - 10."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/snr { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/snr"; Float32 _FillValue 3.402823466e+38; String long_name "signal to noise ratio"; String units "1"; String source "ATBD Noise filtering via DRAGANN"; String contentType "modelResult"; String description "The signal to noise ratio of geolocated photons as determined by the ratio of the superset of ATL03 signal and DRAGANN found signal photons used for processing the ATL08 segments to the background photons (i.e. noise) within the same ATL08 segments."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/canopy/ { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/"; String description "Contains height parameters based on the land algorithm."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt1r/land_segments/canopy/h_canopy { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/h_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "height canopy"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "98% height of all the individual canopy relative heights for the segment above the estimated terrain surface. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/canopy_rh_conf { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/canopy_rh_conf"; String units "1"; String long_name "canopy relative height confidence"; String source "Land/Veg ATBD Vegetation Parameters"; Int16 valid_min 0; Int16 valid_max 2; String contentType "modelResult"; String description "Canopy relative height confidence flag based on percentage of ground and canopy photons within a segment: 0 (<5% canopy), 1 (>5% canopy, <5% ground), 2 (>5% canopy, >5% ground)."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "<5%_canopy >=5%_canopy_<5%_ground >=5%_canopy_>=5%_ground"; Int16 flag_values 0, 1, 2; } /gt1r/land_segments/canopy/h_median_canopy_abs { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/h_median_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute segment median canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The median of individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/h_min_canopy { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/h_min_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "minimum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The minimum of relative individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/h_mean_canopy_abs { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/h_mean_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute mean canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Mean of the individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/h_median_canopy { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/h_median_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "median canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The median of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. This parameter should be equivalent to RH50 reported in the literature."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/h_canopy_abs { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/h_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute segment canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The 98% height of all the absolute individual canopy heights referenced above the WGS84 ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/toc_roughness { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/toc_roughness"; Float32 _FillValue 3.402823466e+38; String long_name "top of canopy roughness"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Standard deviation of the relative heights of all photons classified as top of canopy within the segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/h_min_canopy_abs { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/h_min_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute minimum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The minimum of absolute individual canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/h_dif_canopy { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/h_dif_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "canopy diff to median height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Difference between h_canopy and h_median_canopy"; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/h_canopy_quad { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/h_canopy_quad"; Float32 _FillValue 3.402823466e+38; String long_name "canopy quadratic mean"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The quadratic mean height of individual classified relative canopy photon heights above the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/h_canopy_20m { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/h_canopy_20m"; String units "m"; Float32 _FillValue 3.402823466e+38; String long_name "canopy height 20m"; String source "ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Canopy height for each 20m geosegment with each 100m land segment."; String coordinates "../latitude ../longitude ../delta_time"; } /gt1r/land_segments/canopy/n_ca_photons { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/n_ca_photons"; String long_name "number canopy photons"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The number of photons classified as canopy within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/photon_rate_can { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/photon_rate_can"; Float32 _FillValue 3.402823466e+38; String long_name "Canopy photon rate"; String units "s^-1"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Calculated photon rate of canopy photons within each 100m segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/centroid_height { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/centroid_height"; Float32 _FillValue 3.402823466e+38; String long_name "centroid height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Optical centroid of all photons classified as either canopy or ground points within the segment. The heights used in this calculation are absolute heights above the reference ellipsoid. This parameter is equivalent to the centroid height produced ICESat GLA14."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/canopy_h_metrics_abs { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/canopy_h_metrics_abs"; Float32 _FillValue 3.402823466e+38; String long_name "canopy absolute height metrics"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Height metrics based on the cumulative distribution of absolute canopy heights above the WGS84 Ellipsoid. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/can_noise { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/can_noise"; Float32 _FillValue 3.402823466e+38; String long_name "canopy noise rate"; String units "count/meter"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Number of noise photons calculated that fall within the canopy height for each 100 m segment based on ATL03 background rate parameters."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/h_mean_canopy { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/h_mean_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "mean canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Mean of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/subset_can_flag { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/subset_can_flag"; Int16 _FillValue 127; String long_name "subset canopy flag"; String units "1"; String source "Land ATBD Vegetation Parameters"; Int16 valid_min -1; Int16 valid_max 1; String contentType "modelResult"; String description "Quality flag indicating the canopy photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "no_photon_data_within_geosegment no_canopy_photons_within_geosegment canopy_photons_present_within_geosegment"; Int16 flag_values -1, 0, 1; } /gt1r/land_segments/canopy/canopy_h_metrics { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/canopy_h_metrics"; Float32 _FillValue 3.402823466e+38; String long_name "canopy height metrics"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Height metrics based on the cumulative distribution of relative canopy heights above the interpolated ground surface. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/n_toc_photons { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/n_toc_photons"; String long_name "number top of canopy photons"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The number of photons classified as top of canopy within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/h_max_canopy_abs { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/h_max_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute maximum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Maximum of individual absolute canopy heights within segment referenced above the WGS84 ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/h_canopy_uncertainty { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/h_canopy_uncertainty"; Float32 _FillValue 3.402823466e+38; String long_name "segment canopy height uncertainty"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "qualityInformation"; String description "Uncertainty of the relative canopy heights for the segment. Incorporates all systematic uncertainties as well as uncertainty from errors of identified photons. See section 1 and equations 1.4 and 1.5 of the ATL08 ATBD."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/photon_rate_can_nr { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/photon_rate_can_nr"; Float32 _FillValue 3.402823466e+38; String long_name "noise reduced number of canopy photons"; String units "s^-1"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Noise removed photon canopy rate within each 100 m segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/can_quality_score { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/can_quality_score"; String units "1"; String source "Land ATBD Vegetation Parameters"; Int16 valid_min 0; Int16 valid_max 100; String contentType "modelResult"; String description "Canopy quality score based on coincident conditions, from ATL08 ATBD section titled \"Canopy Quality Score\"."; String coordinates "../delta_time ../latitude ../longitude"; Int16 _FillValue 127; String long_name "canopy quality score"; } /gt1r/land_segments/canopy/canopy_openness { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/canopy_openness"; Float32 _FillValue 3.402823466e+38; String long_name "canopy openness"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Standard Deviation of all photons classified as canopy photons within the segment to provide inference of canopy openness."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/h_max_canopy { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/h_max_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "maximum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Relative maximum of individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. Should be equivalent to RH100 metric reported in the literature."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/canopy/segment_cover { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/canopy/segment_cover"; Int16 _FillValue 32767; String long_name "canopy cover percentage"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Average percentage value of the valid (value <= 100) Copernicus fractional cover product for each 100 m segment. This data is temporally static, and is the summation of forest and shrub land cover fractions. Source data from: https://land.copernicus.eu/en/products/global-dynamic-land-cover/copernicus-global-land-service-land-cover-100m-collection-3-epoch-2019-globe ."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/sigma_across { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/sigma_across"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas y"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Total cross-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_across. Sigma_atlas_y is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/terrain/ { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/"; String description "Contains terrain parameters at a 100m aggregation."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt1r/land_segments/terrain/h_te_uncertainty { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/h_te_uncertainty"; Float32 _FillValue 3.402823466e+38; String long_name "uncertainty of h_te_mean"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Uncertainty of the mean terrain height for the segment. This uncertainty incorporates all systematic uncertainties(e.g. timing orbits, geolocation,etc.) as well as uncertainty from errors of identified photons. This parameter is described in section 1, equation 1.4 in ATL08 ATBD."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/terrain/h_te_mean { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/h_te_mean"; Float32 _FillValue 3.402823466e+38; String long_name "mean terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The mean of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/terrain/h_te_min { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/h_te_min"; Float32 _FillValue 3.402823466e+38; String long_name "minimum terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The minimum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/terrain/photon_rate_te { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/photon_rate_te"; Float32 _FillValue 3.402823466e+38; String long_name "Terrain photon rate"; String units "s^-1"; String source "Land ATBD Land Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Calculated photon rate of terrain photons within each 100m segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/terrain/h_te_interp { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/h_te_interp"; Float32 _FillValue 3.402823466e+38; String long_name "interpolated terrain surface height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Interpolated terrain surface height above the WGS84 Ellipsoid at the midpoint of the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/terrain/h_te_max { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/h_te_max"; Float32 _FillValue 3.402823466e+38; String long_name "maximum terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The maximum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/terrain/h_te_rh25 { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/h_te_rh25"; String units "meters"; Float32 _FillValue 3.402823466e+38; String long_name "Terrain height 25% percentile"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The terrain elevation from the 25% height. The classified ground photons are sorted into a cumulative distribution and the height associated with the 25% height for that segment is reported."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/terrain/h_te_skew { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/h_te_skew"; Float32 _FillValue 3.402823466e+38; String long_name "skew of terrain heights"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The skewness of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/terrain/h_te_best_fit_20m { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/h_te_best_fit_20m"; Float32 _FillValue 3.402823466e+38; String long_name "best fit 20m"; String units "m"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Best fit terrain height to center of each 20m geosegment within each 100m land segment."; String coordinates "../latitude ../longitude ../delta_time"; } /gt1r/land_segments/terrain/h_te_median { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/h_te_median"; Float32 _FillValue 3.402823466e+38; String long_name "median terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The median of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/terrain/h_te_best_fit { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/h_te_best_fit"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain height best fit"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The best fit terrain elevation at the the mid-point location of each 100m segment. The mid-segment terrain elevation is determined by selecting the best of three fits- linear, 3rd order and 4th order polynomials - to the terrain photons and interpolating the elevation at the mid-point location of the 100 m segment. For the linear fit, a slope correction and weighting is applied to each ground photon based on the distance to the slope height at the center of the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/terrain/h_te_std { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/h_te_std"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain roughness"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The standard deviation of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/terrain/terrain_slope { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/terrain_slope"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain slope"; String units "1"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The along-track slope of terrain, within each segment;computed by a linear fit of terrain classified photons. Slope is in units of delta height over delta along track distance."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/terrain/subset_te_flag { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/subset_te_flag"; Int16 _FillValue 127; String long_name "subset terrain flag"; String units "1"; String source "Land ATBD Land Parameters"; Int16 valid_min -1; Int16 valid_max 1; String contentType "modelResult"; String description "Quality flag indicating the terrain photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "no_photon_data_within_geosegment no_terrain_photons_within_geosegment terrain_photons_present_within_geosegment"; Int16 flag_values -1, 0, 1; } /gt1r/land_segments/terrain/n_te_photons { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/n_te_photons"; String long_name "number of ground photons"; String units "1"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The number of the photons classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/terrain/h_te_mode { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/h_te_mode"; Float32 _FillValue 3.402823466e+38; String long_name "mode of terrain heights"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The mode of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/terrain/te_quality_score { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain/te_quality_score"; Int16 _FillValue 127; String long_name "terrain quality score"; String units "1"; String source "Land ATBD Land Parameters"; Int16 valid_min 0; Int16 valid_max 100; String contentType "modelResult"; String description "Quality score based on coincident conditions, from ATL08 ATBD section titled \"Terrain Quality Score\"."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1r/land_segments/layer_flag { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/layer_flag"; String long_name "consolidated cloud flag"; String units "1"; String source "ATL09"; String contentType "modelResult"; 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 coordinates "delta_time latitude longitude"; String flag_meanings "likely_clear likely_cloudy"; Int16 flag_values 0, 1; } /gt1r/land_segments/segment_snowcover { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/segment_snowcover"; String long_name "segment snowcover"; String units "1"; String source "ATL08 ATBD segment_snowcover"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Daily snow/ice cover from ATL09 at the 25 Hz rate(275m) indicating likely presence of snow and ice within each segment. 0=ice free water; 1=snow free land; 2=snow; 3=ice."; String coordinates "delta_time latitude longitude"; String flag_meanings "ice_free_water snow_free_land snow ice Undetermined"; Byte flag_values 0, 1, 2, 3, 255; } /gt1r/land_segments/beam_azimuth { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/beam_azimuth"; Float32 _FillValue 3.402823466e+38; String long_name "beam azimuth"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; String description "Azimuth(in radians) of the unit pointing vector for the reference photon in the local ENU frame in radians. The angle is measured from north and positive towards East."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/solar_azimuth { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/solar_azimuth"; String long_name "solar azimuth"; String units "degrees_east"; String source "ATL03 ATBD"; String contentType "referenceInformation"; String description "The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/psf_flag { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/psf_flag"; String long_name "point spread function flag"; String units "1"; String source "Land/Veg ATBD Refine Ground Estimates"; Byte valid_min 0; Byte valid_max 255; String contentType "referenceInformation"; String description "Flag is set to 1 if the point spread function (computed as sigma_atlas_land) has exceeded the threshold (1 m)"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt1r/land_segments/longitude { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/longitude"; String long_name "longitude"; String standard_name "longitude"; String units "degrees"; String source "Land ATBD segment parameters for Land Products"; Float32 valid_min -180.; Float32 valid_max 180.; String contentType "modelResult"; String description "Longitude of the center-most signal photon within each segment."; String coordinates "delta_time latitude"; } /gt1r/land_segments/latitude { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/latitude"; String long_name "latitude"; String standard_name "latitude"; String units "degrees"; String source "Land ATBD segment parameters for Land Products"; Float32 valid_min -90.; Float32 valid_max 90.; String contentType "modelResult"; String description "Latitude of the center-most signal photon within each segment."; String coordinates "delta_time longitude"; } /gt1r/land_segments/segment_id_end { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/segment_id_end"; String long_name "end geolocation segment bin"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Geolocation segment number of the last photon in the land segment."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/longitude_20m { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/longitude_20m"; Float32 _FillValue 3.402823466e+38; String long_name "longitude of 20m segments"; String units "degree"; String source "ATBD Geosegment longitude"; Float32 valid_min -180.; Float32 valid_max 180.; String contentType "modelResult"; String description "Center longitude of 20m geosegments within each 100m land segment."; String coordinates "latitude longitude delta_time"; } /gt1r/land_segments/surf_type { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/surf_type"; String long_name "surface type"; String units "1"; String source "ATL03 ATBD"; Int16 valid_min 0; Int16 valid_max 1; String contentType "referenceInformation"; String description "Flags describing which surface types this interval is associated with. 0=not type, 1=is type. Order of array is land, ocean, sea ice, land ice, inland water."; String coordinates "delta_time latitude longitude"; String flag_meanings "not_type is_type"; Int16 flag_values 0, 1; } /gt1r/land_segments/brightness_flag { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/brightness_flag"; String long_name "brightness flag"; String units "1"; String source "Land ATBD Brightness_flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "Flag indicating that the ground surface is bright (e.g. snow-covered or other bright surfaces)"; String coordinates "delta_time latitude longitude"; String flag_meanings "not_bright_surface bright_surface Undetermined"; Byte flag_values 0, 1, 255; } /gt1r/land_segments/segment_landcover { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/segment_landcover"; String long_name "segment landcover"; String units "1"; String source "ATL08 ATBD segment_landcover"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "UN-FAO Land Cover Surface type classification as reference from Copernicus Land Cover(ANC18) at the 100m resolution."; String coordinates "delta_time latitude longitude"; String flag_meanings "No_data Closed_forest_evergreen_needle_leaf Closed_forest_deciduous_needle_leaf Closed_forest_evergreen_broad_leaf Closed_forest_deciduous_broad_leaf Closed_forest_mixed Closed_forest_unknown Open_forest_evergreen_needle_leaf Open_forest_deciduous_needle_leaf Open_forest_evergreen_broad_leaf Open_forest_deciduous_broad_leaf Open_forest_mixed Open_forest_unknown Shrubs Herbaceous Herbaceous_wetleand Moss_and_lichen Bare_sparse_vegetation Cultivated_and_managed_vegetation_agriculture Urban_built_up Snow_and_ice Permanent_water_bodies Open_sea Undetermined"; Byte flag_values 0, 111, 113, 112, 114, 115, 116, 121, 123, 122, 124, 125, 126, 20, 30, 90, 100, 60, 40, 50, 70, 80, 200, 255; } /gt1r/land_segments/ph_removal_flag { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/ph_removal_flag"; String long_name "ph removal flag"; String units "1"; String source "ATBD Final photon classification QA"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Flag indicating more than ph_removal_percent_limit (default 50.0) removed from land segment due to failing QA tests"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt1r/land_segments/asr { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/asr"; Float32 _FillValue 3.402823466e+38; String long_name "apparent surface reflectance"; String units "1"; String source "ATL09"; String contentType "auxiliaryInformation"; String description "Apparent surface reflectance"; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/sigma_atlas_land { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/sigma_atlas_land"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas land"; String units "1"; String source "Land ATBD Refine Ground Estimates"; String contentType "referenceInformation"; String description "Total vertical geolocation error due to ranging and local surface slope. The parameter is computed for ATL08 as described in equation 1.2 ATL08 ATBD."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/segment_id_beg { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/segment_id_beg"; String long_name "begin geolocation segment bin"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Geolocation segment number of the first photon in the land segment."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/sigma_along { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/sigma_along"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas x"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Total along-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_along. Sigma_atlas_x is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/dem_h { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/dem_h"; Float32 _FillValue 3.402823466e+38; String long_name "dem height"; String units "meters"; String source "Arctic, Antarctic, Global, MSS DEM"; String contentType "referenceInformation"; String description "Best available DEM (in priority of Arctic/Antarctic/Global/MSS) value at the geolocation point. Height is in meters above the WGS84 Ellipsoid."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/beam_coelev { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/beam_coelev"; Float32 _FillValue 3.402823466e+38; String long_name "beam co-elevation"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt1r/land_segments/sat_flag { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/sat_flag"; String long_name "saturation flag"; String units "1"; String source "ATL03, Land ATBD Saturation Flag"; Int16 valid_min -1; Int16 valid_max 127; String contentType "auxiliaryInformation"; String description "Flag derived from full_sat_fract on the ATL03 data product, averaged over 5 geosegments in 100m land segment"; String coordinates "delta_time latitude longitude"; String flag_meanings "no_saturation_detected saturation_detected not_enough_valid_data Undetermined"; Int16 flag_values 0, 1, -1, 127; } /gt1r/land_segments/sigma_topo { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/sigma_topo"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas topo"; String units "1"; String source "Land ATBD Refine Ground Estimates"; String contentType "referenceInformation"; String description "Total uncertainty that include sigma_h plus geolocation uncertainty due to local slope (equation 1.3). The local slope is multiplied by the geolocation uncertainty factor. This will be used to determine the total vertical geolocation error due to ranging and local slope."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/night_flag { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/night_flag"; String long_name "night flag"; String units "1"; String source "Land ATBD Night_Flag"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Flag indicating the data were acquired in night conditions: 0=day, 1=night. Flag is derived from solar elevation at the geolocated segment. IF solar elevation is above threshold it is day, if not then it is night. Threshold is set in atlas_l3a_const_mod."; String coordinates "delta_time latitude longitude"; String flag_meanings "day night Undetermined"; Byte flag_values 0, 1, 255; } /gt1r/land_segments/delta_time_beg { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/delta_time_beg"; String long_name "delta time begin"; String units "seconds since 2018-01-01"; String source "Derived (gps_seconds-gps_sec_offset)"; String contentType "referenceInformation"; String description "Time of the first photon contained within the data segment, in seconds since the ATLAS SDP GPS Epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/sigma_h { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/sigma_h"; Float32 _FillValue 3.402823466e+38; String long_name "height uncertainty"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m) provided at the geolocation segment rate on ATL03. Sigma_h is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/last_seg_extend { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/last_seg_extend"; String long_name "last segment extended"; String standard_name "last_seg_extend"; String units "kilometers"; String source "Land ATBD Preparing ATL03 data for input"; String contentType "auxiliaryInformation"; String description "The distance (km) that the last ATL08 processing segment in a file is either extended or overlapped with the previous ATL08 processing segment."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/column_od_asr { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/column_od_asr"; Float32 _FillValue 3.402823466e+38; String long_name "Column optical depth from ASR"; String units "1"; String source "ATL09"; String contentType "auxiliaryInformation"; String description "Optical depth of atmosphere column based on apparent surface reflectance and the assumed actual surface reflectance."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/atlas_pa { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/atlas_pa"; Float32 _FillValue 3.402823466e+38; String long_name "atlas pointing angle"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; String description "Off nadir pointing angle (in radians) of the satellite to increase spatial sampling in the non-polar regions. ATLAS_PA =radians(90degs-beam_coelev)."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/ph_ndx_beg { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/ph_ndx_beg"; String long_name "photon index begin"; String units "1"; String source "Derived"; String contentType "auxiliaryInformation"; String description "Index (1-based) within the photon-rate data (/land_segments/photons) of the first photon within this each land segment."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/solar_elevation { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/solar_elevation"; String long_name "solar elevation"; String units "degrees"; String source "ATL03 ATBD"; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt1r/land_segments/delta_time { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/delta_time"; String CLASS "DIMENSION_SCALE"; String long_name "mean_pass_time"; String standard_name "time"; String units "seconds since 2018-01-01"; String source "Land ATBD segment parameters for Land Products"; String contentType "referenceInformation"; String description "Mean time for the segment in number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "latitude longitude"; String NAME "delta_time"; } /gt1r/land_segments/cloud_fold_flag { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/cloud_fold_flag"; String long_name "cloud folding flag"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 127; String contentType "modelResult"; String description "Flag that indicates this profile likely contains cloud signal folded down from above 15 km to the last 2-3 km of the profile. See ATL09 ATBD Table 3.9 for detailed flag value meanings."; String coordinates "delta_time latitude longitude"; String flag_meanings "no_folding goes5_indicates profile_indicates both_indicate outside_limits"; Int16 flag_values 0, 1, 2, 3, 127; } /gt1r/land_segments/n_seg_ph { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/n_seg_ph"; String long_name "number of photons"; String units "1"; String source "Derived"; String contentType "auxiliaryInformation"; String description "Number of photons within each land segment."; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/terrain_flg { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/terrain_flg"; String long_name "terrain flag"; String units "1"; String source "Land ATBD Segment_terrain flag"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Terrain flag quality check to indicate a deviation above a threshold from the reference DEM height reported on the product."; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt1r/land_segments/urban_flag { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/urban_flag"; String long_name "segment urban flag"; String units "1"; String source "Land ATBD Urban_flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "The urban flag indicates that a segment is likely located over an urban area as determined by coincident pixels in the Global Urban Footprint (GUF) 0.4 arcsecond product."; String coordinates "delta_time latitude longitude"; String flag_meanings "not_urban urban Undetermined"; Byte flag_values 0, 1, 255; } /gt1r/land_segments/permafrost_alt { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/permafrost_alt"; Float32 _FillValue 3.402823466e+38; String long_name "permafrost active layer thickness"; String standard_name "permafrost_alt"; String units "meters"; String source "ESA CCI, ANC47"; Float32 valid_min 0.; Float32 valid_max 100.; String contentType "referenceInformation"; String description "Permafrost active layer thickness (m) from ESA CCI 2019 northern hemisphere permafrost dataset"; String coordinates "delta_time latitude longitude"; } /gt1r/land_segments/dem_removal_flag { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/dem_removal_flag"; String long_name "dem removal flag"; String units "1"; String source "ATBD Segment reference DEM removal flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "Flag indicating more than dem_removal_percent_limit (default 20.0) removed from land segment due to failing DEM-QA tests"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt1r/land_segments/h_dif_ref { String HDF5_OBJ_FULLPATH "/gt1r/land_segments/h_dif_ref"; Float32 _FillValue 3.402823466e+38; String long_name "h dif from reference"; String units "meters"; String source "Land ATBD segment parameters for Land Products"; String contentType "modelResult"; String description "Difference between h_te_median and ref_DEM"; String coordinates "delta_time latitude longitude"; } /gt1r/signal_photons/ { String HDF5_OBJ_FULLPATH "/gt1r/signal_photons/"; String description "Contains parameters related to individual photons."; String data_rate "Data are stored at the signal-photon classification rate."; } /gt1r/signal_photons/classed_pc_flag { String HDF5_OBJ_FULLPATH "/gt1r/signal_photons/classed_pc_flag"; String long_name "photon land atbd classification"; String units "1"; String source "Land ATBD Subgroup: Photons"; String contentType "modelResult"; String description "Land Vegetation ATBD classification flag for each photon as either noise, ground, canopy, and top of canopy. 0 = noise, 1 = ground, 2 = canopy, or 3 = top of canopy."; String coordinates "delta_time"; String flag_meanings "noise ground canopy top_of_canopy"; Int16 flag_values 0, 1, 2, 3; } /gt1r/signal_photons/classed_pc_indx { String HDF5_OBJ_FULLPATH "/gt1r/signal_photons/classed_pc_indx"; String units "1"; String long_name "indicies of classed photons"; String source "Retained from prior a_alt_science_ph packet"; String contentType "referenceInformation"; String description "Index (1-based) of the ATL08 classified signal photon from the start of the ATL03 geolocation segment specified on the ATL08 product at the photon rate in the corresponding parameter, ph_segment_id. This index traces back to specific photon within a 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group."; String coordinates "delta_time"; } /gt1r/signal_photons/ph_h { String HDF5_OBJ_FULLPATH "/gt1r/signal_photons/ph_h"; Float32 _FillValue 3.402823466e+38; String long_name "relative photon height"; String standard_name "height"; String units "meters"; String source "Land ATBD Subgroup: Photons"; String contentType "physicalMeasurement"; String description "Height of photons above interpolated land surface"; String coordinates "delta_time"; } /gt1r/signal_photons/d_flag { String HDF5_OBJ_FULLPATH "/gt1r/signal_photons/d_flag"; String long_name "dragann flag"; String units "1"; String source "Land ATBD Subgroup: Photons"; String contentType "qualityInformation"; String description "Flag indicating the labeling of DRAGANN noise filtering for a given photon."; String coordinates "delta_time"; String flag_meanings "noise signal"; Int16 flag_values 0, 1; } /gt1r/signal_photons/delta_time { String HDF5_OBJ_FULLPATH "/gt1r/signal_photons/delta_time"; String CLASS "DIMENSION_SCALE"; String NAME "delta_time"; String long_name "delta time"; String standard_name "time"; String units "seconds since 2018-01-01"; String source "ATL03"; String contentType "auxiliaryInformation"; 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."; } /gt1r/signal_photons/ph_segment_id { String HDF5_OBJ_FULLPATH "/gt1r/signal_photons/ph_segment_id"; String long_name "segment id of photon"; String units "1"; String source "Retained from prior a_alt_science_ph packet"; String contentType "referenceInformation"; String description "Segment ID of photons tracing back to specific 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the photon on ATL03 is the segment_id, orbit, and classed_pc_indx. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group."; String coordinates "delta_time"; } /gt2r/ { String HDF5_OBJ_FULLPATH "/gt2r/"; String atlas_pce "pce2"; String atlas_beam_type "weak"; String groundtrack_id "gt2r"; String atmosphere_profile "profile_2"; String atlas_spot_number "4"; String sc_orientation "Backward"; } /gt2r/land_segments/ { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/"; String description "Contains data categorized as land at 100 meter intervals."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt2r/land_segments/segment_watermask { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/segment_watermask"; String long_name "segment watermask"; String units "1"; String source "ATL08 ATBD segment_watermask"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Water mask(i.e. flag) indicating inland water as referenced from the Global Raster Water Mask(ANC33) at 250 m spatial resolution."; String coordinates "delta_time latitude longitude"; String flag_meanings "no_water water Undetermined"; Byte flag_values 0, 1, 255; } /gt2r/land_segments/delta_time_end { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/delta_time_end"; String long_name "delta time end"; String units "seconds since 2018-01-01"; String source "Derived (gps_seconds-gps_sec_offset)"; String contentType "referenceInformation"; String description "Time of the last photon contained within the data segment, in seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/latitude_20m { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/latitude_20m"; Float32 _FillValue 3.402823466e+38; String long_name "latitude of 20m segments"; String units "degree"; String source "ATBD Geosegment latitude"; Float32 valid_min -90.; Float32 valid_max 90.; String contentType "modelResult"; String description "Center latitude of 20m geosegments within each 100m land segment."; String coordinates "latitude longitude delta_time"; } /gt2r/land_segments/rgt { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/rgt"; String long_name "reference ground track"; String units "1"; String source "Operations"; Int16 valid_min 1; Int16 valid_max 1387; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt2r/land_segments/dem_flag { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/dem_flag"; String long_name "dem source flag"; String units "1"; String source "Atmosphere ATBD"; Int16 valid_min 0; Int16 valid_max 127; String contentType "referenceInformation"; String description "Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=Global, 3=MSS, 4=Antarctic."; String coordinates "delta_time latitude longitude"; String flag_meanings "none arctic global mss antarctic Undetermined"; Int16 flag_values 0, 1, 2, 3, 4, 127; } /gt2r/land_segments/msw_flag { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/msw_flag"; String long_name "multiple scattering warning flag"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 127; String contentType "qualityInformation"; String description "Multiple Scattering Warning flag. If no layers were detected, then msw_flag = 0. If blowing snow is detected and its estimated optical depth is greater than or equal to 0.5, then msw_flag = 5. If the blowing snow optical depth is less than 0.5, then msw_flag = 4. If no blowing snow is detected but there are cloud or aerosol layers detected, the msw_flag assumes values of 1 to 3 based on the height of the bottom of the lowest layer: < 1 km, msw_flag = 3; 1-3 km, msw_flag = 2; > 3km, msw_flag = 1. A value of 127 indicates that the signal to noise of the data was too low to reliably ascertain the presence of cloud or blowing snow. We expect values of 127 to occur only during daylight."; String coordinates "delta_time latitude longitude"; 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 127, 0, 1, 2, 3, 4, 5; } /gt2r/land_segments/permafrost_prob { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/permafrost_prob"; Int16 _FillValue 127; String long_name "permafrost probaility"; String standard_name "permafrost_prob"; String units "percent"; String source "ESA CCI, ANC47"; Int16 valid_min 0; Int16 valid_max 100; String contentType "referenceInformation"; String description "Permafrost probability (0 - 100) derived via percent of permafrost within pixel cell area in ESA CCI 2019 northern hemisphere permafrost dataset"; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/cloud_flag_atm { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/cloud_flag_atm"; Int16 _FillValue 127; String long_name "cloud flag atm"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 10; String contentType "qualityInformation"; String description "Cloud confidence flag from ATL09 that indicates the number of cloud or aerosol layers identified in each 25Hz atmospheric profile. If the flag is greater than 0, aerosols or clouds could be present. Valid range is 0 - 10."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/snr { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/snr"; Float32 _FillValue 3.402823466e+38; String long_name "signal to noise ratio"; String units "1"; String source "ATBD Noise filtering via DRAGANN"; String contentType "modelResult"; String description "The signal to noise ratio of geolocated photons as determined by the ratio of the superset of ATL03 signal and DRAGANN found signal photons used for processing the ATL08 segments to the background photons (i.e. noise) within the same ATL08 segments."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/canopy/ { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/"; String description "Contains height parameters based on the land algorithm."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt2r/land_segments/canopy/h_canopy { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/h_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "height canopy"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "98% height of all the individual canopy relative heights for the segment above the estimated terrain surface. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/canopy_rh_conf { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/canopy_rh_conf"; String units "1"; String long_name "canopy relative height confidence"; String source "Land/Veg ATBD Vegetation Parameters"; Int16 valid_min 0; Int16 valid_max 2; String contentType "modelResult"; String description "Canopy relative height confidence flag based on percentage of ground and canopy photons within a segment: 0 (<5% canopy), 1 (>5% canopy, <5% ground), 2 (>5% canopy, >5% ground)."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "<5%_canopy >=5%_canopy_<5%_ground >=5%_canopy_>=5%_ground"; Int16 flag_values 0, 1, 2; } /gt2r/land_segments/canopy/h_median_canopy_abs { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/h_median_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute segment median canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The median of individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/h_min_canopy { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/h_min_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "minimum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The minimum of relative individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/h_mean_canopy_abs { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/h_mean_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute mean canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Mean of the individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/h_median_canopy { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/h_median_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "median canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The median of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. This parameter should be equivalent to RH50 reported in the literature."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/h_canopy_abs { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/h_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute segment canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The 98% height of all the absolute individual canopy heights referenced above the WGS84 ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/toc_roughness { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/toc_roughness"; Float32 _FillValue 3.402823466e+38; String long_name "top of canopy roughness"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Standard deviation of the relative heights of all photons classified as top of canopy within the segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/h_min_canopy_abs { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/h_min_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute minimum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The minimum of absolute individual canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/h_dif_canopy { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/h_dif_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "canopy diff to median height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Difference between h_canopy and h_median_canopy"; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/h_canopy_quad { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/h_canopy_quad"; Float32 _FillValue 3.402823466e+38; String long_name "canopy quadratic mean"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The quadratic mean height of individual classified relative canopy photon heights above the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/h_canopy_20m { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/h_canopy_20m"; String units "m"; Float32 _FillValue 3.402823466e+38; String long_name "canopy height 20m"; String source "ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Canopy height for each 20m geosegment with each 100m land segment."; String coordinates "../latitude ../longitude ../delta_time"; } /gt2r/land_segments/canopy/n_ca_photons { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/n_ca_photons"; String long_name "number canopy photons"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The number of photons classified as canopy within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/photon_rate_can { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/photon_rate_can"; Float32 _FillValue 3.402823466e+38; String long_name "Canopy photon rate"; String units "s^-1"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Calculated photon rate of canopy photons within each 100m segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/centroid_height { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/centroid_height"; Float32 _FillValue 3.402823466e+38; String long_name "centroid height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Optical centroid of all photons classified as either canopy or ground points within the segment. The heights used in this calculation are absolute heights above the reference ellipsoid. This parameter is equivalent to the centroid height produced ICESat GLA14."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/canopy_h_metrics_abs { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/canopy_h_metrics_abs"; Float32 _FillValue 3.402823466e+38; String long_name "canopy absolute height metrics"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Height metrics based on the cumulative distribution of absolute canopy heights above the WGS84 Ellipsoid. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/can_noise { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/can_noise"; Float32 _FillValue 3.402823466e+38; String long_name "canopy noise rate"; String units "count/meter"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Number of noise photons calculated that fall within the canopy height for each 100 m segment based on ATL03 background rate parameters."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/h_mean_canopy { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/h_mean_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "mean canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Mean of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/subset_can_flag { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/subset_can_flag"; Int16 _FillValue 127; String long_name "subset canopy flag"; String units "1"; String source "Land ATBD Vegetation Parameters"; Int16 valid_min -1; Int16 valid_max 1; String contentType "modelResult"; String description "Quality flag indicating the canopy photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "no_photon_data_within_geosegment no_canopy_photons_within_geosegment canopy_photons_present_within_geosegment"; Int16 flag_values -1, 0, 1; } /gt2r/land_segments/canopy/canopy_h_metrics { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/canopy_h_metrics"; Float32 _FillValue 3.402823466e+38; String long_name "canopy height metrics"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Height metrics based on the cumulative distribution of relative canopy heights above the interpolated ground surface. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/n_toc_photons { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/n_toc_photons"; String long_name "number top of canopy photons"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The number of photons classified as top of canopy within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/h_max_canopy_abs { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/h_max_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute maximum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Maximum of individual absolute canopy heights within segment referenced above the WGS84 ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/h_canopy_uncertainty { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/h_canopy_uncertainty"; Float32 _FillValue 3.402823466e+38; String long_name "segment canopy height uncertainty"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "qualityInformation"; String description "Uncertainty of the relative canopy heights for the segment. Incorporates all systematic uncertainties as well as uncertainty from errors of identified photons. See section 1 and equations 1.4 and 1.5 of the ATL08 ATBD."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/photon_rate_can_nr { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/photon_rate_can_nr"; Float32 _FillValue 3.402823466e+38; String long_name "noise reduced number of canopy photons"; String units "s^-1"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Noise removed photon canopy rate within each 100 m segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/can_quality_score { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/can_quality_score"; String units "1"; String source "Land ATBD Vegetation Parameters"; Int16 valid_min 0; Int16 valid_max 100; String contentType "modelResult"; String description "Canopy quality score based on coincident conditions, from ATL08 ATBD section titled \"Canopy Quality Score\"."; String coordinates "../delta_time ../latitude ../longitude"; Int16 _FillValue 127; String long_name "canopy quality score"; } /gt2r/land_segments/canopy/canopy_openness { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/canopy_openness"; Float32 _FillValue 3.402823466e+38; String long_name "canopy openness"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Standard Deviation of all photons classified as canopy photons within the segment to provide inference of canopy openness."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/h_max_canopy { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/h_max_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "maximum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Relative maximum of individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. Should be equivalent to RH100 metric reported in the literature."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/canopy/segment_cover { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/canopy/segment_cover"; Int16 _FillValue 32767; String long_name "canopy cover percentage"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Average percentage value of the valid (value <= 100) Copernicus fractional cover product for each 100 m segment. This data is temporally static, and is the summation of forest and shrub land cover fractions. Source data from: https://land.copernicus.eu/en/products/global-dynamic-land-cover/copernicus-global-land-service-land-cover-100m-collection-3-epoch-2019-globe ."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/sigma_across { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/sigma_across"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas y"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Total cross-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_across. Sigma_atlas_y is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/terrain/ { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/"; String description "Contains terrain parameters at a 100m aggregation."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt2r/land_segments/terrain/h_te_uncertainty { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/h_te_uncertainty"; Float32 _FillValue 3.402823466e+38; String long_name "uncertainty of h_te_mean"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Uncertainty of the mean terrain height for the segment. This uncertainty incorporates all systematic uncertainties(e.g. timing orbits, geolocation,etc.) as well as uncertainty from errors of identified photons. This parameter is described in section 1, equation 1.4 in ATL08 ATBD."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/terrain/h_te_mean { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/h_te_mean"; Float32 _FillValue 3.402823466e+38; String long_name "mean terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The mean of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/terrain/h_te_min { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/h_te_min"; Float32 _FillValue 3.402823466e+38; String long_name "minimum terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The minimum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/terrain/photon_rate_te { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/photon_rate_te"; Float32 _FillValue 3.402823466e+38; String long_name "Terrain photon rate"; String units "s^-1"; String source "Land ATBD Land Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Calculated photon rate of terrain photons within each 100m segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/terrain/h_te_interp { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/h_te_interp"; Float32 _FillValue 3.402823466e+38; String long_name "interpolated terrain surface height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Interpolated terrain surface height above the WGS84 Ellipsoid at the midpoint of the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/terrain/h_te_max { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/h_te_max"; Float32 _FillValue 3.402823466e+38; String long_name "maximum terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The maximum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/terrain/h_te_rh25 { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/h_te_rh25"; String units "meters"; Float32 _FillValue 3.402823466e+38; String long_name "Terrain height 25% percentile"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The terrain elevation from the 25% height. The classified ground photons are sorted into a cumulative distribution and the height associated with the 25% height for that segment is reported."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/terrain/h_te_skew { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/h_te_skew"; Float32 _FillValue 3.402823466e+38; String long_name "skew of terrain heights"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The skewness of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/terrain/h_te_best_fit_20m { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/h_te_best_fit_20m"; Float32 _FillValue 3.402823466e+38; String long_name "best fit 20m"; String units "m"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Best fit terrain height to center of each 20m geosegment within each 100m land segment."; String coordinates "../latitude ../longitude ../delta_time"; } /gt2r/land_segments/terrain/h_te_median { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/h_te_median"; Float32 _FillValue 3.402823466e+38; String long_name "median terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The median of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/terrain/h_te_best_fit { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/h_te_best_fit"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain height best fit"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The best fit terrain elevation at the the mid-point location of each 100m segment. The mid-segment terrain elevation is determined by selecting the best of three fits- linear, 3rd order and 4th order polynomials - to the terrain photons and interpolating the elevation at the mid-point location of the 100 m segment. For the linear fit, a slope correction and weighting is applied to each ground photon based on the distance to the slope height at the center of the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/terrain/h_te_std { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/h_te_std"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain roughness"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The standard deviation of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/terrain/terrain_slope { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/terrain_slope"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain slope"; String units "1"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The along-track slope of terrain, within each segment;computed by a linear fit of terrain classified photons. Slope is in units of delta height over delta along track distance."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/terrain/subset_te_flag { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/subset_te_flag"; Int16 _FillValue 127; String long_name "subset terrain flag"; String units "1"; String source "Land ATBD Land Parameters"; Int16 valid_min -1; Int16 valid_max 1; String contentType "modelResult"; String description "Quality flag indicating the terrain photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "no_photon_data_within_geosegment no_terrain_photons_within_geosegment terrain_photons_present_within_geosegment"; Int16 flag_values -1, 0, 1; } /gt2r/land_segments/terrain/n_te_photons { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/n_te_photons"; String long_name "number of ground photons"; String units "1"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The number of the photons classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/terrain/h_te_mode { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/h_te_mode"; Float32 _FillValue 3.402823466e+38; String long_name "mode of terrain heights"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The mode of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/terrain/te_quality_score { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain/te_quality_score"; Int16 _FillValue 127; String long_name "terrain quality score"; String units "1"; String source "Land ATBD Land Parameters"; Int16 valid_min 0; Int16 valid_max 100; String contentType "modelResult"; String description "Quality score based on coincident conditions, from ATL08 ATBD section titled \"Terrain Quality Score\"."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2r/land_segments/layer_flag { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/layer_flag"; String long_name "consolidated cloud flag"; String units "1"; String source "ATL09"; String contentType "modelResult"; 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 coordinates "delta_time latitude longitude"; String flag_meanings "likely_clear likely_cloudy"; Int16 flag_values 0, 1; } /gt2r/land_segments/segment_snowcover { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/segment_snowcover"; String long_name "segment snowcover"; String units "1"; String source "ATL08 ATBD segment_snowcover"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Daily snow/ice cover from ATL09 at the 25 Hz rate(275m) indicating likely presence of snow and ice within each segment. 0=ice free water; 1=snow free land; 2=snow; 3=ice."; String coordinates "delta_time latitude longitude"; String flag_meanings "ice_free_water snow_free_land snow ice Undetermined"; Byte flag_values 0, 1, 2, 3, 255; } /gt2r/land_segments/beam_azimuth { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/beam_azimuth"; Float32 _FillValue 3.402823466e+38; String long_name "beam azimuth"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; String description "Azimuth(in radians) of the unit pointing vector for the reference photon in the local ENU frame in radians. The angle is measured from north and positive towards East."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/solar_azimuth { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/solar_azimuth"; String long_name "solar azimuth"; String units "degrees_east"; String source "ATL03 ATBD"; String contentType "referenceInformation"; String description "The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/psf_flag { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/psf_flag"; String long_name "point spread function flag"; String units "1"; String source "Land/Veg ATBD Refine Ground Estimates"; Byte valid_min 0; Byte valid_max 255; String contentType "referenceInformation"; String description "Flag is set to 1 if the point spread function (computed as sigma_atlas_land) has exceeded the threshold (1 m)"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt2r/land_segments/longitude { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/longitude"; String long_name "longitude"; String standard_name "longitude"; String units "degrees"; String source "Land ATBD segment parameters for Land Products"; Float32 valid_min -180.; Float32 valid_max 180.; String contentType "modelResult"; String description "Longitude of the center-most signal photon within each segment."; String coordinates "delta_time latitude"; } /gt2r/land_segments/latitude { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/latitude"; String long_name "latitude"; String standard_name "latitude"; String units "degrees"; String source "Land ATBD segment parameters for Land Products"; Float32 valid_min -90.; Float32 valid_max 90.; String contentType "modelResult"; String description "Latitude of the center-most signal photon within each segment."; String coordinates "delta_time longitude"; } /gt2r/land_segments/segment_id_end { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/segment_id_end"; String long_name "end geolocation segment bin"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Geolocation segment number of the last photon in the land segment."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/longitude_20m { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/longitude_20m"; Float32 _FillValue 3.402823466e+38; String long_name "longitude of 20m segments"; String units "degree"; String source "ATBD Geosegment longitude"; Float32 valid_min -180.; Float32 valid_max 180.; String contentType "modelResult"; String description "Center longitude of 20m geosegments within each 100m land segment."; String coordinates "latitude longitude delta_time"; } /gt2r/land_segments/surf_type { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/surf_type"; String long_name "surface type"; String units "1"; String source "ATL03 ATBD"; Int16 valid_min 0; Int16 valid_max 1; String contentType "referenceInformation"; String description "Flags describing which surface types this interval is associated with. 0=not type, 1=is type. Order of array is land, ocean, sea ice, land ice, inland water."; String coordinates "delta_time latitude longitude"; String flag_meanings "not_type is_type"; Int16 flag_values 0, 1; } /gt2r/land_segments/brightness_flag { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/brightness_flag"; String long_name "brightness flag"; String units "1"; String source "Land ATBD Brightness_flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "Flag indicating that the ground surface is bright (e.g. snow-covered or other bright surfaces)"; String coordinates "delta_time latitude longitude"; String flag_meanings "not_bright_surface bright_surface Undetermined"; Byte flag_values 0, 1, 255; } /gt2r/land_segments/segment_landcover { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/segment_landcover"; String long_name "segment landcover"; String units "1"; String source "ATL08 ATBD segment_landcover"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "UN-FAO Land Cover Surface type classification as reference from Copernicus Land Cover(ANC18) at the 100m resolution."; String coordinates "delta_time latitude longitude"; String flag_meanings "No_data Closed_forest_evergreen_needle_leaf Closed_forest_deciduous_needle_leaf Closed_forest_evergreen_broad_leaf Closed_forest_deciduous_broad_leaf Closed_forest_mixed Closed_forest_unknown Open_forest_evergreen_needle_leaf Open_forest_deciduous_needle_leaf Open_forest_evergreen_broad_leaf Open_forest_deciduous_broad_leaf Open_forest_mixed Open_forest_unknown Shrubs Herbaceous Herbaceous_wetleand Moss_and_lichen Bare_sparse_vegetation Cultivated_and_managed_vegetation_agriculture Urban_built_up Snow_and_ice Permanent_water_bodies Open_sea Undetermined"; Byte flag_values 0, 111, 113, 112, 114, 115, 116, 121, 123, 122, 124, 125, 126, 20, 30, 90, 100, 60, 40, 50, 70, 80, 200, 255; } /gt2r/land_segments/ph_removal_flag { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/ph_removal_flag"; String long_name "ph removal flag"; String units "1"; String source "ATBD Final photon classification QA"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Flag indicating more than ph_removal_percent_limit (default 50.0) removed from land segment due to failing QA tests"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt2r/land_segments/asr { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/asr"; Float32 _FillValue 3.402823466e+38; String long_name "apparent surface reflectance"; String units "1"; String source "ATL09"; String contentType "auxiliaryInformation"; String description "Apparent surface reflectance"; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/sigma_atlas_land { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/sigma_atlas_land"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas land"; String units "1"; String source "Land ATBD Refine Ground Estimates"; String contentType "referenceInformation"; String description "Total vertical geolocation error due to ranging and local surface slope. The parameter is computed for ATL08 as described in equation 1.2 ATL08 ATBD."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/segment_id_beg { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/segment_id_beg"; String long_name "begin geolocation segment bin"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Geolocation segment number of the first photon in the land segment."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/sigma_along { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/sigma_along"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas x"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Total along-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_along. Sigma_atlas_x is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/dem_h { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/dem_h"; Float32 _FillValue 3.402823466e+38; String long_name "dem height"; String units "meters"; String source "Arctic, Antarctic, Global, MSS DEM"; String contentType "referenceInformation"; String description "Best available DEM (in priority of Arctic/Antarctic/Global/MSS) value at the geolocation point. Height is in meters above the WGS84 Ellipsoid."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/beam_coelev { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/beam_coelev"; Float32 _FillValue 3.402823466e+38; String long_name "beam co-elevation"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt2r/land_segments/sat_flag { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/sat_flag"; String long_name "saturation flag"; String units "1"; String source "ATL03, Land ATBD Saturation Flag"; Int16 valid_min -1; Int16 valid_max 127; String contentType "auxiliaryInformation"; String description "Flag derived from full_sat_fract on the ATL03 data product, averaged over 5 geosegments in 100m land segment"; String coordinates "delta_time latitude longitude"; String flag_meanings "no_saturation_detected saturation_detected not_enough_valid_data Undetermined"; Int16 flag_values 0, 1, -1, 127; } /gt2r/land_segments/sigma_topo { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/sigma_topo"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas topo"; String units "1"; String source "Land ATBD Refine Ground Estimates"; String contentType "referenceInformation"; String description "Total uncertainty that include sigma_h plus geolocation uncertainty due to local slope (equation 1.3). The local slope is multiplied by the geolocation uncertainty factor. This will be used to determine the total vertical geolocation error due to ranging and local slope."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/night_flag { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/night_flag"; String long_name "night flag"; String units "1"; String source "Land ATBD Night_Flag"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Flag indicating the data were acquired in night conditions: 0=day, 1=night. Flag is derived from solar elevation at the geolocated segment. IF solar elevation is above threshold it is day, if not then it is night. Threshold is set in atlas_l3a_const_mod."; String coordinates "delta_time latitude longitude"; String flag_meanings "day night Undetermined"; Byte flag_values 0, 1, 255; } /gt2r/land_segments/delta_time_beg { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/delta_time_beg"; String long_name "delta time begin"; String units "seconds since 2018-01-01"; String source "Derived (gps_seconds-gps_sec_offset)"; String contentType "referenceInformation"; String description "Time of the first photon contained within the data segment, in seconds since the ATLAS SDP GPS Epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/sigma_h { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/sigma_h"; Float32 _FillValue 3.402823466e+38; String long_name "height uncertainty"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m) provided at the geolocation segment rate on ATL03. Sigma_h is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/last_seg_extend { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/last_seg_extend"; String long_name "last segment extended"; String standard_name "last_seg_extend"; String units "kilometers"; String source "Land ATBD Preparing ATL03 data for input"; String contentType "auxiliaryInformation"; String description "The distance (km) that the last ATL08 processing segment in a file is either extended or overlapped with the previous ATL08 processing segment."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/column_od_asr { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/column_od_asr"; Float32 _FillValue 3.402823466e+38; String long_name "Column optical depth from ASR"; String units "1"; String source "ATL09"; String contentType "auxiliaryInformation"; String description "Optical depth of atmosphere column based on apparent surface reflectance and the assumed actual surface reflectance."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/atlas_pa { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/atlas_pa"; Float32 _FillValue 3.402823466e+38; String long_name "atlas pointing angle"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; String description "Off nadir pointing angle (in radians) of the satellite to increase spatial sampling in the non-polar regions. ATLAS_PA =radians(90degs-beam_coelev)."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/ph_ndx_beg { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/ph_ndx_beg"; String long_name "photon index begin"; String units "1"; String source "Derived"; String contentType "auxiliaryInformation"; String description "Index (1-based) within the photon-rate data (/land_segments/photons) of the first photon within this each land segment."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/solar_elevation { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/solar_elevation"; String long_name "solar elevation"; String units "degrees"; String source "ATL03 ATBD"; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt2r/land_segments/delta_time { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/delta_time"; String CLASS "DIMENSION_SCALE"; String long_name "mean_pass_time"; String standard_name "time"; String units "seconds since 2018-01-01"; String source "Land ATBD segment parameters for Land Products"; String contentType "referenceInformation"; String description "Mean time for the segment in number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "latitude longitude"; String NAME "delta_time"; } /gt2r/land_segments/cloud_fold_flag { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/cloud_fold_flag"; String long_name "cloud folding flag"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 127; String contentType "modelResult"; String description "Flag that indicates this profile likely contains cloud signal folded down from above 15 km to the last 2-3 km of the profile. See ATL09 ATBD Table 3.9 for detailed flag value meanings."; String coordinates "delta_time latitude longitude"; String flag_meanings "no_folding goes5_indicates profile_indicates both_indicate outside_limits"; Int16 flag_values 0, 1, 2, 3, 127; } /gt2r/land_segments/n_seg_ph { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/n_seg_ph"; String long_name "number of photons"; String units "1"; String source "Derived"; String contentType "auxiliaryInformation"; String description "Number of photons within each land segment."; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/terrain_flg { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/terrain_flg"; String long_name "terrain flag"; String units "1"; String source "Land ATBD Segment_terrain flag"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Terrain flag quality check to indicate a deviation above a threshold from the reference DEM height reported on the product."; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt2r/land_segments/urban_flag { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/urban_flag"; String long_name "segment urban flag"; String units "1"; String source "Land ATBD Urban_flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "The urban flag indicates that a segment is likely located over an urban area as determined by coincident pixels in the Global Urban Footprint (GUF) 0.4 arcsecond product."; String coordinates "delta_time latitude longitude"; String flag_meanings "not_urban urban Undetermined"; Byte flag_values 0, 1, 255; } /gt2r/land_segments/permafrost_alt { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/permafrost_alt"; Float32 _FillValue 3.402823466e+38; String long_name "permafrost active layer thickness"; String standard_name "permafrost_alt"; String units "meters"; String source "ESA CCI, ANC47"; Float32 valid_min 0.; Float32 valid_max 100.; String contentType "referenceInformation"; String description "Permafrost active layer thickness (m) from ESA CCI 2019 northern hemisphere permafrost dataset"; String coordinates "delta_time latitude longitude"; } /gt2r/land_segments/dem_removal_flag { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/dem_removal_flag"; String long_name "dem removal flag"; String units "1"; String source "ATBD Segment reference DEM removal flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "Flag indicating more than dem_removal_percent_limit (default 20.0) removed from land segment due to failing DEM-QA tests"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt2r/land_segments/h_dif_ref { String HDF5_OBJ_FULLPATH "/gt2r/land_segments/h_dif_ref"; Float32 _FillValue 3.402823466e+38; String long_name "h dif from reference"; String units "meters"; String source "Land ATBD segment parameters for Land Products"; String contentType "modelResult"; String description "Difference between h_te_median and ref_DEM"; String coordinates "delta_time latitude longitude"; } /gt2r/signal_photons/ { String HDF5_OBJ_FULLPATH "/gt2r/signal_photons/"; String description "Contains parameters related to individual photons."; String data_rate "Data are stored at the signal-photon classification rate."; } /gt2r/signal_photons/classed_pc_flag { String HDF5_OBJ_FULLPATH "/gt2r/signal_photons/classed_pc_flag"; String long_name "photon land atbd classification"; String units "1"; String source "Land ATBD Subgroup: Photons"; String contentType "modelResult"; String description "Land Vegetation ATBD classification flag for each photon as either noise, ground, canopy, and top of canopy. 0 = noise, 1 = ground, 2 = canopy, or 3 = top of canopy."; String coordinates "delta_time"; String flag_meanings "noise ground canopy top_of_canopy"; Int16 flag_values 0, 1, 2, 3; } /gt2r/signal_photons/classed_pc_indx { String HDF5_OBJ_FULLPATH "/gt2r/signal_photons/classed_pc_indx"; String units "1"; String long_name "indicies of classed photons"; String source "Retained from prior a_alt_science_ph packet"; String contentType "referenceInformation"; String description "Index (1-based) of the ATL08 classified signal photon from the start of the ATL03 geolocation segment specified on the ATL08 product at the photon rate in the corresponding parameter, ph_segment_id. This index traces back to specific photon within a 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group."; String coordinates "delta_time"; } /gt2r/signal_photons/ph_h { String HDF5_OBJ_FULLPATH "/gt2r/signal_photons/ph_h"; Float32 _FillValue 3.402823466e+38; String long_name "relative photon height"; String standard_name "height"; String units "meters"; String source "Land ATBD Subgroup: Photons"; String contentType "physicalMeasurement"; String description "Height of photons above interpolated land surface"; String coordinates "delta_time"; } /gt2r/signal_photons/d_flag { String HDF5_OBJ_FULLPATH "/gt2r/signal_photons/d_flag"; String long_name "dragann flag"; String units "1"; String source "Land ATBD Subgroup: Photons"; String contentType "qualityInformation"; String description "Flag indicating the labeling of DRAGANN noise filtering for a given photon."; String coordinates "delta_time"; String flag_meanings "noise signal"; Int16 flag_values 0, 1; } /gt2r/signal_photons/delta_time { String HDF5_OBJ_FULLPATH "/gt2r/signal_photons/delta_time"; String CLASS "DIMENSION_SCALE"; String NAME "delta_time"; String long_name "delta time"; String standard_name "time"; String units "seconds since 2018-01-01"; String source "ATL03"; String contentType "auxiliaryInformation"; 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."; } /gt2r/signal_photons/ph_segment_id { String HDF5_OBJ_FULLPATH "/gt2r/signal_photons/ph_segment_id"; String long_name "segment id of photon"; String units "1"; String source "Retained from prior a_alt_science_ph packet"; String contentType "referenceInformation"; String description "Segment ID of photons tracing back to specific 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the photon on ATL03 is the segment_id, orbit, and classed_pc_indx. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group."; String coordinates "delta_time"; } /gt1l/ { String HDF5_OBJ_FULLPATH "/gt1l/"; String atlas_pce "pce1"; String atlas_beam_type "strong"; String groundtrack_id "gt1l"; String atmosphere_profile "profile_1"; String atlas_spot_number "1"; String sc_orientation "Backward"; } /gt1l/land_segments/ { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/"; String description "Contains data categorized as land at 100 meter intervals."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt1l/land_segments/segment_watermask { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/segment_watermask"; String long_name "segment watermask"; String units "1"; String source "ATL08 ATBD segment_watermask"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Water mask(i.e. flag) indicating inland water as referenced from the Global Raster Water Mask(ANC33) at 250 m spatial resolution."; String coordinates "delta_time latitude longitude"; String flag_meanings "no_water water Undetermined"; Byte flag_values 0, 1, 255; } /gt1l/land_segments/delta_time_end { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/delta_time_end"; String long_name "delta time end"; String units "seconds since 2018-01-01"; String source "Derived (gps_seconds-gps_sec_offset)"; String contentType "referenceInformation"; String description "Time of the last photon contained within the data segment, in seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/latitude_20m { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/latitude_20m"; Float32 _FillValue 3.402823466e+38; String long_name "latitude of 20m segments"; String units "degree"; String source "ATBD Geosegment latitude"; Float32 valid_min -90.; Float32 valid_max 90.; String contentType "modelResult"; String description "Center latitude of 20m geosegments within each 100m land segment."; String coordinates "latitude longitude delta_time"; } /gt1l/land_segments/rgt { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/rgt"; String long_name "reference ground track"; String units "1"; String source "Operations"; Int16 valid_min 1; Int16 valid_max 1387; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt1l/land_segments/dem_flag { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/dem_flag"; String long_name "dem source flag"; String units "1"; String source "Atmosphere ATBD"; Int16 valid_min 0; Int16 valid_max 127; String contentType "referenceInformation"; String description "Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=Global, 3=MSS, 4=Antarctic."; String coordinates "delta_time latitude longitude"; String flag_meanings "none arctic global mss antarctic Undetermined"; Int16 flag_values 0, 1, 2, 3, 4, 127; } /gt1l/land_segments/msw_flag { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/msw_flag"; String long_name "multiple scattering warning flag"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 127; String contentType "qualityInformation"; String description "Multiple Scattering Warning flag. If no layers were detected, then msw_flag = 0. If blowing snow is detected and its estimated optical depth is greater than or equal to 0.5, then msw_flag = 5. If the blowing snow optical depth is less than 0.5, then msw_flag = 4. If no blowing snow is detected but there are cloud or aerosol layers detected, the msw_flag assumes values of 1 to 3 based on the height of the bottom of the lowest layer: < 1 km, msw_flag = 3; 1-3 km, msw_flag = 2; > 3km, msw_flag = 1. A value of 127 indicates that the signal to noise of the data was too low to reliably ascertain the presence of cloud or blowing snow. We expect values of 127 to occur only during daylight."; String coordinates "delta_time latitude longitude"; 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 127, 0, 1, 2, 3, 4, 5; } /gt1l/land_segments/permafrost_prob { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/permafrost_prob"; Int16 _FillValue 127; String long_name "permafrost probaility"; String standard_name "permafrost_prob"; String units "percent"; String source "ESA CCI, ANC47"; Int16 valid_min 0; Int16 valid_max 100; String contentType "referenceInformation"; String description "Permafrost probability (0 - 100) derived via percent of permafrost within pixel cell area in ESA CCI 2019 northern hemisphere permafrost dataset"; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/cloud_flag_atm { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/cloud_flag_atm"; Int16 _FillValue 127; String long_name "cloud flag atm"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 10; String contentType "qualityInformation"; String description "Cloud confidence flag from ATL09 that indicates the number of cloud or aerosol layers identified in each 25Hz atmospheric profile. If the flag is greater than 0, aerosols or clouds could be present. Valid range is 0 - 10."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/snr { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/snr"; Float32 _FillValue 3.402823466e+38; String long_name "signal to noise ratio"; String units "1"; String source "ATBD Noise filtering via DRAGANN"; String contentType "modelResult"; String description "The signal to noise ratio of geolocated photons as determined by the ratio of the superset of ATL03 signal and DRAGANN found signal photons used for processing the ATL08 segments to the background photons (i.e. noise) within the same ATL08 segments."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/canopy/ { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/"; String description "Contains height parameters based on the land algorithm."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt1l/land_segments/canopy/h_canopy { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/h_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "height canopy"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "98% height of all the individual canopy relative heights for the segment above the estimated terrain surface. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/canopy_rh_conf { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/canopy_rh_conf"; String units "1"; String long_name "canopy relative height confidence"; String source "Land/Veg ATBD Vegetation Parameters"; Int16 valid_min 0; Int16 valid_max 2; String contentType "modelResult"; String description "Canopy relative height confidence flag based on percentage of ground and canopy photons within a segment: 0 (<5% canopy), 1 (>5% canopy, <5% ground), 2 (>5% canopy, >5% ground)."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "<5%_canopy >=5%_canopy_<5%_ground >=5%_canopy_>=5%_ground"; Int16 flag_values 0, 1, 2; } /gt1l/land_segments/canopy/h_median_canopy_abs { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/h_median_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute segment median canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The median of individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/h_min_canopy { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/h_min_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "minimum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The minimum of relative individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/h_mean_canopy_abs { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/h_mean_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute mean canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Mean of the individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/h_median_canopy { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/h_median_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "median canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The median of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. This parameter should be equivalent to RH50 reported in the literature."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/h_canopy_abs { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/h_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute segment canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The 98% height of all the absolute individual canopy heights referenced above the WGS84 ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/toc_roughness { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/toc_roughness"; Float32 _FillValue 3.402823466e+38; String long_name "top of canopy roughness"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Standard deviation of the relative heights of all photons classified as top of canopy within the segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/h_min_canopy_abs { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/h_min_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute minimum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The minimum of absolute individual canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/h_dif_canopy { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/h_dif_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "canopy diff to median height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Difference between h_canopy and h_median_canopy"; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/h_canopy_quad { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/h_canopy_quad"; Float32 _FillValue 3.402823466e+38; String long_name "canopy quadratic mean"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The quadratic mean height of individual classified relative canopy photon heights above the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/h_canopy_20m { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/h_canopy_20m"; String units "m"; Float32 _FillValue 3.402823466e+38; String long_name "canopy height 20m"; String source "ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Canopy height for each 20m geosegment with each 100m land segment."; String coordinates "../latitude ../longitude ../delta_time"; } /gt1l/land_segments/canopy/n_ca_photons { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/n_ca_photons"; String long_name "number canopy photons"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The number of photons classified as canopy within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/photon_rate_can { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/photon_rate_can"; Float32 _FillValue 3.402823466e+38; String long_name "Canopy photon rate"; String units "s^-1"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Calculated photon rate of canopy photons within each 100m segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/centroid_height { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/centroid_height"; Float32 _FillValue 3.402823466e+38; String long_name "centroid height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Optical centroid of all photons classified as either canopy or ground points within the segment. The heights used in this calculation are absolute heights above the reference ellipsoid. This parameter is equivalent to the centroid height produced ICESat GLA14."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/canopy_h_metrics_abs { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/canopy_h_metrics_abs"; Float32 _FillValue 3.402823466e+38; String long_name "canopy absolute height metrics"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Height metrics based on the cumulative distribution of absolute canopy heights above the WGS84 Ellipsoid. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/can_noise { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/can_noise"; Float32 _FillValue 3.402823466e+38; String long_name "canopy noise rate"; String units "count/meter"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Number of noise photons calculated that fall within the canopy height for each 100 m segment based on ATL03 background rate parameters."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/h_mean_canopy { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/h_mean_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "mean canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Mean of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/subset_can_flag { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/subset_can_flag"; Int16 _FillValue 127; String long_name "subset canopy flag"; String units "1"; String source "Land ATBD Vegetation Parameters"; Int16 valid_min -1; Int16 valid_max 1; String contentType "modelResult"; String description "Quality flag indicating the canopy photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "no_photon_data_within_geosegment no_canopy_photons_within_geosegment canopy_photons_present_within_geosegment"; Int16 flag_values -1, 0, 1; } /gt1l/land_segments/canopy/canopy_h_metrics { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/canopy_h_metrics"; Float32 _FillValue 3.402823466e+38; String long_name "canopy height metrics"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Height metrics based on the cumulative distribution of relative canopy heights above the interpolated ground surface. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/n_toc_photons { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/n_toc_photons"; String long_name "number top of canopy photons"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The number of photons classified as top of canopy within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/h_max_canopy_abs { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/h_max_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute maximum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Maximum of individual absolute canopy heights within segment referenced above the WGS84 ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/h_canopy_uncertainty { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/h_canopy_uncertainty"; Float32 _FillValue 3.402823466e+38; String long_name "segment canopy height uncertainty"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "qualityInformation"; String description "Uncertainty of the relative canopy heights for the segment. Incorporates all systematic uncertainties as well as uncertainty from errors of identified photons. See section 1 and equations 1.4 and 1.5 of the ATL08 ATBD."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/photon_rate_can_nr { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/photon_rate_can_nr"; Float32 _FillValue 3.402823466e+38; String long_name "noise reduced number of canopy photons"; String units "s^-1"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Noise removed photon canopy rate within each 100 m segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/can_quality_score { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/can_quality_score"; String units "1"; String source "Land ATBD Vegetation Parameters"; Int16 valid_min 0; Int16 valid_max 100; String contentType "modelResult"; String description "Canopy quality score based on coincident conditions, from ATL08 ATBD section titled \"Canopy Quality Score\"."; String coordinates "../delta_time ../latitude ../longitude"; Int16 _FillValue 127; String long_name "canopy quality score"; } /gt1l/land_segments/canopy/canopy_openness { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/canopy_openness"; Float32 _FillValue 3.402823466e+38; String long_name "canopy openness"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Standard Deviation of all photons classified as canopy photons within the segment to provide inference of canopy openness."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/h_max_canopy { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/h_max_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "maximum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Relative maximum of individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. Should be equivalent to RH100 metric reported in the literature."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/canopy/segment_cover { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/canopy/segment_cover"; Int16 _FillValue 32767; String long_name "canopy cover percentage"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Average percentage value of the valid (value <= 100) Copernicus fractional cover product for each 100 m segment. This data is temporally static, and is the summation of forest and shrub land cover fractions. Source data from: https://land.copernicus.eu/en/products/global-dynamic-land-cover/copernicus-global-land-service-land-cover-100m-collection-3-epoch-2019-globe ."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/sigma_across { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/sigma_across"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas y"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Total cross-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_across. Sigma_atlas_y is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/terrain/ { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/"; String description "Contains terrain parameters at a 100m aggregation."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt1l/land_segments/terrain/h_te_uncertainty { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/h_te_uncertainty"; Float32 _FillValue 3.402823466e+38; String long_name "uncertainty of h_te_mean"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Uncertainty of the mean terrain height for the segment. This uncertainty incorporates all systematic uncertainties(e.g. timing orbits, geolocation,etc.) as well as uncertainty from errors of identified photons. This parameter is described in section 1, equation 1.4 in ATL08 ATBD."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/terrain/h_te_mean { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/h_te_mean"; Float32 _FillValue 3.402823466e+38; String long_name "mean terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The mean of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/terrain/h_te_min { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/h_te_min"; Float32 _FillValue 3.402823466e+38; String long_name "minimum terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The minimum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/terrain/photon_rate_te { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/photon_rate_te"; Float32 _FillValue 3.402823466e+38; String long_name "Terrain photon rate"; String units "s^-1"; String source "Land ATBD Land Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Calculated photon rate of terrain photons within each 100m segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/terrain/h_te_interp { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/h_te_interp"; Float32 _FillValue 3.402823466e+38; String long_name "interpolated terrain surface height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Interpolated terrain surface height above the WGS84 Ellipsoid at the midpoint of the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/terrain/h_te_max { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/h_te_max"; Float32 _FillValue 3.402823466e+38; String long_name "maximum terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The maximum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/terrain/h_te_rh25 { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/h_te_rh25"; String units "meters"; Float32 _FillValue 3.402823466e+38; String long_name "Terrain height 25% percentile"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The terrain elevation from the 25% height. The classified ground photons are sorted into a cumulative distribution and the height associated with the 25% height for that segment is reported."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/terrain/h_te_skew { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/h_te_skew"; Float32 _FillValue 3.402823466e+38; String long_name "skew of terrain heights"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The skewness of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/terrain/h_te_best_fit_20m { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/h_te_best_fit_20m"; Float32 _FillValue 3.402823466e+38; String long_name "best fit 20m"; String units "m"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Best fit terrain height to center of each 20m geosegment within each 100m land segment."; String coordinates "../latitude ../longitude ../delta_time"; } /gt1l/land_segments/terrain/h_te_median { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/h_te_median"; Float32 _FillValue 3.402823466e+38; String long_name "median terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The median of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/terrain/h_te_best_fit { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/h_te_best_fit"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain height best fit"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The best fit terrain elevation at the the mid-point location of each 100m segment. The mid-segment terrain elevation is determined by selecting the best of three fits- linear, 3rd order and 4th order polynomials - to the terrain photons and interpolating the elevation at the mid-point location of the 100 m segment. For the linear fit, a slope correction and weighting is applied to each ground photon based on the distance to the slope height at the center of the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/terrain/h_te_std { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/h_te_std"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain roughness"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The standard deviation of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/terrain/terrain_slope { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/terrain_slope"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain slope"; String units "1"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The along-track slope of terrain, within each segment;computed by a linear fit of terrain classified photons. Slope is in units of delta height over delta along track distance."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/terrain/subset_te_flag { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/subset_te_flag"; Int16 _FillValue 127; String long_name "subset terrain flag"; String units "1"; String source "Land ATBD Land Parameters"; Int16 valid_min -1; Int16 valid_max 1; String contentType "modelResult"; String description "Quality flag indicating the terrain photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "no_photon_data_within_geosegment no_terrain_photons_within_geosegment terrain_photons_present_within_geosegment"; Int16 flag_values -1, 0, 1; } /gt1l/land_segments/terrain/n_te_photons { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/n_te_photons"; String long_name "number of ground photons"; String units "1"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The number of the photons classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/terrain/h_te_mode { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/h_te_mode"; Float32 _FillValue 3.402823466e+38; String long_name "mode of terrain heights"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The mode of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/terrain/te_quality_score { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain/te_quality_score"; Int16 _FillValue 127; String long_name "terrain quality score"; String units "1"; String source "Land ATBD Land Parameters"; Int16 valid_min 0; Int16 valid_max 100; String contentType "modelResult"; String description "Quality score based on coincident conditions, from ATL08 ATBD section titled \"Terrain Quality Score\"."; String coordinates "../delta_time ../latitude ../longitude"; } /gt1l/land_segments/layer_flag { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/layer_flag"; String long_name "consolidated cloud flag"; String units "1"; String source "ATL09"; String contentType "modelResult"; 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 coordinates "delta_time latitude longitude"; String flag_meanings "likely_clear likely_cloudy"; Int16 flag_values 0, 1; } /gt1l/land_segments/segment_snowcover { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/segment_snowcover"; String long_name "segment snowcover"; String units "1"; String source "ATL08 ATBD segment_snowcover"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Daily snow/ice cover from ATL09 at the 25 Hz rate(275m) indicating likely presence of snow and ice within each segment. 0=ice free water; 1=snow free land; 2=snow; 3=ice."; String coordinates "delta_time latitude longitude"; String flag_meanings "ice_free_water snow_free_land snow ice Undetermined"; Byte flag_values 0, 1, 2, 3, 255; } /gt1l/land_segments/beam_azimuth { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/beam_azimuth"; Float32 _FillValue 3.402823466e+38; String long_name "beam azimuth"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; String description "Azimuth(in radians) of the unit pointing vector for the reference photon in the local ENU frame in radians. The angle is measured from north and positive towards East."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/solar_azimuth { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/solar_azimuth"; String long_name "solar azimuth"; String units "degrees_east"; String source "ATL03 ATBD"; String contentType "referenceInformation"; String description "The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/psf_flag { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/psf_flag"; String long_name "point spread function flag"; String units "1"; String source "Land/Veg ATBD Refine Ground Estimates"; Byte valid_min 0; Byte valid_max 255; String contentType "referenceInformation"; String description "Flag is set to 1 if the point spread function (computed as sigma_atlas_land) has exceeded the threshold (1 m)"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt1l/land_segments/longitude { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/longitude"; String long_name "longitude"; String standard_name "longitude"; String units "degrees"; String source "Land ATBD segment parameters for Land Products"; Float32 valid_min -180.; Float32 valid_max 180.; String contentType "modelResult"; String description "Longitude of the center-most signal photon within each segment."; String coordinates "delta_time latitude"; } /gt1l/land_segments/latitude { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/latitude"; String long_name "latitude"; String standard_name "latitude"; String units "degrees"; String source "Land ATBD segment parameters for Land Products"; Float32 valid_min -90.; Float32 valid_max 90.; String contentType "modelResult"; String description "Latitude of the center-most signal photon within each segment."; String coordinates "delta_time longitude"; } /gt1l/land_segments/segment_id_end { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/segment_id_end"; String long_name "end geolocation segment bin"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Geolocation segment number of the last photon in the land segment."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/longitude_20m { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/longitude_20m"; Float32 _FillValue 3.402823466e+38; String long_name "longitude of 20m segments"; String units "degree"; String source "ATBD Geosegment longitude"; Float32 valid_min -180.; Float32 valid_max 180.; String contentType "modelResult"; String description "Center longitude of 20m geosegments within each 100m land segment."; String coordinates "latitude longitude delta_time"; } /gt1l/land_segments/surf_type { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/surf_type"; String long_name "surface type"; String units "1"; String source "ATL03 ATBD"; Int16 valid_min 0; Int16 valid_max 1; String contentType "referenceInformation"; String description "Flags describing which surface types this interval is associated with. 0=not type, 1=is type. Order of array is land, ocean, sea ice, land ice, inland water."; String coordinates "delta_time latitude longitude"; String flag_meanings "not_type is_type"; Int16 flag_values 0, 1; } /gt1l/land_segments/brightness_flag { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/brightness_flag"; String long_name "brightness flag"; String units "1"; String source "Land ATBD Brightness_flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "Flag indicating that the ground surface is bright (e.g. snow-covered or other bright surfaces)"; String coordinates "delta_time latitude longitude"; String flag_meanings "not_bright_surface bright_surface Undetermined"; Byte flag_values 0, 1, 255; } /gt1l/land_segments/segment_landcover { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/segment_landcover"; String long_name "segment landcover"; String units "1"; String source "ATL08 ATBD segment_landcover"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "UN-FAO Land Cover Surface type classification as reference from Copernicus Land Cover(ANC18) at the 100m resolution."; String coordinates "delta_time latitude longitude"; String flag_meanings "No_data Closed_forest_evergreen_needle_leaf Closed_forest_deciduous_needle_leaf Closed_forest_evergreen_broad_leaf Closed_forest_deciduous_broad_leaf Closed_forest_mixed Closed_forest_unknown Open_forest_evergreen_needle_leaf Open_forest_deciduous_needle_leaf Open_forest_evergreen_broad_leaf Open_forest_deciduous_broad_leaf Open_forest_mixed Open_forest_unknown Shrubs Herbaceous Herbaceous_wetleand Moss_and_lichen Bare_sparse_vegetation Cultivated_and_managed_vegetation_agriculture Urban_built_up Snow_and_ice Permanent_water_bodies Open_sea Undetermined"; Byte flag_values 0, 111, 113, 112, 114, 115, 116, 121, 123, 122, 124, 125, 126, 20, 30, 90, 100, 60, 40, 50, 70, 80, 200, 255; } /gt1l/land_segments/ph_removal_flag { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/ph_removal_flag"; String long_name "ph removal flag"; String units "1"; String source "ATBD Final photon classification QA"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Flag indicating more than ph_removal_percent_limit (default 50.0) removed from land segment due to failing QA tests"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt1l/land_segments/asr { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/asr"; Float32 _FillValue 3.402823466e+38; String long_name "apparent surface reflectance"; String units "1"; String source "ATL09"; String contentType "auxiliaryInformation"; String description "Apparent surface reflectance"; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/sigma_atlas_land { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/sigma_atlas_land"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas land"; String units "1"; String source "Land ATBD Refine Ground Estimates"; String contentType "referenceInformation"; String description "Total vertical geolocation error due to ranging and local surface slope. The parameter is computed for ATL08 as described in equation 1.2 ATL08 ATBD."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/segment_id_beg { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/segment_id_beg"; String long_name "begin geolocation segment bin"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Geolocation segment number of the first photon in the land segment."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/sigma_along { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/sigma_along"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas x"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Total along-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_along. Sigma_atlas_x is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/dem_h { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/dem_h"; Float32 _FillValue 3.402823466e+38; String long_name "dem height"; String units "meters"; String source "Arctic, Antarctic, Global, MSS DEM"; String contentType "referenceInformation"; String description "Best available DEM (in priority of Arctic/Antarctic/Global/MSS) value at the geolocation point. Height is in meters above the WGS84 Ellipsoid."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/beam_coelev { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/beam_coelev"; Float32 _FillValue 3.402823466e+38; String long_name "beam co-elevation"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt1l/land_segments/sat_flag { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/sat_flag"; String long_name "saturation flag"; String units "1"; String source "ATL03, Land ATBD Saturation Flag"; Int16 valid_min -1; Int16 valid_max 127; String contentType "auxiliaryInformation"; String description "Flag derived from full_sat_fract on the ATL03 data product, averaged over 5 geosegments in 100m land segment"; String coordinates "delta_time latitude longitude"; String flag_meanings "no_saturation_detected saturation_detected not_enough_valid_data Undetermined"; Int16 flag_values 0, 1, -1, 127; } /gt1l/land_segments/sigma_topo { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/sigma_topo"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas topo"; String units "1"; String source "Land ATBD Refine Ground Estimates"; String contentType "referenceInformation"; String description "Total uncertainty that include sigma_h plus geolocation uncertainty due to local slope (equation 1.3). The local slope is multiplied by the geolocation uncertainty factor. This will be used to determine the total vertical geolocation error due to ranging and local slope."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/night_flag { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/night_flag"; String long_name "night flag"; String units "1"; String source "Land ATBD Night_Flag"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Flag indicating the data were acquired in night conditions: 0=day, 1=night. Flag is derived from solar elevation at the geolocated segment. IF solar elevation is above threshold it is day, if not then it is night. Threshold is set in atlas_l3a_const_mod."; String coordinates "delta_time latitude longitude"; String flag_meanings "day night Undetermined"; Byte flag_values 0, 1, 255; } /gt1l/land_segments/delta_time_beg { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/delta_time_beg"; String long_name "delta time begin"; String units "seconds since 2018-01-01"; String source "Derived (gps_seconds-gps_sec_offset)"; String contentType "referenceInformation"; String description "Time of the first photon contained within the data segment, in seconds since the ATLAS SDP GPS Epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/sigma_h { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/sigma_h"; Float32 _FillValue 3.402823466e+38; String long_name "height uncertainty"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m) provided at the geolocation segment rate on ATL03. Sigma_h is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/last_seg_extend { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/last_seg_extend"; String long_name "last segment extended"; String standard_name "last_seg_extend"; String units "kilometers"; String source "Land ATBD Preparing ATL03 data for input"; String contentType "auxiliaryInformation"; String description "The distance (km) that the last ATL08 processing segment in a file is either extended or overlapped with the previous ATL08 processing segment."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/column_od_asr { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/column_od_asr"; Float32 _FillValue 3.402823466e+38; String long_name "Column optical depth from ASR"; String units "1"; String source "ATL09"; String contentType "auxiliaryInformation"; String description "Optical depth of atmosphere column based on apparent surface reflectance and the assumed actual surface reflectance."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/atlas_pa { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/atlas_pa"; Float32 _FillValue 3.402823466e+38; String long_name "atlas pointing angle"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; String description "Off nadir pointing angle (in radians) of the satellite to increase spatial sampling in the non-polar regions. ATLAS_PA =radians(90degs-beam_coelev)."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/ph_ndx_beg { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/ph_ndx_beg"; String long_name "photon index begin"; String units "1"; String source "Derived"; String contentType "auxiliaryInformation"; String description "Index (1-based) within the photon-rate data (/land_segments/photons) of the first photon within this each land segment."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/solar_elevation { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/solar_elevation"; String long_name "solar elevation"; String units "degrees"; String source "ATL03 ATBD"; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt1l/land_segments/delta_time { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/delta_time"; String CLASS "DIMENSION_SCALE"; String long_name "mean_pass_time"; String standard_name "time"; String units "seconds since 2018-01-01"; String source "Land ATBD segment parameters for Land Products"; String contentType "referenceInformation"; String description "Mean time for the segment in number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "latitude longitude"; String NAME "delta_time"; } /gt1l/land_segments/cloud_fold_flag { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/cloud_fold_flag"; String long_name "cloud folding flag"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 127; String contentType "modelResult"; String description "Flag that indicates this profile likely contains cloud signal folded down from above 15 km to the last 2-3 km of the profile. See ATL09 ATBD Table 3.9 for detailed flag value meanings."; String coordinates "delta_time latitude longitude"; String flag_meanings "no_folding goes5_indicates profile_indicates both_indicate outside_limits"; Int16 flag_values 0, 1, 2, 3, 127; } /gt1l/land_segments/n_seg_ph { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/n_seg_ph"; String long_name "number of photons"; String units "1"; String source "Derived"; String contentType "auxiliaryInformation"; String description "Number of photons within each land segment."; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/terrain_flg { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/terrain_flg"; String long_name "terrain flag"; String units "1"; String source "Land ATBD Segment_terrain flag"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Terrain flag quality check to indicate a deviation above a threshold from the reference DEM height reported on the product."; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt1l/land_segments/urban_flag { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/urban_flag"; String long_name "segment urban flag"; String units "1"; String source "Land ATBD Urban_flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "The urban flag indicates that a segment is likely located over an urban area as determined by coincident pixels in the Global Urban Footprint (GUF) 0.4 arcsecond product."; String coordinates "delta_time latitude longitude"; String flag_meanings "not_urban urban Undetermined"; Byte flag_values 0, 1, 255; } /gt1l/land_segments/permafrost_alt { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/permafrost_alt"; Float32 _FillValue 3.402823466e+38; String long_name "permafrost active layer thickness"; String standard_name "permafrost_alt"; String units "meters"; String source "ESA CCI, ANC47"; Float32 valid_min 0.; Float32 valid_max 100.; String contentType "referenceInformation"; String description "Permafrost active layer thickness (m) from ESA CCI 2019 northern hemisphere permafrost dataset"; String coordinates "delta_time latitude longitude"; } /gt1l/land_segments/dem_removal_flag { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/dem_removal_flag"; String long_name "dem removal flag"; String units "1"; String source "ATBD Segment reference DEM removal flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "Flag indicating more than dem_removal_percent_limit (default 20.0) removed from land segment due to failing DEM-QA tests"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt1l/land_segments/h_dif_ref { String HDF5_OBJ_FULLPATH "/gt1l/land_segments/h_dif_ref"; Float32 _FillValue 3.402823466e+38; String long_name "h dif from reference"; String units "meters"; String source "Land ATBD segment parameters for Land Products"; String contentType "modelResult"; String description "Difference between h_te_median and ref_DEM"; String coordinates "delta_time latitude longitude"; } /gt1l/signal_photons/ { String HDF5_OBJ_FULLPATH "/gt1l/signal_photons/"; String description "Contains parameters related to individual photons."; String data_rate "Data are stored at the signal-photon classification rate."; } /gt1l/signal_photons/classed_pc_flag { String HDF5_OBJ_FULLPATH "/gt1l/signal_photons/classed_pc_flag"; String long_name "photon land atbd classification"; String units "1"; String source "Land ATBD Subgroup: Photons"; String contentType "modelResult"; String description "Land Vegetation ATBD classification flag for each photon as either noise, ground, canopy, and top of canopy. 0 = noise, 1 = ground, 2 = canopy, or 3 = top of canopy."; String coordinates "delta_time"; String flag_meanings "noise ground canopy top_of_canopy"; Int16 flag_values 0, 1, 2, 3; } /gt1l/signal_photons/classed_pc_indx { String HDF5_OBJ_FULLPATH "/gt1l/signal_photons/classed_pc_indx"; String units "1"; String long_name "indicies of classed photons"; String source "Retained from prior a_alt_science_ph packet"; String contentType "referenceInformation"; String description "Index (1-based) of the ATL08 classified signal photon from the start of the ATL03 geolocation segment specified on the ATL08 product at the photon rate in the corresponding parameter, ph_segment_id. This index traces back to specific photon within a 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group."; String coordinates "delta_time"; } /gt1l/signal_photons/ph_h { String HDF5_OBJ_FULLPATH "/gt1l/signal_photons/ph_h"; Float32 _FillValue 3.402823466e+38; String long_name "relative photon height"; String standard_name "height"; String units "meters"; String source "Land ATBD Subgroup: Photons"; String contentType "physicalMeasurement"; String description "Height of photons above interpolated land surface"; String coordinates "delta_time"; } /gt1l/signal_photons/d_flag { String HDF5_OBJ_FULLPATH "/gt1l/signal_photons/d_flag"; String long_name "dragann flag"; String units "1"; String source "Land ATBD Subgroup: Photons"; String contentType "qualityInformation"; String description "Flag indicating the labeling of DRAGANN noise filtering for a given photon."; String coordinates "delta_time"; String flag_meanings "noise signal"; Int16 flag_values 0, 1; } /gt1l/signal_photons/delta_time { String HDF5_OBJ_FULLPATH "/gt1l/signal_photons/delta_time"; String CLASS "DIMENSION_SCALE"; String NAME "delta_time"; String long_name "delta time"; String standard_name "time"; String units "seconds since 2018-01-01"; String source "ATL03"; String contentType "auxiliaryInformation"; 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."; } /gt1l/signal_photons/ph_segment_id { String HDF5_OBJ_FULLPATH "/gt1l/signal_photons/ph_segment_id"; String long_name "segment id of photon"; String units "1"; String source "Retained from prior a_alt_science_ph packet"; String contentType "referenceInformation"; String description "Segment ID of photons tracing back to specific 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the photon on ATL03 is the segment_id, orbit, and classed_pc_indx. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group."; String coordinates "delta_time"; } /ds_surf_type { String HDF5_OBJ_FULLPATH "/ds_surf_type"; String long_name "Surface Type Dimension Scale"; String units "1"; String source "Dim Scale"; Int32 valid_min 1; Int32 valid_max 5; String contentType "auxiliaryInformation"; String description "Dimension scale indexing the surface type array. Index=1 corresponds to Land; index = 2 corresponds to Ocean; Index = 3 corresponds to SeaIce; Index=4 corresponds to LandIce; Index=5 corresponds to InlandWater"; String flag_meanings "land ocean seaice landice inland_water"; Int32 flag_values 1, 2, 3, 4, 5; String CLASS "DIMENSION_SCALE"; String NAME "/ds_surf_type"; } /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 long_name "Granule Failure Reason"; String units "1"; String source "Operations"; Int32 valid_min 0; Int32 valid_max 5; 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; } /quality_assessment/qa_granule_pass_fail { String HDF5_OBJ_FULLPATH "/quality_assessment/qa_granule_pass_fail"; String long_name "Granule Pass Flag"; String units "1"; String source "Operations"; Int32 valid_min 0; Int32 valid_max 1; 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; } /gt3l/ { String HDF5_OBJ_FULLPATH "/gt3l/"; String atlas_pce "pce3"; String atlas_beam_type "strong"; String groundtrack_id "gt3l"; String atmosphere_profile "profile_3"; String atlas_spot_number "5"; String sc_orientation "Backward"; } /gt3l/land_segments/ { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/"; String description "Contains data categorized as land at 100 meter intervals."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt3l/land_segments/segment_watermask { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/segment_watermask"; String long_name "segment watermask"; String units "1"; String source "ATL08 ATBD segment_watermask"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Water mask(i.e. flag) indicating inland water as referenced from the Global Raster Water Mask(ANC33) at 250 m spatial resolution."; String coordinates "delta_time latitude longitude"; String flag_meanings "no_water water Undetermined"; Byte flag_values 0, 1, 255; } /gt3l/land_segments/delta_time_end { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/delta_time_end"; String long_name "delta time end"; String units "seconds since 2018-01-01"; String source "Derived (gps_seconds-gps_sec_offset)"; String contentType "referenceInformation"; String description "Time of the last photon contained within the data segment, in seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/latitude_20m { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/latitude_20m"; Float32 _FillValue 3.402823466e+38; String long_name "latitude of 20m segments"; String units "degree"; String source "ATBD Geosegment latitude"; Float32 valid_min -90.; Float32 valid_max 90.; String contentType "modelResult"; String description "Center latitude of 20m geosegments within each 100m land segment."; String coordinates "latitude longitude delta_time"; } /gt3l/land_segments/rgt { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/rgt"; String long_name "reference ground track"; String units "1"; String source "Operations"; Int16 valid_min 1; Int16 valid_max 1387; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt3l/land_segments/dem_flag { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/dem_flag"; String long_name "dem source flag"; String units "1"; String source "Atmosphere ATBD"; Int16 valid_min 0; Int16 valid_max 127; String contentType "referenceInformation"; String description "Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=Global, 3=MSS, 4=Antarctic."; String coordinates "delta_time latitude longitude"; String flag_meanings "none arctic global mss antarctic Undetermined"; Int16 flag_values 0, 1, 2, 3, 4, 127; } /gt3l/land_segments/msw_flag { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/msw_flag"; String long_name "multiple scattering warning flag"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 127; String contentType "qualityInformation"; String description "Multiple Scattering Warning flag. If no layers were detected, then msw_flag = 0. If blowing snow is detected and its estimated optical depth is greater than or equal to 0.5, then msw_flag = 5. If the blowing snow optical depth is less than 0.5, then msw_flag = 4. If no blowing snow is detected but there are cloud or aerosol layers detected, the msw_flag assumes values of 1 to 3 based on the height of the bottom of the lowest layer: < 1 km, msw_flag = 3; 1-3 km, msw_flag = 2; > 3km, msw_flag = 1. A value of 127 indicates that the signal to noise of the data was too low to reliably ascertain the presence of cloud or blowing snow. We expect values of 127 to occur only during daylight."; String coordinates "delta_time latitude longitude"; 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 127, 0, 1, 2, 3, 4, 5; } /gt3l/land_segments/permafrost_prob { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/permafrost_prob"; Int16 _FillValue 127; String long_name "permafrost probaility"; String standard_name "permafrost_prob"; String units "percent"; String source "ESA CCI, ANC47"; Int16 valid_min 0; Int16 valid_max 100; String contentType "referenceInformation"; String description "Permafrost probability (0 - 100) derived via percent of permafrost within pixel cell area in ESA CCI 2019 northern hemisphere permafrost dataset"; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/cloud_flag_atm { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/cloud_flag_atm"; Int16 _FillValue 127; String long_name "cloud flag atm"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 10; String contentType "qualityInformation"; String description "Cloud confidence flag from ATL09 that indicates the number of cloud or aerosol layers identified in each 25Hz atmospheric profile. If the flag is greater than 0, aerosols or clouds could be present. Valid range is 0 - 10."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/snr { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/snr"; Float32 _FillValue 3.402823466e+38; String long_name "signal to noise ratio"; String units "1"; String source "ATBD Noise filtering via DRAGANN"; String contentType "modelResult"; String description "The signal to noise ratio of geolocated photons as determined by the ratio of the superset of ATL03 signal and DRAGANN found signal photons used for processing the ATL08 segments to the background photons (i.e. noise) within the same ATL08 segments."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/canopy/ { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/"; String description "Contains height parameters based on the land algorithm."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt3l/land_segments/canopy/h_canopy { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/h_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "height canopy"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "98% height of all the individual canopy relative heights for the segment above the estimated terrain surface. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/canopy_rh_conf { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/canopy_rh_conf"; String units "1"; String long_name "canopy relative height confidence"; String source "Land/Veg ATBD Vegetation Parameters"; Int16 valid_min 0; Int16 valid_max 2; String contentType "modelResult"; String description "Canopy relative height confidence flag based on percentage of ground and canopy photons within a segment: 0 (<5% canopy), 1 (>5% canopy, <5% ground), 2 (>5% canopy, >5% ground)."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "<5%_canopy >=5%_canopy_<5%_ground >=5%_canopy_>=5%_ground"; Int16 flag_values 0, 1, 2; } /gt3l/land_segments/canopy/h_median_canopy_abs { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/h_median_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute segment median canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The median of individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/h_min_canopy { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/h_min_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "minimum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The minimum of relative individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/h_mean_canopy_abs { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/h_mean_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute mean canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Mean of the individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/h_median_canopy { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/h_median_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "median canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The median of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. This parameter should be equivalent to RH50 reported in the literature."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/h_canopy_abs { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/h_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute segment canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The 98% height of all the absolute individual canopy heights referenced above the WGS84 ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/toc_roughness { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/toc_roughness"; Float32 _FillValue 3.402823466e+38; String long_name "top of canopy roughness"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Standard deviation of the relative heights of all photons classified as top of canopy within the segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/h_min_canopy_abs { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/h_min_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute minimum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The minimum of absolute individual canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/h_dif_canopy { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/h_dif_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "canopy diff to median height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Difference between h_canopy and h_median_canopy"; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/h_canopy_quad { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/h_canopy_quad"; Float32 _FillValue 3.402823466e+38; String long_name "canopy quadratic mean"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The quadratic mean height of individual classified relative canopy photon heights above the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/h_canopy_20m { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/h_canopy_20m"; String units "m"; Float32 _FillValue 3.402823466e+38; String long_name "canopy height 20m"; String source "ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Canopy height for each 20m geosegment with each 100m land segment."; String coordinates "../latitude ../longitude ../delta_time"; } /gt3l/land_segments/canopy/n_ca_photons { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/n_ca_photons"; String long_name "number canopy photons"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The number of photons classified as canopy within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/photon_rate_can { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/photon_rate_can"; Float32 _FillValue 3.402823466e+38; String long_name "Canopy photon rate"; String units "s^-1"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Calculated photon rate of canopy photons within each 100m segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/centroid_height { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/centroid_height"; Float32 _FillValue 3.402823466e+38; String long_name "centroid height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Optical centroid of all photons classified as either canopy or ground points within the segment. The heights used in this calculation are absolute heights above the reference ellipsoid. This parameter is equivalent to the centroid height produced ICESat GLA14."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/canopy_h_metrics_abs { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/canopy_h_metrics_abs"; Float32 _FillValue 3.402823466e+38; String long_name "canopy absolute height metrics"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Height metrics based on the cumulative distribution of absolute canopy heights above the WGS84 Ellipsoid. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/can_noise { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/can_noise"; Float32 _FillValue 3.402823466e+38; String long_name "canopy noise rate"; String units "count/meter"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Number of noise photons calculated that fall within the canopy height for each 100 m segment based on ATL03 background rate parameters."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/h_mean_canopy { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/h_mean_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "mean canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Mean of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/subset_can_flag { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/subset_can_flag"; Int16 _FillValue 127; String long_name "subset canopy flag"; String units "1"; String source "Land ATBD Vegetation Parameters"; Int16 valid_min -1; Int16 valid_max 1; String contentType "modelResult"; String description "Quality flag indicating the canopy photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "no_photon_data_within_geosegment no_canopy_photons_within_geosegment canopy_photons_present_within_geosegment"; Int16 flag_values -1, 0, 1; } /gt3l/land_segments/canopy/canopy_h_metrics { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/canopy_h_metrics"; Float32 _FillValue 3.402823466e+38; String long_name "canopy height metrics"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Height metrics based on the cumulative distribution of relative canopy heights above the interpolated ground surface. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/n_toc_photons { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/n_toc_photons"; String long_name "number top of canopy photons"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The number of photons classified as top of canopy within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/h_max_canopy_abs { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/h_max_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute maximum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Maximum of individual absolute canopy heights within segment referenced above the WGS84 ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/h_canopy_uncertainty { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/h_canopy_uncertainty"; Float32 _FillValue 3.402823466e+38; String long_name "segment canopy height uncertainty"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "qualityInformation"; String description "Uncertainty of the relative canopy heights for the segment. Incorporates all systematic uncertainties as well as uncertainty from errors of identified photons. See section 1 and equations 1.4 and 1.5 of the ATL08 ATBD."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/photon_rate_can_nr { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/photon_rate_can_nr"; Float32 _FillValue 3.402823466e+38; String long_name "noise reduced number of canopy photons"; String units "s^-1"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Noise removed photon canopy rate within each 100 m segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/can_quality_score { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/can_quality_score"; String units "1"; String source "Land ATBD Vegetation Parameters"; Int16 valid_min 0; Int16 valid_max 100; String contentType "modelResult"; String description "Canopy quality score based on coincident conditions, from ATL08 ATBD section titled \"Canopy Quality Score\"."; String coordinates "../delta_time ../latitude ../longitude"; Int16 _FillValue 127; String long_name "canopy quality score"; } /gt3l/land_segments/canopy/canopy_openness { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/canopy_openness"; Float32 _FillValue 3.402823466e+38; String long_name "canopy openness"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Standard Deviation of all photons classified as canopy photons within the segment to provide inference of canopy openness."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/h_max_canopy { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/h_max_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "maximum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Relative maximum of individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. Should be equivalent to RH100 metric reported in the literature."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/canopy/segment_cover { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/canopy/segment_cover"; Int16 _FillValue 32767; String long_name "canopy cover percentage"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Average percentage value of the valid (value <= 100) Copernicus fractional cover product for each 100 m segment. This data is temporally static, and is the summation of forest and shrub land cover fractions. Source data from: https://land.copernicus.eu/en/products/global-dynamic-land-cover/copernicus-global-land-service-land-cover-100m-collection-3-epoch-2019-globe ."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/sigma_across { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/sigma_across"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas y"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Total cross-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_across. Sigma_atlas_y is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/terrain/ { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/"; String description "Contains terrain parameters at a 100m aggregation."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt3l/land_segments/terrain/h_te_uncertainty { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/h_te_uncertainty"; Float32 _FillValue 3.402823466e+38; String long_name "uncertainty of h_te_mean"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Uncertainty of the mean terrain height for the segment. This uncertainty incorporates all systematic uncertainties(e.g. timing orbits, geolocation,etc.) as well as uncertainty from errors of identified photons. This parameter is described in section 1, equation 1.4 in ATL08 ATBD."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/terrain/h_te_mean { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/h_te_mean"; Float32 _FillValue 3.402823466e+38; String long_name "mean terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The mean of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/terrain/h_te_min { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/h_te_min"; Float32 _FillValue 3.402823466e+38; String long_name "minimum terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The minimum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/terrain/photon_rate_te { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/photon_rate_te"; Float32 _FillValue 3.402823466e+38; String long_name "Terrain photon rate"; String units "s^-1"; String source "Land ATBD Land Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Calculated photon rate of terrain photons within each 100m segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/terrain/h_te_interp { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/h_te_interp"; Float32 _FillValue 3.402823466e+38; String long_name "interpolated terrain surface height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Interpolated terrain surface height above the WGS84 Ellipsoid at the midpoint of the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/terrain/h_te_max { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/h_te_max"; Float32 _FillValue 3.402823466e+38; String long_name "maximum terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The maximum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/terrain/h_te_rh25 { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/h_te_rh25"; String units "meters"; Float32 _FillValue 3.402823466e+38; String long_name "Terrain height 25% percentile"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The terrain elevation from the 25% height. The classified ground photons are sorted into a cumulative distribution and the height associated with the 25% height for that segment is reported."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/terrain/h_te_skew { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/h_te_skew"; Float32 _FillValue 3.402823466e+38; String long_name "skew of terrain heights"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The skewness of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/terrain/h_te_best_fit_20m { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/h_te_best_fit_20m"; Float32 _FillValue 3.402823466e+38; String long_name "best fit 20m"; String units "m"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Best fit terrain height to center of each 20m geosegment within each 100m land segment."; String coordinates "../latitude ../longitude ../delta_time"; } /gt3l/land_segments/terrain/h_te_median { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/h_te_median"; Float32 _FillValue 3.402823466e+38; String long_name "median terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The median of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/terrain/h_te_best_fit { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/h_te_best_fit"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain height best fit"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The best fit terrain elevation at the the mid-point location of each 100m segment. The mid-segment terrain elevation is determined by selecting the best of three fits- linear, 3rd order and 4th order polynomials - to the terrain photons and interpolating the elevation at the mid-point location of the 100 m segment. For the linear fit, a slope correction and weighting is applied to each ground photon based on the distance to the slope height at the center of the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/terrain/h_te_std { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/h_te_std"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain roughness"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The standard deviation of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/terrain/terrain_slope { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/terrain_slope"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain slope"; String units "1"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The along-track slope of terrain, within each segment;computed by a linear fit of terrain classified photons. Slope is in units of delta height over delta along track distance."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/terrain/subset_te_flag { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/subset_te_flag"; Int16 _FillValue 127; String long_name "subset terrain flag"; String units "1"; String source "Land ATBD Land Parameters"; Int16 valid_min -1; Int16 valid_max 1; String contentType "modelResult"; String description "Quality flag indicating the terrain photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "no_photon_data_within_geosegment no_terrain_photons_within_geosegment terrain_photons_present_within_geosegment"; Int16 flag_values -1, 0, 1; } /gt3l/land_segments/terrain/n_te_photons { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/n_te_photons"; String long_name "number of ground photons"; String units "1"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The number of the photons classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/terrain/h_te_mode { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/h_te_mode"; Float32 _FillValue 3.402823466e+38; String long_name "mode of terrain heights"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The mode of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/terrain/te_quality_score { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain/te_quality_score"; Int16 _FillValue 127; String long_name "terrain quality score"; String units "1"; String source "Land ATBD Land Parameters"; Int16 valid_min 0; Int16 valid_max 100; String contentType "modelResult"; String description "Quality score based on coincident conditions, from ATL08 ATBD section titled \"Terrain Quality Score\"."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3l/land_segments/layer_flag { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/layer_flag"; String long_name "consolidated cloud flag"; String units "1"; String source "ATL09"; String contentType "modelResult"; 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 coordinates "delta_time latitude longitude"; String flag_meanings "likely_clear likely_cloudy"; Int16 flag_values 0, 1; } /gt3l/land_segments/segment_snowcover { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/segment_snowcover"; String long_name "segment snowcover"; String units "1"; String source "ATL08 ATBD segment_snowcover"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Daily snow/ice cover from ATL09 at the 25 Hz rate(275m) indicating likely presence of snow and ice within each segment. 0=ice free water; 1=snow free land; 2=snow; 3=ice."; String coordinates "delta_time latitude longitude"; String flag_meanings "ice_free_water snow_free_land snow ice Undetermined"; Byte flag_values 0, 1, 2, 3, 255; } /gt3l/land_segments/beam_azimuth { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/beam_azimuth"; Float32 _FillValue 3.402823466e+38; String long_name "beam azimuth"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; String description "Azimuth(in radians) of the unit pointing vector for the reference photon in the local ENU frame in radians. The angle is measured from north and positive towards East."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/solar_azimuth { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/solar_azimuth"; String long_name "solar azimuth"; String units "degrees_east"; String source "ATL03 ATBD"; String contentType "referenceInformation"; String description "The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/psf_flag { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/psf_flag"; String long_name "point spread function flag"; String units "1"; String source "Land/Veg ATBD Refine Ground Estimates"; Byte valid_min 0; Byte valid_max 255; String contentType "referenceInformation"; String description "Flag is set to 1 if the point spread function (computed as sigma_atlas_land) has exceeded the threshold (1 m)"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt3l/land_segments/longitude { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/longitude"; String long_name "longitude"; String standard_name "longitude"; String units "degrees"; String source "Land ATBD segment parameters for Land Products"; Float32 valid_min -180.; Float32 valid_max 180.; String contentType "modelResult"; String description "Longitude of the center-most signal photon within each segment."; String coordinates "delta_time latitude"; } /gt3l/land_segments/latitude { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/latitude"; String long_name "latitude"; String standard_name "latitude"; String units "degrees"; String source "Land ATBD segment parameters for Land Products"; Float32 valid_min -90.; Float32 valid_max 90.; String contentType "modelResult"; String description "Latitude of the center-most signal photon within each segment."; String coordinates "delta_time longitude"; } /gt3l/land_segments/segment_id_end { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/segment_id_end"; String long_name "end geolocation segment bin"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Geolocation segment number of the last photon in the land segment."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/longitude_20m { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/longitude_20m"; Float32 _FillValue 3.402823466e+38; String long_name "longitude of 20m segments"; String units "degree"; String source "ATBD Geosegment longitude"; Float32 valid_min -180.; Float32 valid_max 180.; String contentType "modelResult"; String description "Center longitude of 20m geosegments within each 100m land segment."; String coordinates "latitude longitude delta_time"; } /gt3l/land_segments/surf_type { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/surf_type"; String long_name "surface type"; String units "1"; String source "ATL03 ATBD"; Int16 valid_min 0; Int16 valid_max 1; String contentType "referenceInformation"; String description "Flags describing which surface types this interval is associated with. 0=not type, 1=is type. Order of array is land, ocean, sea ice, land ice, inland water."; String coordinates "delta_time latitude longitude"; String flag_meanings "not_type is_type"; Int16 flag_values 0, 1; } /gt3l/land_segments/brightness_flag { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/brightness_flag"; String long_name "brightness flag"; String units "1"; String source "Land ATBD Brightness_flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "Flag indicating that the ground surface is bright (e.g. snow-covered or other bright surfaces)"; String coordinates "delta_time latitude longitude"; String flag_meanings "not_bright_surface bright_surface Undetermined"; Byte flag_values 0, 1, 255; } /gt3l/land_segments/segment_landcover { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/segment_landcover"; String long_name "segment landcover"; String units "1"; String source "ATL08 ATBD segment_landcover"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "UN-FAO Land Cover Surface type classification as reference from Copernicus Land Cover(ANC18) at the 100m resolution."; String coordinates "delta_time latitude longitude"; String flag_meanings "No_data Closed_forest_evergreen_needle_leaf Closed_forest_deciduous_needle_leaf Closed_forest_evergreen_broad_leaf Closed_forest_deciduous_broad_leaf Closed_forest_mixed Closed_forest_unknown Open_forest_evergreen_needle_leaf Open_forest_deciduous_needle_leaf Open_forest_evergreen_broad_leaf Open_forest_deciduous_broad_leaf Open_forest_mixed Open_forest_unknown Shrubs Herbaceous Herbaceous_wetleand Moss_and_lichen Bare_sparse_vegetation Cultivated_and_managed_vegetation_agriculture Urban_built_up Snow_and_ice Permanent_water_bodies Open_sea Undetermined"; Byte flag_values 0, 111, 113, 112, 114, 115, 116, 121, 123, 122, 124, 125, 126, 20, 30, 90, 100, 60, 40, 50, 70, 80, 200, 255; } /gt3l/land_segments/ph_removal_flag { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/ph_removal_flag"; String long_name "ph removal flag"; String units "1"; String source "ATBD Final photon classification QA"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Flag indicating more than ph_removal_percent_limit (default 50.0) removed from land segment due to failing QA tests"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt3l/land_segments/asr { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/asr"; Float32 _FillValue 3.402823466e+38; String long_name "apparent surface reflectance"; String units "1"; String source "ATL09"; String contentType "auxiliaryInformation"; String description "Apparent surface reflectance"; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/sigma_atlas_land { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/sigma_atlas_land"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas land"; String units "1"; String source "Land ATBD Refine Ground Estimates"; String contentType "referenceInformation"; String description "Total vertical geolocation error due to ranging and local surface slope. The parameter is computed for ATL08 as described in equation 1.2 ATL08 ATBD."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/segment_id_beg { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/segment_id_beg"; String long_name "begin geolocation segment bin"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Geolocation segment number of the first photon in the land segment."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/sigma_along { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/sigma_along"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas x"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Total along-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_along. Sigma_atlas_x is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/dem_h { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/dem_h"; Float32 _FillValue 3.402823466e+38; String long_name "dem height"; String units "meters"; String source "Arctic, Antarctic, Global, MSS DEM"; String contentType "referenceInformation"; String description "Best available DEM (in priority of Arctic/Antarctic/Global/MSS) value at the geolocation point. Height is in meters above the WGS84 Ellipsoid."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/beam_coelev { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/beam_coelev"; Float32 _FillValue 3.402823466e+38; String long_name "beam co-elevation"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt3l/land_segments/sat_flag { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/sat_flag"; String long_name "saturation flag"; String units "1"; String source "ATL03, Land ATBD Saturation Flag"; Int16 valid_min -1; Int16 valid_max 127; String contentType "auxiliaryInformation"; String description "Flag derived from full_sat_fract on the ATL03 data product, averaged over 5 geosegments in 100m land segment"; String coordinates "delta_time latitude longitude"; String flag_meanings "no_saturation_detected saturation_detected not_enough_valid_data Undetermined"; Int16 flag_values 0, 1, -1, 127; } /gt3l/land_segments/sigma_topo { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/sigma_topo"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas topo"; String units "1"; String source "Land ATBD Refine Ground Estimates"; String contentType "referenceInformation"; String description "Total uncertainty that include sigma_h plus geolocation uncertainty due to local slope (equation 1.3). The local slope is multiplied by the geolocation uncertainty factor. This will be used to determine the total vertical geolocation error due to ranging and local slope."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/night_flag { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/night_flag"; String long_name "night flag"; String units "1"; String source "Land ATBD Night_Flag"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Flag indicating the data were acquired in night conditions: 0=day, 1=night. Flag is derived from solar elevation at the geolocated segment. IF solar elevation is above threshold it is day, if not then it is night. Threshold is set in atlas_l3a_const_mod."; String coordinates "delta_time latitude longitude"; String flag_meanings "day night Undetermined"; Byte flag_values 0, 1, 255; } /gt3l/land_segments/delta_time_beg { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/delta_time_beg"; String long_name "delta time begin"; String units "seconds since 2018-01-01"; String source "Derived (gps_seconds-gps_sec_offset)"; String contentType "referenceInformation"; String description "Time of the first photon contained within the data segment, in seconds since the ATLAS SDP GPS Epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/sigma_h { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/sigma_h"; Float32 _FillValue 3.402823466e+38; String long_name "height uncertainty"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m) provided at the geolocation segment rate on ATL03. Sigma_h is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/last_seg_extend { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/last_seg_extend"; String long_name "last segment extended"; String standard_name "last_seg_extend"; String units "kilometers"; String source "Land ATBD Preparing ATL03 data for input"; String contentType "auxiliaryInformation"; String description "The distance (km) that the last ATL08 processing segment in a file is either extended or overlapped with the previous ATL08 processing segment."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/column_od_asr { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/column_od_asr"; Float32 _FillValue 3.402823466e+38; String long_name "Column optical depth from ASR"; String units "1"; String source "ATL09"; String contentType "auxiliaryInformation"; String description "Optical depth of atmosphere column based on apparent surface reflectance and the assumed actual surface reflectance."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/atlas_pa { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/atlas_pa"; Float32 _FillValue 3.402823466e+38; String long_name "atlas pointing angle"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; String description "Off nadir pointing angle (in radians) of the satellite to increase spatial sampling in the non-polar regions. ATLAS_PA =radians(90degs-beam_coelev)."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/ph_ndx_beg { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/ph_ndx_beg"; String long_name "photon index begin"; String units "1"; String source "Derived"; String contentType "auxiliaryInformation"; String description "Index (1-based) within the photon-rate data (/land_segments/photons) of the first photon within this each land segment."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/solar_elevation { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/solar_elevation"; String long_name "solar elevation"; String units "degrees"; String source "ATL03 ATBD"; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt3l/land_segments/delta_time { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/delta_time"; String CLASS "DIMENSION_SCALE"; String long_name "mean_pass_time"; String standard_name "time"; String units "seconds since 2018-01-01"; String source "Land ATBD segment parameters for Land Products"; String contentType "referenceInformation"; String description "Mean time for the segment in number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "latitude longitude"; String NAME "delta_time"; } /gt3l/land_segments/cloud_fold_flag { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/cloud_fold_flag"; String long_name "cloud folding flag"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 127; String contentType "modelResult"; String description "Flag that indicates this profile likely contains cloud signal folded down from above 15 km to the last 2-3 km of the profile. See ATL09 ATBD Table 3.9 for detailed flag value meanings."; String coordinates "delta_time latitude longitude"; String flag_meanings "no_folding goes5_indicates profile_indicates both_indicate outside_limits"; Int16 flag_values 0, 1, 2, 3, 127; } /gt3l/land_segments/n_seg_ph { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/n_seg_ph"; String long_name "number of photons"; String units "1"; String source "Derived"; String contentType "auxiliaryInformation"; String description "Number of photons within each land segment."; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/terrain_flg { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/terrain_flg"; String long_name "terrain flag"; String units "1"; String source "Land ATBD Segment_terrain flag"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Terrain flag quality check to indicate a deviation above a threshold from the reference DEM height reported on the product."; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt3l/land_segments/urban_flag { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/urban_flag"; String long_name "segment urban flag"; String units "1"; String source "Land ATBD Urban_flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "The urban flag indicates that a segment is likely located over an urban area as determined by coincident pixels in the Global Urban Footprint (GUF) 0.4 arcsecond product."; String coordinates "delta_time latitude longitude"; String flag_meanings "not_urban urban Undetermined"; Byte flag_values 0, 1, 255; } /gt3l/land_segments/permafrost_alt { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/permafrost_alt"; Float32 _FillValue 3.402823466e+38; String long_name "permafrost active layer thickness"; String standard_name "permafrost_alt"; String units "meters"; String source "ESA CCI, ANC47"; Float32 valid_min 0.; Float32 valid_max 100.; String contentType "referenceInformation"; String description "Permafrost active layer thickness (m) from ESA CCI 2019 northern hemisphere permafrost dataset"; String coordinates "delta_time latitude longitude"; } /gt3l/land_segments/dem_removal_flag { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/dem_removal_flag"; String long_name "dem removal flag"; String units "1"; String source "ATBD Segment reference DEM removal flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "Flag indicating more than dem_removal_percent_limit (default 20.0) removed from land segment due to failing DEM-QA tests"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt3l/land_segments/h_dif_ref { String HDF5_OBJ_FULLPATH "/gt3l/land_segments/h_dif_ref"; Float32 _FillValue 3.402823466e+38; String long_name "h dif from reference"; String units "meters"; String source "Land ATBD segment parameters for Land Products"; String contentType "modelResult"; String description "Difference between h_te_median and ref_DEM"; String coordinates "delta_time latitude longitude"; } /gt3l/signal_photons/ { String HDF5_OBJ_FULLPATH "/gt3l/signal_photons/"; String description "Contains parameters related to individual photons."; String data_rate "Data are stored at the signal-photon classification rate."; } /gt3l/signal_photons/classed_pc_flag { String HDF5_OBJ_FULLPATH "/gt3l/signal_photons/classed_pc_flag"; String long_name "photon land atbd classification"; String units "1"; String source "Land ATBD Subgroup: Photons"; String contentType "modelResult"; String description "Land Vegetation ATBD classification flag for each photon as either noise, ground, canopy, and top of canopy. 0 = noise, 1 = ground, 2 = canopy, or 3 = top of canopy."; String coordinates "delta_time"; String flag_meanings "noise ground canopy top_of_canopy"; Int16 flag_values 0, 1, 2, 3; } /gt3l/signal_photons/classed_pc_indx { String HDF5_OBJ_FULLPATH "/gt3l/signal_photons/classed_pc_indx"; String units "1"; String long_name "indicies of classed photons"; String source "Retained from prior a_alt_science_ph packet"; String contentType "referenceInformation"; String description "Index (1-based) of the ATL08 classified signal photon from the start of the ATL03 geolocation segment specified on the ATL08 product at the photon rate in the corresponding parameter, ph_segment_id. This index traces back to specific photon within a 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group."; String coordinates "delta_time"; } /gt3l/signal_photons/ph_h { String HDF5_OBJ_FULLPATH "/gt3l/signal_photons/ph_h"; Float32 _FillValue 3.402823466e+38; String long_name "relative photon height"; String standard_name "height"; String units "meters"; String source "Land ATBD Subgroup: Photons"; String contentType "physicalMeasurement"; String description "Height of photons above interpolated land surface"; String coordinates "delta_time"; } /gt3l/signal_photons/d_flag { String HDF5_OBJ_FULLPATH "/gt3l/signal_photons/d_flag"; String long_name "dragann flag"; String units "1"; String source "Land ATBD Subgroup: Photons"; String contentType "qualityInformation"; String description "Flag indicating the labeling of DRAGANN noise filtering for a given photon."; String coordinates "delta_time"; String flag_meanings "noise signal"; Int16 flag_values 0, 1; } /gt3l/signal_photons/delta_time { String HDF5_OBJ_FULLPATH "/gt3l/signal_photons/delta_time"; String CLASS "DIMENSION_SCALE"; String NAME "delta_time"; String long_name "delta time"; String standard_name "time"; String units "seconds since 2018-01-01"; String source "ATL03"; String contentType "auxiliaryInformation"; 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."; } /gt3l/signal_photons/ph_segment_id { String HDF5_OBJ_FULLPATH "/gt3l/signal_photons/ph_segment_id"; String long_name "segment id of photon"; String units "1"; String source "Retained from prior a_alt_science_ph packet"; String contentType "referenceInformation"; String description "Segment ID of photons tracing back to specific 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the photon on ATL03 is the segment_id, orbit, and classed_pc_indx. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group."; String coordinates "delta_time"; } /ds_geosegments { String HDF5_OBJ_FULLPATH "/ds_geosegments"; String CLASS "DIMENSION_SCALE"; String NAME "ds_geosegments"; String long_name "Geosegments"; String units "1"; String source "Dim Scale"; Int16 valid_min 1; Int16 valid_max 5; String contentType "auxiliaryInformation"; String description "Dimension scale for geosegments within land segments."; String flag_meanings "geosegments1 geosegments2 geosegments3 geosegments4 geosegments5"; Int16 flag_values 1, 2, 3, 4, 5; } /gt2l/ { String HDF5_OBJ_FULLPATH "/gt2l/"; String atlas_pce "pce2"; String atlas_beam_type "strong"; String groundtrack_id "gt2l"; String atmosphere_profile "profile_2"; String atlas_spot_number "3"; String sc_orientation "Backward"; } /gt2l/land_segments/ { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/"; String description "Contains data categorized as land at 100 meter intervals."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt2l/land_segments/segment_watermask { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/segment_watermask"; String long_name "segment watermask"; String units "1"; String source "ATL08 ATBD segment_watermask"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Water mask(i.e. flag) indicating inland water as referenced from the Global Raster Water Mask(ANC33) at 250 m spatial resolution."; String coordinates "delta_time latitude longitude"; String flag_meanings "no_water water Undetermined"; Byte flag_values 0, 1, 255; } /gt2l/land_segments/delta_time_end { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/delta_time_end"; String long_name "delta time end"; String units "seconds since 2018-01-01"; String source "Derived (gps_seconds-gps_sec_offset)"; String contentType "referenceInformation"; String description "Time of the last photon contained within the data segment, in seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/latitude_20m { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/latitude_20m"; Float32 _FillValue 3.402823466e+38; String long_name "latitude of 20m segments"; String units "degree"; String source "ATBD Geosegment latitude"; Float32 valid_min -90.; Float32 valid_max 90.; String contentType "modelResult"; String description "Center latitude of 20m geosegments within each 100m land segment."; String coordinates "latitude longitude delta_time"; } /gt2l/land_segments/rgt { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/rgt"; String long_name "reference ground track"; String units "1"; String source "Operations"; Int16 valid_min 1; Int16 valid_max 1387; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt2l/land_segments/dem_flag { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/dem_flag"; String long_name "dem source flag"; String units "1"; String source "Atmosphere ATBD"; Int16 valid_min 0; Int16 valid_max 127; String contentType "referenceInformation"; String description "Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=Global, 3=MSS, 4=Antarctic."; String coordinates "delta_time latitude longitude"; String flag_meanings "none arctic global mss antarctic Undetermined"; Int16 flag_values 0, 1, 2, 3, 4, 127; } /gt2l/land_segments/msw_flag { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/msw_flag"; String long_name "multiple scattering warning flag"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 127; String contentType "qualityInformation"; String description "Multiple Scattering Warning flag. If no layers were detected, then msw_flag = 0. If blowing snow is detected and its estimated optical depth is greater than or equal to 0.5, then msw_flag = 5. If the blowing snow optical depth is less than 0.5, then msw_flag = 4. If no blowing snow is detected but there are cloud or aerosol layers detected, the msw_flag assumes values of 1 to 3 based on the height of the bottom of the lowest layer: < 1 km, msw_flag = 3; 1-3 km, msw_flag = 2; > 3km, msw_flag = 1. A value of 127 indicates that the signal to noise of the data was too low to reliably ascertain the presence of cloud or blowing snow. We expect values of 127 to occur only during daylight."; String coordinates "delta_time latitude longitude"; 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 127, 0, 1, 2, 3, 4, 5; } /gt2l/land_segments/permafrost_prob { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/permafrost_prob"; Int16 _FillValue 127; String long_name "permafrost probaility"; String standard_name "permafrost_prob"; String units "percent"; String source "ESA CCI, ANC47"; Int16 valid_min 0; Int16 valid_max 100; String contentType "referenceInformation"; String description "Permafrost probability (0 - 100) derived via percent of permafrost within pixel cell area in ESA CCI 2019 northern hemisphere permafrost dataset"; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/cloud_flag_atm { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/cloud_flag_atm"; Int16 _FillValue 127; String long_name "cloud flag atm"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 10; String contentType "qualityInformation"; String description "Cloud confidence flag from ATL09 that indicates the number of cloud or aerosol layers identified in each 25Hz atmospheric profile. If the flag is greater than 0, aerosols or clouds could be present. Valid range is 0 - 10."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/snr { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/snr"; Float32 _FillValue 3.402823466e+38; String long_name "signal to noise ratio"; String units "1"; String source "ATBD Noise filtering via DRAGANN"; String contentType "modelResult"; String description "The signal to noise ratio of geolocated photons as determined by the ratio of the superset of ATL03 signal and DRAGANN found signal photons used for processing the ATL08 segments to the background photons (i.e. noise) within the same ATL08 segments."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/canopy/ { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/"; String description "Contains height parameters based on the land algorithm."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt2l/land_segments/canopy/h_canopy { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/h_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "height canopy"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "98% height of all the individual canopy relative heights for the segment above the estimated terrain surface. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/canopy_rh_conf { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/canopy_rh_conf"; String units "1"; String long_name "canopy relative height confidence"; String source "Land/Veg ATBD Vegetation Parameters"; Int16 valid_min 0; Int16 valid_max 2; String contentType "modelResult"; String description "Canopy relative height confidence flag based on percentage of ground and canopy photons within a segment: 0 (<5% canopy), 1 (>5% canopy, <5% ground), 2 (>5% canopy, >5% ground)."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "<5%_canopy >=5%_canopy_<5%_ground >=5%_canopy_>=5%_ground"; Int16 flag_values 0, 1, 2; } /gt2l/land_segments/canopy/h_median_canopy_abs { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/h_median_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute segment median canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The median of individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/h_min_canopy { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/h_min_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "minimum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The minimum of relative individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/h_mean_canopy_abs { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/h_mean_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute mean canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Mean of the individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/h_median_canopy { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/h_median_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "median canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The median of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. This parameter should be equivalent to RH50 reported in the literature."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/h_canopy_abs { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/h_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute segment canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The 98% height of all the absolute individual canopy heights referenced above the WGS84 ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/toc_roughness { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/toc_roughness"; Float32 _FillValue 3.402823466e+38; String long_name "top of canopy roughness"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Standard deviation of the relative heights of all photons classified as top of canopy within the segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/h_min_canopy_abs { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/h_min_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute minimum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The minimum of absolute individual canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/h_dif_canopy { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/h_dif_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "canopy diff to median height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Difference between h_canopy and h_median_canopy"; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/h_canopy_quad { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/h_canopy_quad"; Float32 _FillValue 3.402823466e+38; String long_name "canopy quadratic mean"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The quadratic mean height of individual classified relative canopy photon heights above the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/h_canopy_20m { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/h_canopy_20m"; String units "m"; Float32 _FillValue 3.402823466e+38; String long_name "canopy height 20m"; String source "ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Canopy height for each 20m geosegment with each 100m land segment."; String coordinates "../latitude ../longitude ../delta_time"; } /gt2l/land_segments/canopy/n_ca_photons { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/n_ca_photons"; String long_name "number canopy photons"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The number of photons classified as canopy within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/photon_rate_can { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/photon_rate_can"; Float32 _FillValue 3.402823466e+38; String long_name "Canopy photon rate"; String units "s^-1"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Calculated photon rate of canopy photons within each 100m segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/centroid_height { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/centroid_height"; Float32 _FillValue 3.402823466e+38; String long_name "centroid height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Optical centroid of all photons classified as either canopy or ground points within the segment. The heights used in this calculation are absolute heights above the reference ellipsoid. This parameter is equivalent to the centroid height produced ICESat GLA14."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/canopy_h_metrics_abs { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/canopy_h_metrics_abs"; Float32 _FillValue 3.402823466e+38; String long_name "canopy absolute height metrics"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Height metrics based on the cumulative distribution of absolute canopy heights above the WGS84 Ellipsoid. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/can_noise { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/can_noise"; Float32 _FillValue 3.402823466e+38; String long_name "canopy noise rate"; String units "count/meter"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Number of noise photons calculated that fall within the canopy height for each 100 m segment based on ATL03 background rate parameters."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/h_mean_canopy { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/h_mean_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "mean canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Mean of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/subset_can_flag { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/subset_can_flag"; Int16 _FillValue 127; String long_name "subset canopy flag"; String units "1"; String source "Land ATBD Vegetation Parameters"; Int16 valid_min -1; Int16 valid_max 1; String contentType "modelResult"; String description "Quality flag indicating the canopy photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "no_photon_data_within_geosegment no_canopy_photons_within_geosegment canopy_photons_present_within_geosegment"; Int16 flag_values -1, 0, 1; } /gt2l/land_segments/canopy/canopy_h_metrics { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/canopy_h_metrics"; Float32 _FillValue 3.402823466e+38; String long_name "canopy height metrics"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Height metrics based on the cumulative distribution of relative canopy heights above the interpolated ground surface. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/n_toc_photons { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/n_toc_photons"; String long_name "number top of canopy photons"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The number of photons classified as top of canopy within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/h_max_canopy_abs { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/h_max_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute maximum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Maximum of individual absolute canopy heights within segment referenced above the WGS84 ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/h_canopy_uncertainty { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/h_canopy_uncertainty"; Float32 _FillValue 3.402823466e+38; String long_name "segment canopy height uncertainty"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "qualityInformation"; String description "Uncertainty of the relative canopy heights for the segment. Incorporates all systematic uncertainties as well as uncertainty from errors of identified photons. See section 1 and equations 1.4 and 1.5 of the ATL08 ATBD."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/photon_rate_can_nr { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/photon_rate_can_nr"; Float32 _FillValue 3.402823466e+38; String long_name "noise reduced number of canopy photons"; String units "s^-1"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Noise removed photon canopy rate within each 100 m segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/can_quality_score { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/can_quality_score"; String units "1"; String source "Land ATBD Vegetation Parameters"; Int16 valid_min 0; Int16 valid_max 100; String contentType "modelResult"; String description "Canopy quality score based on coincident conditions, from ATL08 ATBD section titled \"Canopy Quality Score\"."; String coordinates "../delta_time ../latitude ../longitude"; Int16 _FillValue 127; String long_name "canopy quality score"; } /gt2l/land_segments/canopy/canopy_openness { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/canopy_openness"; Float32 _FillValue 3.402823466e+38; String long_name "canopy openness"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Standard Deviation of all photons classified as canopy photons within the segment to provide inference of canopy openness."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/h_max_canopy { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/h_max_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "maximum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Relative maximum of individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. Should be equivalent to RH100 metric reported in the literature."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/canopy/segment_cover { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/canopy/segment_cover"; Int16 _FillValue 32767; String long_name "canopy cover percentage"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Average percentage value of the valid (value <= 100) Copernicus fractional cover product for each 100 m segment. This data is temporally static, and is the summation of forest and shrub land cover fractions. Source data from: https://land.copernicus.eu/en/products/global-dynamic-land-cover/copernicus-global-land-service-land-cover-100m-collection-3-epoch-2019-globe ."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/sigma_across { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/sigma_across"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas y"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Total cross-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_across. Sigma_atlas_y is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/terrain/ { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/"; String description "Contains terrain parameters at a 100m aggregation."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt2l/land_segments/terrain/h_te_uncertainty { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/h_te_uncertainty"; Float32 _FillValue 3.402823466e+38; String long_name "uncertainty of h_te_mean"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Uncertainty of the mean terrain height for the segment. This uncertainty incorporates all systematic uncertainties(e.g. timing orbits, geolocation,etc.) as well as uncertainty from errors of identified photons. This parameter is described in section 1, equation 1.4 in ATL08 ATBD."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/terrain/h_te_mean { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/h_te_mean"; Float32 _FillValue 3.402823466e+38; String long_name "mean terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The mean of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/terrain/h_te_min { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/h_te_min"; Float32 _FillValue 3.402823466e+38; String long_name "minimum terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The minimum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/terrain/photon_rate_te { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/photon_rate_te"; Float32 _FillValue 3.402823466e+38; String long_name "Terrain photon rate"; String units "s^-1"; String source "Land ATBD Land Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Calculated photon rate of terrain photons within each 100m segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/terrain/h_te_interp { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/h_te_interp"; Float32 _FillValue 3.402823466e+38; String long_name "interpolated terrain surface height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Interpolated terrain surface height above the WGS84 Ellipsoid at the midpoint of the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/terrain/h_te_max { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/h_te_max"; Float32 _FillValue 3.402823466e+38; String long_name "maximum terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The maximum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/terrain/h_te_rh25 { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/h_te_rh25"; String units "meters"; Float32 _FillValue 3.402823466e+38; String long_name "Terrain height 25% percentile"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The terrain elevation from the 25% height. The classified ground photons are sorted into a cumulative distribution and the height associated with the 25% height for that segment is reported."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/terrain/h_te_skew { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/h_te_skew"; Float32 _FillValue 3.402823466e+38; String long_name "skew of terrain heights"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The skewness of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/terrain/h_te_best_fit_20m { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/h_te_best_fit_20m"; Float32 _FillValue 3.402823466e+38; String long_name "best fit 20m"; String units "m"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Best fit terrain height to center of each 20m geosegment within each 100m land segment."; String coordinates "../latitude ../longitude ../delta_time"; } /gt2l/land_segments/terrain/h_te_median { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/h_te_median"; Float32 _FillValue 3.402823466e+38; String long_name "median terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The median of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/terrain/h_te_best_fit { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/h_te_best_fit"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain height best fit"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The best fit terrain elevation at the the mid-point location of each 100m segment. The mid-segment terrain elevation is determined by selecting the best of three fits- linear, 3rd order and 4th order polynomials - to the terrain photons and interpolating the elevation at the mid-point location of the 100 m segment. For the linear fit, a slope correction and weighting is applied to each ground photon based on the distance to the slope height at the center of the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/terrain/h_te_std { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/h_te_std"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain roughness"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The standard deviation of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/terrain/terrain_slope { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/terrain_slope"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain slope"; String units "1"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The along-track slope of terrain, within each segment;computed by a linear fit of terrain classified photons. Slope is in units of delta height over delta along track distance."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/terrain/subset_te_flag { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/subset_te_flag"; Int16 _FillValue 127; String long_name "subset terrain flag"; String units "1"; String source "Land ATBD Land Parameters"; Int16 valid_min -1; Int16 valid_max 1; String contentType "modelResult"; String description "Quality flag indicating the terrain photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "no_photon_data_within_geosegment no_terrain_photons_within_geosegment terrain_photons_present_within_geosegment"; Int16 flag_values -1, 0, 1; } /gt2l/land_segments/terrain/n_te_photons { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/n_te_photons"; String long_name "number of ground photons"; String units "1"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The number of the photons classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/terrain/h_te_mode { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/h_te_mode"; Float32 _FillValue 3.402823466e+38; String long_name "mode of terrain heights"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The mode of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/terrain/te_quality_score { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain/te_quality_score"; Int16 _FillValue 127; String long_name "terrain quality score"; String units "1"; String source "Land ATBD Land Parameters"; Int16 valid_min 0; Int16 valid_max 100; String contentType "modelResult"; String description "Quality score based on coincident conditions, from ATL08 ATBD section titled \"Terrain Quality Score\"."; String coordinates "../delta_time ../latitude ../longitude"; } /gt2l/land_segments/layer_flag { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/layer_flag"; String long_name "consolidated cloud flag"; String units "1"; String source "ATL09"; String contentType "modelResult"; 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 coordinates "delta_time latitude longitude"; String flag_meanings "likely_clear likely_cloudy"; Int16 flag_values 0, 1; } /gt2l/land_segments/segment_snowcover { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/segment_snowcover"; String long_name "segment snowcover"; String units "1"; String source "ATL08 ATBD segment_snowcover"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Daily snow/ice cover from ATL09 at the 25 Hz rate(275m) indicating likely presence of snow and ice within each segment. 0=ice free water; 1=snow free land; 2=snow; 3=ice."; String coordinates "delta_time latitude longitude"; String flag_meanings "ice_free_water snow_free_land snow ice Undetermined"; Byte flag_values 0, 1, 2, 3, 255; } /gt2l/land_segments/beam_azimuth { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/beam_azimuth"; Float32 _FillValue 3.402823466e+38; String long_name "beam azimuth"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; String description "Azimuth(in radians) of the unit pointing vector for the reference photon in the local ENU frame in radians. The angle is measured from north and positive towards East."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/solar_azimuth { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/solar_azimuth"; String long_name "solar azimuth"; String units "degrees_east"; String source "ATL03 ATBD"; String contentType "referenceInformation"; String description "The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/psf_flag { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/psf_flag"; String long_name "point spread function flag"; String units "1"; String source "Land/Veg ATBD Refine Ground Estimates"; Byte valid_min 0; Byte valid_max 255; String contentType "referenceInformation"; String description "Flag is set to 1 if the point spread function (computed as sigma_atlas_land) has exceeded the threshold (1 m)"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt2l/land_segments/longitude { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/longitude"; String long_name "longitude"; String standard_name "longitude"; String units "degrees"; String source "Land ATBD segment parameters for Land Products"; Float32 valid_min -180.; Float32 valid_max 180.; String contentType "modelResult"; String description "Longitude of the center-most signal photon within each segment."; String coordinates "delta_time latitude"; } /gt2l/land_segments/latitude { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/latitude"; String long_name "latitude"; String standard_name "latitude"; String units "degrees"; String source "Land ATBD segment parameters for Land Products"; Float32 valid_min -90.; Float32 valid_max 90.; String contentType "modelResult"; String description "Latitude of the center-most signal photon within each segment."; String coordinates "delta_time longitude"; } /gt2l/land_segments/segment_id_end { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/segment_id_end"; String long_name "end geolocation segment bin"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Geolocation segment number of the last photon in the land segment."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/longitude_20m { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/longitude_20m"; Float32 _FillValue 3.402823466e+38; String long_name "longitude of 20m segments"; String units "degree"; String source "ATBD Geosegment longitude"; Float32 valid_min -180.; Float32 valid_max 180.; String contentType "modelResult"; String description "Center longitude of 20m geosegments within each 100m land segment."; String coordinates "latitude longitude delta_time"; } /gt2l/land_segments/surf_type { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/surf_type"; String long_name "surface type"; String units "1"; String source "ATL03 ATBD"; Int16 valid_min 0; Int16 valid_max 1; String contentType "referenceInformation"; String description "Flags describing which surface types this interval is associated with. 0=not type, 1=is type. Order of array is land, ocean, sea ice, land ice, inland water."; String coordinates "delta_time latitude longitude"; String flag_meanings "not_type is_type"; Int16 flag_values 0, 1; } /gt2l/land_segments/brightness_flag { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/brightness_flag"; String long_name "brightness flag"; String units "1"; String source "Land ATBD Brightness_flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "Flag indicating that the ground surface is bright (e.g. snow-covered or other bright surfaces)"; String coordinates "delta_time latitude longitude"; String flag_meanings "not_bright_surface bright_surface Undetermined"; Byte flag_values 0, 1, 255; } /gt2l/land_segments/segment_landcover { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/segment_landcover"; String long_name "segment landcover"; String units "1"; String source "ATL08 ATBD segment_landcover"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "UN-FAO Land Cover Surface type classification as reference from Copernicus Land Cover(ANC18) at the 100m resolution."; String coordinates "delta_time latitude longitude"; String flag_meanings "No_data Closed_forest_evergreen_needle_leaf Closed_forest_deciduous_needle_leaf Closed_forest_evergreen_broad_leaf Closed_forest_deciduous_broad_leaf Closed_forest_mixed Closed_forest_unknown Open_forest_evergreen_needle_leaf Open_forest_deciduous_needle_leaf Open_forest_evergreen_broad_leaf Open_forest_deciduous_broad_leaf Open_forest_mixed Open_forest_unknown Shrubs Herbaceous Herbaceous_wetleand Moss_and_lichen Bare_sparse_vegetation Cultivated_and_managed_vegetation_agriculture Urban_built_up Snow_and_ice Permanent_water_bodies Open_sea Undetermined"; Byte flag_values 0, 111, 113, 112, 114, 115, 116, 121, 123, 122, 124, 125, 126, 20, 30, 90, 100, 60, 40, 50, 70, 80, 200, 255; } /gt2l/land_segments/ph_removal_flag { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/ph_removal_flag"; String long_name "ph removal flag"; String units "1"; String source "ATBD Final photon classification QA"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Flag indicating more than ph_removal_percent_limit (default 50.0) removed from land segment due to failing QA tests"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt2l/land_segments/asr { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/asr"; Float32 _FillValue 3.402823466e+38; String long_name "apparent surface reflectance"; String units "1"; String source "ATL09"; String contentType "auxiliaryInformation"; String description "Apparent surface reflectance"; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/sigma_atlas_land { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/sigma_atlas_land"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas land"; String units "1"; String source "Land ATBD Refine Ground Estimates"; String contentType "referenceInformation"; String description "Total vertical geolocation error due to ranging and local surface slope. The parameter is computed for ATL08 as described in equation 1.2 ATL08 ATBD."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/segment_id_beg { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/segment_id_beg"; String long_name "begin geolocation segment bin"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Geolocation segment number of the first photon in the land segment."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/sigma_along { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/sigma_along"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas x"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Total along-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_along. Sigma_atlas_x is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/dem_h { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/dem_h"; Float32 _FillValue 3.402823466e+38; String long_name "dem height"; String units "meters"; String source "Arctic, Antarctic, Global, MSS DEM"; String contentType "referenceInformation"; String description "Best available DEM (in priority of Arctic/Antarctic/Global/MSS) value at the geolocation point. Height is in meters above the WGS84 Ellipsoid."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/beam_coelev { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/beam_coelev"; Float32 _FillValue 3.402823466e+38; String long_name "beam co-elevation"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt2l/land_segments/sat_flag { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/sat_flag"; String long_name "saturation flag"; String units "1"; String source "ATL03, Land ATBD Saturation Flag"; Int16 valid_min -1; Int16 valid_max 127; String contentType "auxiliaryInformation"; String description "Flag derived from full_sat_fract on the ATL03 data product, averaged over 5 geosegments in 100m land segment"; String coordinates "delta_time latitude longitude"; String flag_meanings "no_saturation_detected saturation_detected not_enough_valid_data Undetermined"; Int16 flag_values 0, 1, -1, 127; } /gt2l/land_segments/sigma_topo { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/sigma_topo"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas topo"; String units "1"; String source "Land ATBD Refine Ground Estimates"; String contentType "referenceInformation"; String description "Total uncertainty that include sigma_h plus geolocation uncertainty due to local slope (equation 1.3). The local slope is multiplied by the geolocation uncertainty factor. This will be used to determine the total vertical geolocation error due to ranging and local slope."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/night_flag { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/night_flag"; String long_name "night flag"; String units "1"; String source "Land ATBD Night_Flag"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Flag indicating the data were acquired in night conditions: 0=day, 1=night. Flag is derived from solar elevation at the geolocated segment. IF solar elevation is above threshold it is day, if not then it is night. Threshold is set in atlas_l3a_const_mod."; String coordinates "delta_time latitude longitude"; String flag_meanings "day night Undetermined"; Byte flag_values 0, 1, 255; } /gt2l/land_segments/delta_time_beg { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/delta_time_beg"; String long_name "delta time begin"; String units "seconds since 2018-01-01"; String source "Derived (gps_seconds-gps_sec_offset)"; String contentType "referenceInformation"; String description "Time of the first photon contained within the data segment, in seconds since the ATLAS SDP GPS Epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/sigma_h { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/sigma_h"; Float32 _FillValue 3.402823466e+38; String long_name "height uncertainty"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m) provided at the geolocation segment rate on ATL03. Sigma_h is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/last_seg_extend { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/last_seg_extend"; String long_name "last segment extended"; String standard_name "last_seg_extend"; String units "kilometers"; String source "Land ATBD Preparing ATL03 data for input"; String contentType "auxiliaryInformation"; String description "The distance (km) that the last ATL08 processing segment in a file is either extended or overlapped with the previous ATL08 processing segment."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/column_od_asr { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/column_od_asr"; Float32 _FillValue 3.402823466e+38; String long_name "Column optical depth from ASR"; String units "1"; String source "ATL09"; String contentType "auxiliaryInformation"; String description "Optical depth of atmosphere column based on apparent surface reflectance and the assumed actual surface reflectance."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/atlas_pa { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/atlas_pa"; Float32 _FillValue 3.402823466e+38; String long_name "atlas pointing angle"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; String description "Off nadir pointing angle (in radians) of the satellite to increase spatial sampling in the non-polar regions. ATLAS_PA =radians(90degs-beam_coelev)."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/ph_ndx_beg { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/ph_ndx_beg"; String long_name "photon index begin"; String units "1"; String source "Derived"; String contentType "auxiliaryInformation"; String description "Index (1-based) within the photon-rate data (/land_segments/photons) of the first photon within this each land segment."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/solar_elevation { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/solar_elevation"; String long_name "solar elevation"; String units "degrees"; String source "ATL03 ATBD"; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt2l/land_segments/delta_time { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/delta_time"; String CLASS "DIMENSION_SCALE"; String long_name "mean_pass_time"; String standard_name "time"; String units "seconds since 2018-01-01"; String source "Land ATBD segment parameters for Land Products"; String contentType "referenceInformation"; String description "Mean time for the segment in number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "latitude longitude"; String NAME "delta_time"; } /gt2l/land_segments/cloud_fold_flag { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/cloud_fold_flag"; String long_name "cloud folding flag"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 127; String contentType "modelResult"; String description "Flag that indicates this profile likely contains cloud signal folded down from above 15 km to the last 2-3 km of the profile. See ATL09 ATBD Table 3.9 for detailed flag value meanings."; String coordinates "delta_time latitude longitude"; String flag_meanings "no_folding goes5_indicates profile_indicates both_indicate outside_limits"; Int16 flag_values 0, 1, 2, 3, 127; } /gt2l/land_segments/n_seg_ph { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/n_seg_ph"; String long_name "number of photons"; String units "1"; String source "Derived"; String contentType "auxiliaryInformation"; String description "Number of photons within each land segment."; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/terrain_flg { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/terrain_flg"; String long_name "terrain flag"; String units "1"; String source "Land ATBD Segment_terrain flag"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Terrain flag quality check to indicate a deviation above a threshold from the reference DEM height reported on the product."; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt2l/land_segments/urban_flag { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/urban_flag"; String long_name "segment urban flag"; String units "1"; String source "Land ATBD Urban_flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "The urban flag indicates that a segment is likely located over an urban area as determined by coincident pixels in the Global Urban Footprint (GUF) 0.4 arcsecond product."; String coordinates "delta_time latitude longitude"; String flag_meanings "not_urban urban Undetermined"; Byte flag_values 0, 1, 255; } /gt2l/land_segments/permafrost_alt { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/permafrost_alt"; Float32 _FillValue 3.402823466e+38; String long_name "permafrost active layer thickness"; String standard_name "permafrost_alt"; String units "meters"; String source "ESA CCI, ANC47"; Float32 valid_min 0.; Float32 valid_max 100.; String contentType "referenceInformation"; String description "Permafrost active layer thickness (m) from ESA CCI 2019 northern hemisphere permafrost dataset"; String coordinates "delta_time latitude longitude"; } /gt2l/land_segments/dem_removal_flag { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/dem_removal_flag"; String long_name "dem removal flag"; String units "1"; String source "ATBD Segment reference DEM removal flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "Flag indicating more than dem_removal_percent_limit (default 20.0) removed from land segment due to failing DEM-QA tests"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt2l/land_segments/h_dif_ref { String HDF5_OBJ_FULLPATH "/gt2l/land_segments/h_dif_ref"; Float32 _FillValue 3.402823466e+38; String long_name "h dif from reference"; String units "meters"; String source "Land ATBD segment parameters for Land Products"; String contentType "modelResult"; String description "Difference between h_te_median and ref_DEM"; String coordinates "delta_time latitude longitude"; } /gt2l/signal_photons/ { String HDF5_OBJ_FULLPATH "/gt2l/signal_photons/"; String description "Contains parameters related to individual photons."; String data_rate "Data are stored at the signal-photon classification rate."; } /gt2l/signal_photons/classed_pc_flag { String HDF5_OBJ_FULLPATH "/gt2l/signal_photons/classed_pc_flag"; String long_name "photon land atbd classification"; String units "1"; String source "Land ATBD Subgroup: Photons"; String contentType "modelResult"; String description "Land Vegetation ATBD classification flag for each photon as either noise, ground, canopy, and top of canopy. 0 = noise, 1 = ground, 2 = canopy, or 3 = top of canopy."; String coordinates "delta_time"; String flag_meanings "noise ground canopy top_of_canopy"; Int16 flag_values 0, 1, 2, 3; } /gt2l/signal_photons/classed_pc_indx { String HDF5_OBJ_FULLPATH "/gt2l/signal_photons/classed_pc_indx"; String units "1"; String long_name "indicies of classed photons"; String source "Retained from prior a_alt_science_ph packet"; String contentType "referenceInformation"; String description "Index (1-based) of the ATL08 classified signal photon from the start of the ATL03 geolocation segment specified on the ATL08 product at the photon rate in the corresponding parameter, ph_segment_id. This index traces back to specific photon within a 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group."; String coordinates "delta_time"; } /gt2l/signal_photons/ph_h { String HDF5_OBJ_FULLPATH "/gt2l/signal_photons/ph_h"; Float32 _FillValue 3.402823466e+38; String long_name "relative photon height"; String standard_name "height"; String units "meters"; String source "Land ATBD Subgroup: Photons"; String contentType "physicalMeasurement"; String description "Height of photons above interpolated land surface"; String coordinates "delta_time"; } /gt2l/signal_photons/d_flag { String HDF5_OBJ_FULLPATH "/gt2l/signal_photons/d_flag"; String long_name "dragann flag"; String units "1"; String source "Land ATBD Subgroup: Photons"; String contentType "qualityInformation"; String description "Flag indicating the labeling of DRAGANN noise filtering for a given photon."; String coordinates "delta_time"; String flag_meanings "noise signal"; Int16 flag_values 0, 1; } /gt2l/signal_photons/delta_time { String HDF5_OBJ_FULLPATH "/gt2l/signal_photons/delta_time"; String CLASS "DIMENSION_SCALE"; String NAME "delta_time"; String long_name "delta time"; String standard_name "time"; String units "seconds since 2018-01-01"; String source "ATL03"; String contentType "auxiliaryInformation"; 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."; } /gt2l/signal_photons/ph_segment_id { String HDF5_OBJ_FULLPATH "/gt2l/signal_photons/ph_segment_id"; String long_name "segment id of photon"; String units "1"; String source "Retained from prior a_alt_science_ph packet"; String contentType "referenceInformation"; String description "Segment ID of photons tracing back to specific 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the photon on ATL03 is the segment_id, orbit, and classed_pc_indx. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group."; String coordinates "delta_time"; } /ancillary_data/ { String HDF5_OBJ_FULLPATH "/ancillary_data/"; String data_rate "Data within this group pertain to the granule in its entirety."; 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 long_name "Release Number"; String units "1"; String source "Operations"; 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."; } /ancillary_data/end_geoseg { String HDF5_OBJ_FULLPATH "/ancillary_data/end_geoseg"; String long_name "Ending Geolocation Segment"; String units "1"; String source "Derived"; 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."; } /ancillary_data/version { String HDF5_OBJ_FULLPATH "/ancillary_data/version"; String long_name "Version"; String units "1"; String source "Operations"; 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."; } /ancillary_data/end_region { String HDF5_OBJ_FULLPATH "/ancillary_data/end_region"; String long_name "Ending Region"; String units "1"; String source "Derived"; 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."; } /ancillary_data/atlas_sdp_gps_epoch { String HDF5_OBJ_FULLPATH "/ancillary_data/atlas_sdp_gps_epoch"; String long_name "ATLAS Epoch Offset"; String units "seconds since 1980-01-06T00:00:00.000000Z"; String source "Operations"; 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."; } /ancillary_data/end_rgt { String HDF5_OBJ_FULLPATH "/ancillary_data/end_rgt"; String long_name "Ending Reference Groundtrack"; String units "1"; String source "Derived"; Int32 valid_min 1; Int32 valid_max 1387; 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."; } /ancillary_data/end_delta_time { String HDF5_OBJ_FULLPATH "/ancillary_data/end_delta_time"; String long_name "ATLAS End Time (Actual)"; String standard_name "time"; String units "seconds since 2018-01-01"; String source "Derived"; 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."; } /ancillary_data/end_orbit { String HDF5_OBJ_FULLPATH "/ancillary_data/end_orbit"; String long_name "Ending Orbit Number"; String units "1"; String source "Derived"; 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."; } /ancillary_data/start_cycle { String HDF5_OBJ_FULLPATH "/ancillary_data/start_cycle"; String long_name "Starting Cycle"; String units "1"; String source "Derived"; Int32 valid_min 0; Int32 valid_max 99; 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."; } /ancillary_data/data_end_utc { String HDF5_OBJ_FULLPATH "/ancillary_data/data_end_utc"; String long_name "End UTC Time of Granule (CCSDS-A, Actual)"; String units "1"; String source "Derived"; String contentType "auxiliaryInformation"; String description "UTC (in CCSDS-A format) of the last data point within the granule."; } /ancillary_data/control { String HDF5_OBJ_FULLPATH "/ancillary_data/control"; String long_name "Control File"; String units "1"; String source "Operations"; String contentType "auxiliaryInformation"; String description "PGE-specific control file used to generate this granule. To re-use, replace breaks (BR) with linefeeds."; } /ancillary_data/start_gpssow { String HDF5_OBJ_FULLPATH "/ancillary_data/start_gpssow"; String long_name "Start GPS SOW of Granule (Actual)"; String units "seconds"; String source "Derived"; String contentType "auxiliaryInformation"; String description "GPS seconds-of-week of the first data point in the granule."; } /ancillary_data/granule_end_utc { String HDF5_OBJ_FULLPATH "/ancillary_data/granule_end_utc"; String long_name "End UTC Time of Granule (CCSDS-A, Requested)"; String units "1"; String source "Derived"; String contentType "auxiliaryInformation"; String description "Requested end time (in UTC CCSDS-A) of this granule."; } /ancillary_data/end_cycle { String HDF5_OBJ_FULLPATH "/ancillary_data/end_cycle"; String long_name "Ending Cycle"; String units "1"; String source "Derived"; Int32 valid_min 0; Int32 valid_max 99; String contentType "auxiliaryInformation"; 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."; } /ancillary_data/granule_start_utc { String HDF5_OBJ_FULLPATH "/ancillary_data/granule_start_utc"; String long_name "Start UTC Time of Granule (CCSDS-A, Requested)"; String units "1"; String source "Derived"; String contentType "auxiliaryInformation"; String description "Requested start time (in UTC CCSDS-A) of this granule."; } /ancillary_data/land/ { String HDF5_OBJ_FULLPATH "/ancillary_data/land/"; String description "Constants used in the land_vegetation ATBD"; } /ancillary_data/land/stat20m_thresh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/stat20m_thresh"; String long_name "Threshold for geosegment statistics"; String units "1"; String source "ATBD canopy_height GeoSegment"; String contentType "auxiliaryInformation"; String description "Minimum number of photons to compute statistics upon. (Default =10)"; } /ancillary_data/land/ca_class { String HDF5_OBJ_FULLPATH "/ancillary_data/land/ca_class"; String long_name "Canopy class value"; String units "1"; String source "ATBD \"Classifying the Photons\""; String contentType "auxiliaryInformation"; String description "Canopy classification flag value. (Default = 2)"; } /ancillary_data/land/skill_solarang_can_penalty_2 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_solarang_can_penalty_2"; String long_name "Second canopy score demerit value for solar angle"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "Second canopy quality score demerit for solar elevation angle. (Default =10)"; } /ancillary_data/land/canopy_flag_switch { String HDF5_OBJ_FULLPATH "/ancillary_data/land/canopy_flag_switch"; String long_name "canopy_flag switch"; String units "1"; String source "ATBD Find top of canopy"; String contentType "auxiliaryInformation"; String description "Controls entrance to the canopy flag subroutine . (Default = 1)"; } /ancillary_data/land/skill_cldfold_can_penalty { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_cldfold_can_penalty"; String long_name "Canopy score demerit value for cloud fold flag"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "Canopy quality score demerit for cloud fold flag. (Default =10)"; } /ancillary_data/land/skill_demremov_can_penalty { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_demremov_can_penalty"; String long_name "Canopy score demerit value for DEM removal flag"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "Canopy quality score demerit for DEM removal flag. (Default =10)"; } /ancillary_data/land/skill_solarang_thrsh_te_1 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_solarang_thrsh_te_1"; String long_name "First threshold for solar angle terrain score demerit"; String units "degrees"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "First threshold of solar elevation angle for terrain quality score demerit. (Default =10.0)"; } /ancillary_data/land/skill_mswflag_can_penalty { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_mswflag_can_penalty"; String long_name "Canopy score demerit value for MSW flag"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "Canopy quality score demerit for MSW flag. (Default =10)"; } /ancillary_data/land/up_toc_bnd { String HDF5_OBJ_FULLPATH "/ancillary_data/land/up_toc_bnd"; String long_name "Upper bound restricting the search of a top of canopy surface."; String units "meters"; String source "ATBD Find the top of canopy"; String contentType "auxiliaryInformation"; String description "Upper bound restricting the search of a top of canopy surface. (Default=1.0)"; } /ancillary_data/land/skill_radmtry_thrsh_te_1 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_radmtry_thrsh_te_1"; String long_name "First threshold for radiometry terrain score demerit"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "First threshold of radiometry for terrain quality score demerit. (Default =0.2)"; } /ancillary_data/land/fnlgnd_filter_switch { String HDF5_OBJ_FULLPATH "/ancillary_data/land/fnlgnd_filter_switch"; String long_name "finalground filter switch"; String units "1"; String source "ATBD \"photon classification QA check\""; String contentType "auxiliaryInformation"; String description "Controls filtering based on FINALGROUND. (Default = 1)"; } /ancillary_data/land/skill_demremov_te_penalty { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_demremov_te_penalty"; String long_name "Terrain score demerit value for DEM removal flag"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "Terrain quality score demerit for DEM removal flag. (Default =10)"; } /ancillary_data/land/psf { String HDF5_OBJ_FULLPATH "/ancillary_data/land/psf"; String long_name "Point Spread Function"; String units "meters"; String source "ATBD Refine ground estimates"; String contentType "auxiliaryInformation"; String description "Parameter controlling identification of photons around an interpolated surface. (Default = 0.5)"; } /ancillary_data/land/dem_removal_percent_limit { String HDF5_OBJ_FULLPATH "/ancillary_data/land/dem_removal_percent_limit"; String long_name "dem_removal_flag set threshold"; String units "percent"; String source "ATBD \"segment_reference_DEM_removal_flag\""; String contentType "auxiliaryInformation"; String description "Percent of photons in land segment failing DEM test to set dem_removal_flag. (default = 20.0)"; } /ancillary_data/land/atl08_region { String HDF5_OBJ_FULLPATH "/ancillary_data/land/atl08_region"; String long_name "atl08 region"; String standard_name "atl08_region"; String units "1"; String source "Land ATBD reference summary table"; String contentType "modelResult"; String description "ATL08 region(s) encompassed by ATL03 granule being processed"; } /ancillary_data/land/can_noise_thresh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/can_noise_thresh"; String long_name "Threshold for reclassification of canopy as noise"; String source "ATBD \"Canopy Photon Filtering\""; String contentType "auxiliaryInformation"; String description "Threshold, as a number of canopy photons in the CAN_FILT_SEG, used for the reclassification of canopy signal photons. (Default = 75)"; String units "1"; } /ancillary_data/land/skill_radmtry_thrsh_te_2 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_radmtry_thrsh_te_2"; String long_name "Second threshold for radiometry terrain score demerit"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "Second threshold of radiometry for terrain quality score demerit. (Default =0.5)"; } /ancillary_data/land/relief_hbot { String HDF5_OBJ_FULLPATH "/ancillary_data/land/relief_hbot"; String long_name "lower relief percentile"; String units "meters"; String source "ATBD De-trend Data"; String contentType "auxiliaryInformation"; String description "The approximate relief of the L-km segment uses the percentile height values, relief_htop and relief_hbot. (Default=0.05)"; } /ancillary_data/land/dem_filter_switch { String HDF5_OBJ_FULLPATH "/ancillary_data/land/dem_filter_switch"; String long_name "dem_filter switch"; String units "1"; String source "ATBD De-trend Data"; String contentType "auxiliaryInformation"; String description "Controls filtering based on DEM. (Default = 1)"; } /ancillary_data/land/relief_htop { String HDF5_OBJ_FULLPATH "/ancillary_data/land/relief_htop"; String long_name "Upper relief percentile"; String units "meters"; String source "ATBD De-trend Data"; String contentType "auxiliaryInformation"; String description "The approximate relief of the L-km segment uses the percentile height values, relief_htop and relief_hbot. (Default=0.95)"; } /ancillary_data/land/dseg_buf { String HDF5_OBJ_FULLPATH "/ancillary_data/land/dseg_buf"; String long_name "DRAGANN segment buffer size"; String units "1"; String source "ATBD \"Noise filtering via DRAGANN\""; String contentType "auxiliaryInformation"; String description "DRAGANN segment buffer length in 20m geolocated segments along ground track. (Default=10)"; } /ancillary_data/land/night_thresh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/night_thresh"; String long_name "Threshold for night"; String units "1"; String source "ATBD Night_flag"; String contentType "auxiliaryInformation"; String description "Solar elevation threshold for determining night time conditions. (Default =0.0)"; } /ancillary_data/land/h_canopy_perc { String HDF5_OBJ_FULLPATH "/ancillary_data/land/h_canopy_perc"; String long_name "h_canopy percentile"; String units "1"; String source "ATBD segment parameters for Canopy Products"; String contentType "auxiliaryInformation"; String description "Percentile component of h_canopy parameter. (Default =0.95)"; } /ancillary_data/land/up_filt_bnd { String HDF5_OBJ_FULLPATH "/ancillary_data/land/up_filt_bnd"; String long_name "Proportionality coefficient for controlling the bounds of the filter window size as a function of number of signal photons."; String units "1"; String source "ATBD initial ground estimate"; String contentType "auxiliaryInformation"; String description "Lower bound of the filter window size function. (Default = 46)"; } /ancillary_data/land/lw_filt_bnd { String HDF5_OBJ_FULLPATH "/ancillary_data/land/lw_filt_bnd"; String long_name "Proportionality coefficient for controlling the bounds of the filter window size as a function of number of signal photons."; String units "1"; String source "ATBD initial ground estimate"; String contentType "auxiliaryInformation"; String description "Lower bound of the filter window size function. (Default = 5)"; } /ancillary_data/land/canopy20m_thresh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/canopy20m_thresh"; String long_name "Threshold for geosegment canopy"; String units "1"; String source "ATBD \"canopy_height GeoSegment\""; String contentType "auxiliaryInformation"; String description "Minimum number of photons to compute statistics upon. (Default =3)"; } /ancillary_data/land/skill_demremov_can_thrsh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_demremov_can_thrsh"; String long_name "Threshold for DEM removal flag canopy score demerit"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "Threshold of DEM removal flag for canopy quality score demerit. (Default =1)"; } /ancillary_data/land/skill_mswflag_te_penalty { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_mswflag_te_penalty"; String long_name "Terrain score demerit value for MSW flag"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "Terrain quality score demerit for MSW flag. (Default =10)"; } /ancillary_data/land/skill_od_thrsh_can_2 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_od_thrsh_can_2"; String long_name "Second threshold for optical depth canopy score demerit"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "Second threshold of optical depth for canopy quality score demerit. (Default =0.3)"; } /ancillary_data/land/ph_removal_percent_limit { String HDF5_OBJ_FULLPATH "/ancillary_data/land/ph_removal_percent_limit"; String long_name "ph_removal_flag set threshold"; String units "percent"; String source "ATBD Final photon classification QA"; String contentType "auxiliaryInformation"; String description "Percent of photons in land segment removed to set ph_removal_flag. (default = 50.0)"; } /ancillary_data/land/canopy_seg { String HDF5_OBJ_FULLPATH "/ancillary_data/land/canopy_seg"; String long_name "segment size in canopy filter"; String units "1"; String source "ATBD segment parameters for canopy products"; String contentType "auxiliaryInformation"; String description "Segment in number of signal photons for filtering sparse canopy cover. (Default = 500)"; } /ancillary_data/land/max_try { String HDF5_OBJ_FULLPATH "/ancillary_data/land/max_try"; String long_name "Maximum try count"; String units "1"; String source "ATBD \"dynamically determing a DRAGANN parameter\""; String contentType "auxiliaryInformation"; String description "Maximum number of tries to compute a P value in alternative DRAGANN"; } /ancillary_data/land/skill_radmtry_te_penalty_1 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_radmtry_te_penalty_1"; String long_name "First terrain score demerit value for radiometry"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "First terrain quality score demerit for radiometry. (Default =5)"; } /ancillary_data/land/bin_size_n { String HDF5_OBJ_FULLPATH "/ancillary_data/land/bin_size_n"; String long_name "neighbor histogram bin size"; String units "1"; String source "ATBD \"Noise filtering via DRAGANN\""; String contentType "auxiliaryInformation"; String description "Size of neighbor histogram bins in number of neighbors in DRAGANN. (Default = 1)"; } /ancillary_data/land/skill_od_can_penalty_2 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_od_can_penalty_2"; String long_name "Second canopy score demerit value for optical depth"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "Second canopy quality score demerit for optical depth. (Default =10)"; } /ancillary_data/land/lw_gnd_bnd { String HDF5_OBJ_FULLPATH "/ancillary_data/land/lw_gnd_bnd"; String long_name "Lower bound restricting the search of a ground surface in canopy cases."; String units "meters"; String source "ATBD initial ground estimate"; String contentType "auxiliaryInformation"; String description "Lower bound restricting the search of a ground surface in canopy cases. (Default = -4.0)"; } /ancillary_data/land/del_mu { String HDF5_OBJ_FULLPATH "/ancillary_data/land/del_mu"; String long_name "Step size for optimizing the mean parameter of Gaussian function."; String units "1"; String source "ATBD \"Noise filtering via DRAGANN\""; String contentType "auxiliaryInformation"; String description "Step size for optimizing the mean parameter of Gaussian function. (Default = 0.2)"; } /ancillary_data/land/skill_telemratio_can_thrsh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_telemratio_can_thrsh"; String long_name "Threshold for telemetry band ratio canopy score demerit"; String units "1"; String source "ATBD Terrain Canopy Score"; String contentType "auxiliaryInformation"; String description "Threshold of telemetry band ratio for canopy quality score demerit. (Default =0.4)"; } /ancillary_data/land/yapc_switch { String HDF5_OBJ_FULLPATH "/ancillary_data/land/yapc_switch"; String long_name "YAPC switch"; String units "1"; String source "ATBD De-trend Data"; String contentType "auxiliaryInformation"; String description "Controls inclusion of YAPC analysis for ground finding subroutines. (Default =1)"; } /ancillary_data/land/lw_toc_cut { String HDF5_OBJ_FULLPATH "/ancillary_data/land/lw_toc_cut"; String long_name "Lower cutoff for top of canopy"; String units "meters"; String source "ATBD Find the top of canopy"; String contentType "auxiliaryInformation"; String description "Lower cutoff for top of canopy surface. (Default = 2.0)"; } /ancillary_data/land/class_thresh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/class_thresh"; String long_name "Threshold flag value for classification of photons as signal via input from ATL03"; String units "1"; String source "ATBD section \"De-trend Data\""; String contentType "auxiliaryInformation"; String description "Threshold flag value for classification of photons as signal via input from ATL03. (Default =3)"; } /ancillary_data/land/skill_od_te_penalty_1 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_od_te_penalty_1"; String long_name "First terrain score demerit value for optical depth"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "First terrain quality score demerit for optical depth. (Default =5)"; } /ancillary_data/land/skill_od_can_penalty_1 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_od_can_penalty_1"; String long_name "First canopy score demerit value for optical depth"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "First canopy quality score demerit for optical depth. (Default =5)"; } /ancillary_data/land/lseg_buf { String HDF5_OBJ_FULLPATH "/ancillary_data/land/lseg_buf"; String long_name "Long segment buffer size"; String units "1"; String source "ATBD Preparing ATL03 data"; String contentType "auxiliaryInformation"; String description "Overlapping long segment buffer size in 20m geosegments along ground track. (Default=10)"; } /ancillary_data/land/lw_toc_bnd { String HDF5_OBJ_FULLPATH "/ancillary_data/land/lw_toc_bnd"; String long_name "Lower bound restricting the search of a top of canopy surface."; String units "meters"; String source "ATBD Find the top of canopy"; String contentType "auxiliaryInformation"; String description "Lower bound restricting the search of a top of canopy surface. (Default = -4.0)"; } /ancillary_data/land/up_toc_cut { String HDF5_OBJ_FULLPATH "/ancillary_data/land/up_toc_cut"; String long_name "upper cutoff of top of canopy surface."; String units "meters"; String source "ATBD Find the top of canopy"; String contentType "auxiliaryInformation"; String description "Upper cutoff for top of canopy surface. (Default = 150.0)"; } /ancillary_data/land/gnd_stat_thresh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/gnd_stat_thresh"; String long_name "Threshold for terrain statistics"; String units "1"; String source "ATBD segment parameters for Land Products"; String contentType "auxiliaryInformation"; String description "Minimum percentage of terrain photons to compute statistics upon. (Default =0.05)"; } /ancillary_data/land/iter_max { String HDF5_OBJ_FULLPATH "/ancillary_data/land/iter_max"; String long_name "Maximum number of iterations for optimizing the Gaussian parameters for fitting of histogram."; String units "1"; String source "ATBD \"Noise filtering via DRAGANN\""; String contentType "auxiliaryInformation"; String description "Maximum number of iterations for optimizing the Gaussian parameters for fitting of histogram. (Default = 10)"; } /ancillary_data/land/skill_cldfold_te_penalty { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_cldfold_te_penalty"; String long_name "Terrain score demerit value for cloud fold flag"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "Terrain quality score demerit for cloud fold flag. (Default =10)"; } /ancillary_data/land/skill_mswflag_te_thrsh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_mswflag_te_thrsh"; String long_name "Threshold for MSW flag terrain score demerit"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "Threshold of MSW flag for terrain quality score demerit. (Default =1)"; } /ancillary_data/land/skill_cldfold_can_thrsh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_cldfold_can_thrsh"; String long_name "Threshold for cloud fold flag canopy score demerit"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "Threshold of cloud fold flag for canopy quality score demerit. (Default =1)"; } /ancillary_data/land/gthresh_factor { String HDF5_OBJ_FULLPATH "/ancillary_data/land/gthresh_factor"; String long_name "threshold for Gaussian Elimination"; String units "1"; String source "ATBD \"Noise filtering via DRAGANN\""; String contentType "auxiliaryInformation"; String description "Controls threshold for Gaussian Elimination. (Default = 0.1)"; } /ancillary_data/land/skill_demremov_te_thrsh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_demremov_te_thrsh"; String long_name "Threshold for DEM removal flag terrain score demerit"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "Threshold of DEM removal flag for terrain quality score demerit. (Default =1)"; } /ancillary_data/land/skill_solarang_te_penalty_2 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_solarang_te_penalty_2"; String long_name "Second terrain score demerit value for solar angle"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "Second terrain quality score demerit for solar elevation angle. (Default =10)"; } /ancillary_data/land/skill_telemratio_te_thrsh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_telemratio_te_thrsh"; String long_name "Threshold for telemetry band ratio terrain score demerit"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "Threshold of telemetry band ratio for terrain quality score demerit. (Default =0.4)"; } /ancillary_data/land/bright_thresh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/bright_thresh"; String long_name "brightness flag average ph per shot"; String source "ATBD \"Brightness flag\""; String contentType "auxiliaryInformation"; String description "Threshold to set brightness_flag, average ground photons per shot. (Default = 3.0)"; String units "1"; } /ancillary_data/land/dseg { String HDF5_OBJ_FULLPATH "/ancillary_data/land/dseg"; String long_name "DRAGANN segment size"; String units "1"; String source "ATBD \"Noise filtering via DRAGANN\""; String contentType "auxiliaryInformation"; String description "DRAGANN segment length in 20m geolocated segments along ground track. (Default=170)"; } /ancillary_data/land/skill_solarang_can_penalty_1 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_solarang_can_penalty_1"; String long_name "First canopy score demerit value for solar angle"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "First canopy quality score demerit for solar elevation angle. (Default =5)"; } /ancillary_data/land/bin_size_h { String HDF5_OBJ_FULLPATH "/ancillary_data/land/bin_size_h"; String long_name "neighbor histogram bin size"; String units "1"; String source "ATBD \"Noise filtering via DRAGANN\""; String contentType "auxiliaryInformation"; String description "Histogram bin size for the alternative DRAGANN algorithm. (Default = 1.0)"; } /ancillary_data/land/up_gnd_bnd { String HDF5_OBJ_FULLPATH "/ancillary_data/land/up_gnd_bnd"; String long_name "Upper bound restricting the search of a ground surface in canopy cases."; String units "meters"; String source "ATBD initial ground estimate"; String contentType "auxiliaryInformation"; String description "Upper bound restricting the search of a ground surface in canopy cases. (Default = 1.0)"; } /ancillary_data/land/skill_solarang_thrsh_can_2 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_solarang_thrsh_can_2"; String long_name "Second threshold for solar angle canopy score demerit"; String units "degrees"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "Second threshold of solar elevation angle for canopy quality score demerit. (Default =20.0)"; } /ancillary_data/land/min_nphs { String HDF5_OBJ_FULLPATH "/ancillary_data/land/min_nphs"; String long_name "Minimum input photons"; String units "1"; String source "Operations"; String contentType "auxiliaryInformation"; String description "Minimum number of input photons from ATL03 to process. (default=1)"; } /ancillary_data/land/tc_thresh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/tc_thresh"; String long_name "Canopy Flag threshold"; String units "1"; String source "ATBD Segment parameters for canopy products"; String contentType "auxiliaryInformation"; String description "Percentage threshold for average L-km segment tree cover to be considered canopy. (Default = 5.0)"; } /ancillary_data/land/skill_solarang_te_penalty_1 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_solarang_te_penalty_1"; String long_name "First terrain score demerit value for solar angle"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "First terrain quality score demerit for solar elevation angle. (Default =5)"; } /ancillary_data/land/te_class { String HDF5_OBJ_FULLPATH "/ancillary_data/land/te_class"; String long_name "Terrain class value"; String units "1"; String source "ATBD \"Classifying the Photons\""; String contentType "auxiliaryInformation"; String description "Terrain classification flag value. (Default = 1)"; } /ancillary_data/land/toc_class { String HDF5_OBJ_FULLPATH "/ancillary_data/land/toc_class"; String long_name "Top of canopy class value"; String units "1"; String source "ATBD \"Classifying the Photons\""; String contentType "auxiliaryInformation"; String description "Top of canopy classification flag value. (Default = 3)"; } /ancillary_data/land/iter_gnd { String HDF5_OBJ_FULLPATH "/ancillary_data/land/iter_gnd"; String long_name "Iterations of smoothing of interpolated ground surface for ground estimate."; String units "1"; String source "ATBD Refine Ground Estimates"; String contentType "auxiliaryInformation"; String description "Iterations of smoothing of interpolated ground surface for refinement. (Default = 10)"; } /ancillary_data/land/max_atl03files { String HDF5_OBJ_FULLPATH "/ancillary_data/land/max_atl03files"; String long_name "Maximum number of input ATL03s"; String units "1"; String source "Operations"; String contentType "auxiliaryInformation"; String description "Maximum number of input ATL03 files. (Default = 200)"; } /ancillary_data/land/noise_class { String HDF5_OBJ_FULLPATH "/ancillary_data/land/noise_class"; String long_name "Noise class value"; String units "1"; String source "ATBD \"Classifying the Photons\""; String contentType "auxiliaryInformation"; String description "Noise classification flag value. (Default = 0)"; } /ancillary_data/land/skill_od_thrsh_can_1 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_od_thrsh_can_1"; String long_name "First threshold for optical depth canopy score demerit"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "First threshold of optical depth for canopy quality score demerit. (Default =0.2)"; String units "1"; } /ancillary_data/land/terrain20m_thresh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/terrain20m_thresh"; String long_name "Threshold for geosegment terrain"; String units "1"; String source "ATBD Terrain Best Fit GeoSegment"; String contentType "auxiliaryInformation"; String description "Minimum number of photons to compute statistics upon. (Default =3)"; } /ancillary_data/land/skill_cldfold_te_thrsh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_cldfold_te_thrsh"; String long_name "Threshold for cloud fold flag terrain score demerit"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "Threshold of cloud fold flag for terrain quality score demerit. (Default =1)"; } /ancillary_data/land/skill_snr_can_thrsh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_snr_can_thrsh"; String long_name "Threshold for signal-to-noise canopy score demerit"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "Threshold of signal-to-noise for canopy quality score demerit. (Default =0.5)"; } /ancillary_data/land/outlier_filter_switch { String HDF5_OBJ_FULLPATH "/ancillary_data/land/outlier_filter_switch"; String long_name "outlier_filter switch"; String units "1"; String source "ATBD Filter outlier noise"; String contentType "auxiliaryInformation"; String description "Controls entrance to the outlier filter subroutine. (Default = 1)"; } /ancillary_data/land/dragann_switch { String HDF5_OBJ_FULLPATH "/ancillary_data/land/dragann_switch"; String long_name "DRAGANN switch"; String units "1"; String source "ATBD \"Noise filtering via DRAGANN\""; String contentType "auxiliaryInformation"; String description "Controls entrance to the DRAGANN subroutine. (Default =1)"; } /ancillary_data/land/skill_telemratio_can_penalty { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_telemratio_can_penalty"; String long_name "Canopy score demerit value for telemetry band ratio"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "Canopy quality score demerit for telemetry band ratio. (Default =10)"; String units "1"; } /ancillary_data/land/proc_geoseg { String HDF5_OBJ_FULLPATH "/ancillary_data/land/proc_geoseg"; String long_name "Geosegment process interval length"; String units "1"; String source "Operations"; String contentType "auxiliaryInformation"; String description "Geosegment process interval length. This controls the amount read from ATL03 and ATL09 at a time. (Default = 500000)."; } /ancillary_data/land/skill_solarang_thrsh_can_1 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_solarang_thrsh_can_1"; String long_name "First threshold for solar angle canopy score demerit"; String units "degrees"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "First threshold of solar elevation angle for canopy quality score demerit. (Default =10.0)"; } /ancillary_data/land/can_stat_thresh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/can_stat_thresh"; String long_name "Threshold for canopy statistics"; String units "1"; String source "ATBD segment parameters for canopy products"; String contentType "auxiliaryInformation"; String description "Minimum percentage of canopy photons to compute statistics upon. (Default =0.05)"; } /ancillary_data/land/lseg { String HDF5_OBJ_FULLPATH "/ancillary_data/land/lseg"; String long_name "Long segment size"; String units "1"; String source "ATBD Preparing ATL03 data"; String contentType "auxiliaryInformation"; String description "Long segment size in number of 20 meter segments along ground track. (Default=500)"; } /ancillary_data/land/max_atl09files { String HDF5_OBJ_FULLPATH "/ancillary_data/land/max_atl09files"; String long_name "Maximum number of input ATL09s"; String units "1"; String source "Operations"; String contentType "auxiliaryInformation"; String description "Maximum number of input ATL09 files. (Default = 200)"; } /ancillary_data/land/skill_radmtry_thrsh_total_2 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_radmtry_thrsh_total_2"; String long_name "Second threshold for total radiometry score demerit"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "Second threshold of total radiometry for canopy quality score demerit. (Default =1.0)"; } /ancillary_data/land/skill_od_thrsh_te_1 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_od_thrsh_te_1"; String long_name "First threshold for optical depth terrain score demerit"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "First threshold of optical depth for terrain quality score demerit. (Default =0.2)"; } /ancillary_data/land/skill_radmtry_te_penalty_2 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_radmtry_te_penalty_2"; String long_name "Second terrain score demerit value for radiometry"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "Second terrain quality score demerit for radiometry. (Default =10)"; } /ancillary_data/land/skill_solarang_thrsh_te_2 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_solarang_thrsh_te_2"; String long_name "Second threshold for solar angle terrain score demerit"; String units "degrees"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "Second threshold of solar elevation angle for terrain quality score demerit. (Default =20.0)"; } /ancillary_data/land/skill_snr_te_penalty { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_snr_te_penalty"; String long_name "Terrain score demerit value for signal-to-noise"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "Terrain quality score demerit for signal-to-noise. (Default =10)"; } /ancillary_data/land/ref_dem_limit { String HDF5_OBJ_FULLPATH "/ancillary_data/land/ref_dem_limit"; String long_name "DEM threshold"; String units "meters"; String source "ATBD De-trend Data"; String contentType "auxiliaryInformation"; String description "Reference DEM limit used to reclassify signal as noise. (default = 120.0)"; } /ancillary_data/land/skill_telemratio_te_penalty { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_telemratio_te_penalty"; String long_name "Terrain score demerit value for telemetry band ratio"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "Terrain quality score demerit for telemetry band ratio. (Default =10)"; } /ancillary_data/land/skill_od_te_penalty_2 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_od_te_penalty_2"; String long_name "Second terrain score demerit value for optical depth"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "Second terrain quality score demerit for optical depth. (Default =10)"; } /ancillary_data/land/skill_snr_can_penalty { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_snr_can_penalty"; String long_name "Canopy score demerit value for signal-to-noise"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "Canopy quality score demerit for signal-to-noise ratio. (Default =10)"; } /ancillary_data/land/max_peaks { String HDF5_OBJ_FULLPATH "/ancillary_data/land/max_peaks"; String long_name "Maximum number of Gaussian peaks to fit in the data set"; String units "1"; String source "ATBD \"Noise filtering via DRAGANN\""; String contentType "auxiliaryInformation"; String description "Maximum number of Gaussian peaks to fit in the data set in DRAGANN. (Default =10)"; } /ancillary_data/land/skill_weakbeam_te_penalty { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_weakbeam_te_penalty"; String long_name "Terrain score demerit value for weak beam"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "Terrain quality score demerit for weak beam. (Default =5)"; } /ancillary_data/land/skill_snr_te_thrsh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_snr_te_thrsh"; String long_name "Threshold for signal-to-noise terrain score demerit"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "Threshold of signal-to-noise for terrain quality score demerit. (Default =0.5)"; } /ancillary_data/land/stat_thresh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/stat_thresh"; String long_name "Threshold for land statistics"; String units "1"; String source "ATBD Segment parameters for land products"; String contentType "auxiliaryInformation"; String description "Minimum number of photons to compute statistics upon. (Default =50)"; } /ancillary_data/land/skill_radmtry_total_penalty_1 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_radmtry_total_penalty_1"; String long_name "First canopy score demerit value for total radiometry"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "First canopy quality score demerit for total radiometry. (Default =5)"; } /ancillary_data/land/sig_rsq_search { String HDF5_OBJ_FULLPATH "/ancillary_data/land/sig_rsq_search"; String long_name "Square Radius of filter for canopy"; String units "meters^2"; String source "ATBD Find the top of canopy"; String contentType "auxiliaryInformation"; String description "Top of canopy refinement square search radius. (Default = 10000.0)"; } /ancillary_data/land/skill_weakbeam_can_penalty { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_weakbeam_can_penalty"; String long_name "Canopy score demerit value for weak beam"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "Canopy quality score demerit for weak beam. (Default =10)"; } /ancillary_data/land/skill_radmtry_thrsh_total_1 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_radmtry_thrsh_total_1"; String long_name "First threshold for total radiometry score demerit"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "First threshold of total radiometry for canopy quality score demerit. (Default =0.7)"; } /ancillary_data/land/del_amp { String HDF5_OBJ_FULLPATH "/ancillary_data/land/del_amp"; String long_name "Step Gaussian Amplitude optimization"; String units "1"; String source "ATBD \"Noise filtering via DRAGANN\""; String contentType "auxiliaryInformation"; String description "Step size for optimizing the amplitude variable of Gaussian function. (Default = 1.0)"; } /ancillary_data/land/sseg { String HDF5_OBJ_FULLPATH "/ancillary_data/land/sseg"; String long_name "Short Segment Length"; String units "meters"; String source "ATBD segment parameters for Land Products"; String contentType "auxiliaryInformation"; String description "Short segment length in meters. (Default = 100.0)"; } /ancillary_data/land/skill_od_thrsh_te_2 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_od_thrsh_te_2"; String long_name "Second threshold for optical depth terrain score demerit"; String units "1"; String source "ATBD Terrain Quality Score"; String contentType "auxiliaryInformation"; String description "Second threshold of optical depth for terrain quality score demerit. (Default =0.3)"; } /ancillary_data/land/skill_radmtry_total_penalty_2 { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_radmtry_total_penalty_2"; String long_name "Second canopy score demerit value for total radiometry"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "Second canopy quality score demerit for total radiometry. (Default =10)"; } /ancillary_data/land/skill_mswflag_can_thrsh { String HDF5_OBJ_FULLPATH "/ancillary_data/land/skill_mswflag_can_thrsh"; String long_name "Threshold for MSW flag canopy score demerit"; String units "1"; String source "ATBD Canopy Quality Score"; String contentType "auxiliaryInformation"; String description "Threshold of MSW flag for canopy quality score demerit. (Default =1)"; } /ancillary_data/land/shp_param { String HDF5_OBJ_FULLPATH "/ancillary_data/land/shp_param"; String long_name "Exponential coefficient for controlling the exponential decay of the filter window size as a function of number of signal photons."; String units "1"; String source "ATBD Compute Filtering Window"; String contentType "auxiliaryInformation"; String description "Exponential coefficient of the filter window size as a function. (Default = 21.0E-06)"; } /ancillary_data/land/del_sigma { String HDF5_OBJ_FULLPATH "/ancillary_data/land/del_sigma"; String long_name "Step size for optimizing the standard deviation parameter of Gaussian function."; String units "1"; String source "ATBD \"Noise filtering via DRAGANN\""; String contentType "auxiliaryInformation"; String description "Step size for optimizing the standard deviation parameter of Gaussian function. (Default = 0.5)"; } /ancillary_data/land/cloud_filter_switch { String HDF5_OBJ_FULLPATH "/ancillary_data/land/cloud_filter_switch"; String long_name "cloud_filter switch"; String units "1"; String source "ATBD Cloud based filtering"; String contentType "auxiliaryInformation"; String description "Controls entrance to the cloud_filter subroutine. (Default = 0)"; } /ancillary_data/land/n_dec_mode { String HDF5_OBJ_FULLPATH "/ancillary_data/land/n_dec_mode"; String long_name "Mode decimal parameter"; String units "1"; String source "ATBD segment_terrain_height_mode"; String contentType "auxiliaryInformation"; String description "Number of decimal places to consider in mode computation. (Default =1)"; } /ancillary_data/land/ref_finalground_limit { String HDF5_OBJ_FULLPATH "/ancillary_data/land/ref_finalground_limit"; String long_name "finalground threshold"; String units "meters"; String source "ATBD Final photon classification QA"; String contentType "auxiliaryInformation"; String description "Reference finalground limit used to reclassify signal as noise. (default = 150.0)"; } /ancillary_data/land/p_static { String HDF5_OBJ_FULLPATH "/ancillary_data/land/p_static"; String long_name "Dragann Parameter"; String units "1"; String source "ATBD \"Noise filtering via DRAGANN\""; String contentType "auxiliaryInformation"; String description "Parameter for controlling the search radius in nearest neighbor search in DRAGANN. (Default = 20)"; } /ancillary_data/start_delta_time { String HDF5_OBJ_FULLPATH "/ancillary_data/start_delta_time"; String long_name "ATLAS Start Time (Actual)"; String standard_name "time"; String units "seconds since 2018-01-01"; String source "Derived"; 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."; } /ancillary_data/start_geoseg { String HDF5_OBJ_FULLPATH "/ancillary_data/start_geoseg"; String long_name "Starting Geolocation Segment"; String units "1"; String source "Derived"; 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."; } /ancillary_data/start_orbit { String HDF5_OBJ_FULLPATH "/ancillary_data/start_orbit"; String long_name "Starting Orbit Number"; String units "1"; String source "Derived"; 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."; } /ancillary_data/data_start_utc { String HDF5_OBJ_FULLPATH "/ancillary_data/data_start_utc"; String long_name "Start UTC Time of Granule (CCSDS-A, Actual)"; String units "1"; String source "Derived"; String contentType "auxiliaryInformation"; String description "UTC (in CCSDS-A format) of the first data point within the granule."; } /ancillary_data/end_gpsweek { String HDF5_OBJ_FULLPATH "/ancillary_data/end_gpsweek"; String long_name "Ending GPSWeek of Granule (Actual)"; String contentType "auxiliaryInformation"; String description "GPS week number of the last data point in the granule."; String units "weeks from 1980-01-06"; String source "Derived"; } /ancillary_data/start_rgt { String HDF5_OBJ_FULLPATH "/ancillary_data/start_rgt"; String long_name "Starting Reference Groundtrack"; String units "1"; String source "Derived"; Int32 valid_min 1; Int32 valid_max 1387; 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."; } /ancillary_data/end_gpssow { String HDF5_OBJ_FULLPATH "/ancillary_data/end_gpssow"; String long_name "Ending GPS SOW of Granule (Actual)"; String units "seconds"; String source "Derived"; String contentType "auxiliaryInformation"; String description "GPS seconds-of-week of the last data point in the granule."; } /ancillary_data/qa_at_interval { String HDF5_OBJ_FULLPATH "/ancillary_data/qa_at_interval"; String long_name "QA Along-Track Interval"; String units "1"; String source "control"; String contentType "auxiliaryInformation"; String description "Statistics time interval for along-track QA data."; } /ancillary_data/start_region { String HDF5_OBJ_FULLPATH "/ancillary_data/start_region"; String long_name "Starting Region"; String units "1"; String source "Derived"; 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."; } /ancillary_data/start_gpsweek { String HDF5_OBJ_FULLPATH "/ancillary_data/start_gpsweek"; String long_name "Start GPSWeek of Granule (Actual)"; String units "weeks from 1980-01-06"; String source "Derived"; String contentType "auxiliaryInformation"; String description "GPS week number of the first data point in the granule."; } /gt3r/ { String HDF5_OBJ_FULLPATH "/gt3r/"; String atlas_pce "pce3"; String atlas_beam_type "weak"; String groundtrack_id "gt3r"; String atmosphere_profile "profile_3"; String atlas_spot_number "6"; String sc_orientation "Backward"; } /gt3r/land_segments/ { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/"; String description "Contains data categorized as land at 100 meter intervals."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt3r/land_segments/segment_watermask { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/segment_watermask"; String long_name "segment watermask"; String units "1"; String source "ATL08 ATBD segment_watermask"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Water mask(i.e. flag) indicating inland water as referenced from the Global Raster Water Mask(ANC33) at 250 m spatial resolution."; String coordinates "delta_time latitude longitude"; String flag_meanings "no_water water Undetermined"; Byte flag_values 0, 1, 255; } /gt3r/land_segments/delta_time_end { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/delta_time_end"; String long_name "delta time end"; String units "seconds since 2018-01-01"; String source "Derived (gps_seconds-gps_sec_offset)"; String contentType "referenceInformation"; String description "Time of the last photon contained within the data segment, in seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/latitude_20m { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/latitude_20m"; Float32 _FillValue 3.402823466e+38; String long_name "latitude of 20m segments"; String units "degree"; String source "ATBD Geosegment latitude"; Float32 valid_min -90.; Float32 valid_max 90.; String contentType "modelResult"; String description "Center latitude of 20m geosegments within each 100m land segment."; String coordinates "latitude longitude delta_time"; } /gt3r/land_segments/rgt { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/rgt"; String long_name "reference ground track"; String units "1"; String source "Operations"; Int16 valid_min 1; Int16 valid_max 1387; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt3r/land_segments/dem_flag { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/dem_flag"; String long_name "dem source flag"; String units "1"; String source "Atmosphere ATBD"; Int16 valid_min 0; Int16 valid_max 127; String contentType "referenceInformation"; String description "Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=Global, 3=MSS, 4=Antarctic."; String coordinates "delta_time latitude longitude"; String flag_meanings "none arctic global mss antarctic Undetermined"; Int16 flag_values 0, 1, 2, 3, 4, 127; } /gt3r/land_segments/msw_flag { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/msw_flag"; String long_name "multiple scattering warning flag"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 127; String contentType "qualityInformation"; String description "Multiple Scattering Warning flag. If no layers were detected, then msw_flag = 0. If blowing snow is detected and its estimated optical depth is greater than or equal to 0.5, then msw_flag = 5. If the blowing snow optical depth is less than 0.5, then msw_flag = 4. If no blowing snow is detected but there are cloud or aerosol layers detected, the msw_flag assumes values of 1 to 3 based on the height of the bottom of the lowest layer: < 1 km, msw_flag = 3; 1-3 km, msw_flag = 2; > 3km, msw_flag = 1. A value of 127 indicates that the signal to noise of the data was too low to reliably ascertain the presence of cloud or blowing snow. We expect values of 127 to occur only during daylight."; String coordinates "delta_time latitude longitude"; 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 127, 0, 1, 2, 3, 4, 5; } /gt3r/land_segments/permafrost_prob { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/permafrost_prob"; Int16 _FillValue 127; String long_name "permafrost probaility"; String standard_name "permafrost_prob"; String units "percent"; String source "ESA CCI, ANC47"; Int16 valid_min 0; Int16 valid_max 100; String contentType "referenceInformation"; String description "Permafrost probability (0 - 100) derived via percent of permafrost within pixel cell area in ESA CCI 2019 northern hemisphere permafrost dataset"; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/cloud_flag_atm { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/cloud_flag_atm"; Int16 _FillValue 127; String long_name "cloud flag atm"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 10; String contentType "qualityInformation"; String description "Cloud confidence flag from ATL09 that indicates the number of cloud or aerosol layers identified in each 25Hz atmospheric profile. If the flag is greater than 0, aerosols or clouds could be present. Valid range is 0 - 10."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/snr { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/snr"; Float32 _FillValue 3.402823466e+38; String long_name "signal to noise ratio"; String units "1"; String source "ATBD Noise filtering via DRAGANN"; String contentType "modelResult"; String description "The signal to noise ratio of geolocated photons as determined by the ratio of the superset of ATL03 signal and DRAGANN found signal photons used for processing the ATL08 segments to the background photons (i.e. noise) within the same ATL08 segments."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/canopy/ { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/"; String description "Contains height parameters based on the land algorithm."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt3r/land_segments/canopy/h_canopy { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/h_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "height canopy"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "98% height of all the individual canopy relative heights for the segment above the estimated terrain surface. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/canopy_rh_conf { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/canopy_rh_conf"; String units "1"; String long_name "canopy relative height confidence"; String source "Land/Veg ATBD Vegetation Parameters"; Int16 valid_min 0; Int16 valid_max 2; String contentType "modelResult"; String description "Canopy relative height confidence flag based on percentage of ground and canopy photons within a segment: 0 (<5% canopy), 1 (>5% canopy, <5% ground), 2 (>5% canopy, >5% ground)."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "<5%_canopy >=5%_canopy_<5%_ground >=5%_canopy_>=5%_ground"; Int16 flag_values 0, 1, 2; } /gt3r/land_segments/canopy/h_median_canopy_abs { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/h_median_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute segment median canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The median of individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/h_min_canopy { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/h_min_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "minimum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The minimum of relative individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/h_mean_canopy_abs { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/h_mean_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute mean canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Mean of the individual absolute canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/h_median_canopy { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/h_median_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "median canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The median of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. This parameter should be equivalent to RH50 reported in the literature."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/h_canopy_abs { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/h_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute segment canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The 98% height of all the absolute individual canopy heights referenced above the WGS84 ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/toc_roughness { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/toc_roughness"; Float32 _FillValue 3.402823466e+38; String long_name "top of canopy roughness"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Standard deviation of the relative heights of all photons classified as top of canopy within the segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/h_min_canopy_abs { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/h_min_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute minimum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The minimum of absolute individual canopy heights within segment referenced above the WGS84 Ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/h_dif_canopy { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/h_dif_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "canopy diff to median height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Difference between h_canopy and h_median_canopy"; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/h_canopy_quad { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/h_canopy_quad"; Float32 _FillValue 3.402823466e+38; String long_name "canopy quadratic mean"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The quadratic mean height of individual classified relative canopy photon heights above the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/h_canopy_20m { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/h_canopy_20m"; String units "m"; Float32 _FillValue 3.402823466e+38; String long_name "canopy height 20m"; String source "ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Canopy height for each 20m geosegment with each 100m land segment."; String coordinates "../latitude ../longitude ../delta_time"; } /gt3r/land_segments/canopy/n_ca_photons { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/n_ca_photons"; String long_name "number canopy photons"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The number of photons classified as canopy within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/photon_rate_can { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/photon_rate_can"; Float32 _FillValue 3.402823466e+38; String long_name "Canopy photon rate"; String units "s^-1"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Calculated photon rate of canopy photons within each 100m segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/centroid_height { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/centroid_height"; Float32 _FillValue 3.402823466e+38; String long_name "centroid height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Optical centroid of all photons classified as either canopy or ground points within the segment. The heights used in this calculation are absolute heights above the reference ellipsoid. This parameter is equivalent to the centroid height produced ICESat GLA14."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/canopy_h_metrics_abs { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/canopy_h_metrics_abs"; Float32 _FillValue 3.402823466e+38; String long_name "canopy absolute height metrics"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Height metrics based on the cumulative distribution of absolute canopy heights above the WGS84 Ellipsoid. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/can_noise { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/can_noise"; Float32 _FillValue 3.402823466e+38; String long_name "canopy noise rate"; String units "count/meter"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Number of noise photons calculated that fall within the canopy height for each 100 m segment based on ATL03 background rate parameters."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/h_mean_canopy { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/h_mean_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "mean canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Mean of individual relative canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/subset_can_flag { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/subset_can_flag"; Int16 _FillValue 127; String long_name "subset canopy flag"; String units "1"; String source "Land ATBD Vegetation Parameters"; Int16 valid_min -1; Int16 valid_max 1; String contentType "modelResult"; String description "Quality flag indicating the canopy photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "no_photon_data_within_geosegment no_canopy_photons_within_geosegment canopy_photons_present_within_geosegment"; Int16 flag_values -1, 0, 1; } /gt3r/land_segments/canopy/canopy_h_metrics { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/canopy_h_metrics"; Float32 _FillValue 3.402823466e+38; String long_name "canopy height metrics"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Height metrics based on the cumulative distribution of relative canopy heights above the interpolated ground surface. The height metrics are calculated at the following percentiles: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/n_toc_photons { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/n_toc_photons"; String long_name "number top of canopy photons"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "The number of photons classified as top of canopy within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/h_max_canopy_abs { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/h_max_canopy_abs"; Float32 _FillValue 3.402823466e+38; String long_name "absolute maximum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Maximum of individual absolute canopy heights within segment referenced above the WGS84 ellipsoid."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/h_canopy_uncertainty { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/h_canopy_uncertainty"; Float32 _FillValue 3.402823466e+38; String long_name "segment canopy height uncertainty"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "qualityInformation"; String description "Uncertainty of the relative canopy heights for the segment. Incorporates all systematic uncertainties as well as uncertainty from errors of identified photons. See section 1 and equations 1.4 and 1.5 of the ATL08 ATBD."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/photon_rate_can_nr { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/photon_rate_can_nr"; Float32 _FillValue 3.402823466e+38; String long_name "noise reduced number of canopy photons"; String units "s^-1"; String source "Land ATBD Vegetation Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Noise removed photon canopy rate within each 100 m segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/can_quality_score { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/can_quality_score"; String units "1"; String source "Land ATBD Vegetation Parameters"; Int16 valid_min 0; Int16 valid_max 100; String contentType "modelResult"; String description "Canopy quality score based on coincident conditions, from ATL08 ATBD section titled \"Canopy Quality Score\"."; String coordinates "../delta_time ../latitude ../longitude"; Int16 _FillValue 127; String long_name "canopy quality score"; } /gt3r/land_segments/canopy/canopy_openness { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/canopy_openness"; Float32 _FillValue 3.402823466e+38; String long_name "canopy openness"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Standard Deviation of all photons classified as canopy photons within the segment to provide inference of canopy openness."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/h_max_canopy { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/h_max_canopy"; Float32 _FillValue 3.402823466e+38; String long_name "maximum canopy height"; String units "meters"; String source "Land ATBD Vegetation Parameters"; String contentType "modelResult"; String description "Relative maximum of individual canopy heights within segment. Relative canopy heights have been computed by differencing the canopy photon height from the estimated terrain surface. Should be equivalent to RH100 metric reported in the literature."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/canopy/segment_cover { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/canopy/segment_cover"; Int16 _FillValue 32767; String long_name "canopy cover percentage"; String units "1"; String source "Land ATBD Vegetation Parameters"; String contentType "auxiliaryInformation"; String description "Average percentage value of the valid (value <= 100) Copernicus fractional cover product for each 100 m segment. This data is temporally static, and is the summation of forest and shrub land cover fractions. Source data from: https://land.copernicus.eu/en/products/global-dynamic-land-cover/copernicus-global-land-service-land-cover-100m-collection-3-epoch-2019-globe ."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/sigma_across { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/sigma_across"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas y"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Total cross-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_across. Sigma_atlas_y is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/terrain/ { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/"; String description "Contains terrain parameters at a 100m aggregation."; String data_rate "Data are stored as aggregates of 100 meters."; } /gt3r/land_segments/terrain/h_te_uncertainty { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/h_te_uncertainty"; Float32 _FillValue 3.402823466e+38; String long_name "uncertainty of h_te_mean"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Uncertainty of the mean terrain height for the segment. This uncertainty incorporates all systematic uncertainties(e.g. timing orbits, geolocation,etc.) as well as uncertainty from errors of identified photons. This parameter is described in section 1, equation 1.4 in ATL08 ATBD."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/terrain/h_te_mean { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/h_te_mean"; Float32 _FillValue 3.402823466e+38; String long_name "mean terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The mean of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/terrain/h_te_min { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/h_te_min"; Float32 _FillValue 3.402823466e+38; String long_name "minimum terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The minimum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/terrain/photon_rate_te { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/photon_rate_te"; Float32 _FillValue 3.402823466e+38; String long_name "Terrain photon rate"; String units "s^-1"; String source "Land ATBD Land Parameters"; Float32 valid_min 0.; String contentType "modelResult"; String description "Calculated photon rate of terrain photons within each 100m segment"; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/terrain/h_te_interp { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/h_te_interp"; Float32 _FillValue 3.402823466e+38; String long_name "interpolated terrain surface height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Interpolated terrain surface height above the WGS84 Ellipsoid at the midpoint of the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/terrain/h_te_max { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/h_te_max"; Float32 _FillValue 3.402823466e+38; String long_name "maximum terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The maximum of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/terrain/h_te_rh25 { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/h_te_rh25"; String units "meters"; Float32 _FillValue 3.402823466e+38; String long_name "Terrain height 25% percentile"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The terrain elevation from the 25% height. The classified ground photons are sorted into a cumulative distribution and the height associated with the 25% height for that segment is reported."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/terrain/h_te_skew { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/h_te_skew"; Float32 _FillValue 3.402823466e+38; String long_name "skew of terrain heights"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The skewness of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/terrain/h_te_best_fit_20m { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/h_te_best_fit_20m"; Float32 _FillValue 3.402823466e+38; String long_name "best fit 20m"; String units "m"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "Best fit terrain height to center of each 20m geosegment within each 100m land segment."; String coordinates "../latitude ../longitude ../delta_time"; } /gt3r/land_segments/terrain/h_te_median { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/h_te_median"; Float32 _FillValue 3.402823466e+38; String long_name "median terrain height"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The median of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/terrain/h_te_best_fit { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/h_te_best_fit"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain height best fit"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The best fit terrain elevation at the the mid-point location of each 100m segment. The mid-segment terrain elevation is determined by selecting the best of three fits- linear, 3rd order and 4th order polynomials - to the terrain photons and interpolating the elevation at the mid-point location of the 100 m segment. For the linear fit, a slope correction and weighting is applied to each ground photon based on the distance to the slope height at the center of the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/terrain/h_te_std { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/h_te_std"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain roughness"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The standard deviation of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/terrain/terrain_slope { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/terrain_slope"; Float32 _FillValue 3.402823466e+38; String long_name "segment terrain slope"; String units "1"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The along-track slope of terrain, within each segment;computed by a linear fit of terrain classified photons. Slope is in units of delta height over delta along track distance."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/terrain/subset_te_flag { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/subset_te_flag"; Int16 _FillValue 127; String long_name "subset terrain flag"; String units "1"; String source "Land ATBD Land Parameters"; Int16 valid_min -1; Int16 valid_max 1; String contentType "modelResult"; String description "Quality flag indicating the terrain photons populating the 100 m segment statistics are derived from less than 100 m worth of photons and/or less than 5 20m ATL03 segments."; String coordinates "../delta_time ../latitude ../longitude"; String flag_meanings "no_photon_data_within_geosegment no_terrain_photons_within_geosegment terrain_photons_present_within_geosegment"; Int16 flag_values -1, 0, 1; } /gt3r/land_segments/terrain/n_te_photons { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/n_te_photons"; String long_name "number of ground photons"; String units "1"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The number of the photons classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/terrain/h_te_mode { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/h_te_mode"; Float32 _FillValue 3.402823466e+38; String long_name "mode of terrain heights"; String units "meters"; String source "Land ATBD Land Parameters"; String contentType "modelResult"; String description "The mode of the photon heights above the WGS84 Ellipsoid, classified as terrain within the segment."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/terrain/te_quality_score { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain/te_quality_score"; Int16 _FillValue 127; String long_name "terrain quality score"; String units "1"; String source "Land ATBD Land Parameters"; Int16 valid_min 0; Int16 valid_max 100; String contentType "modelResult"; String description "Quality score based on coincident conditions, from ATL08 ATBD section titled \"Terrain Quality Score\"."; String coordinates "../delta_time ../latitude ../longitude"; } /gt3r/land_segments/layer_flag { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/layer_flag"; String long_name "consolidated cloud flag"; String units "1"; String source "ATL09"; String contentType "modelResult"; 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 coordinates "delta_time latitude longitude"; String flag_meanings "likely_clear likely_cloudy"; Int16 flag_values 0, 1; } /gt3r/land_segments/segment_snowcover { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/segment_snowcover"; String long_name "segment snowcover"; String units "1"; String source "ATL08 ATBD segment_snowcover"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Daily snow/ice cover from ATL09 at the 25 Hz rate(275m) indicating likely presence of snow and ice within each segment. 0=ice free water; 1=snow free land; 2=snow; 3=ice."; String coordinates "delta_time latitude longitude"; String flag_meanings "ice_free_water snow_free_land snow ice Undetermined"; Byte flag_values 0, 1, 2, 3, 255; } /gt3r/land_segments/beam_azimuth { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/beam_azimuth"; Float32 _FillValue 3.402823466e+38; String long_name "beam azimuth"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; String description "Azimuth(in radians) of the unit pointing vector for the reference photon in the local ENU frame in radians. The angle is measured from north and positive towards East."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/solar_azimuth { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/solar_azimuth"; String long_name "solar azimuth"; String units "degrees_east"; String source "ATL03 ATBD"; String contentType "referenceInformation"; String description "The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/psf_flag { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/psf_flag"; String long_name "point spread function flag"; String units "1"; String source "Land/Veg ATBD Refine Ground Estimates"; Byte valid_min 0; Byte valid_max 255; String contentType "referenceInformation"; String description "Flag is set to 1 if the point spread function (computed as sigma_atlas_land) has exceeded the threshold (1 m)"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt3r/land_segments/longitude { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/longitude"; String long_name "longitude"; String standard_name "longitude"; String units "degrees"; String source "Land ATBD segment parameters for Land Products"; Float32 valid_min -180.; Float32 valid_max 180.; String contentType "modelResult"; String description "Longitude of the center-most signal photon within each segment."; String coordinates "delta_time latitude"; } /gt3r/land_segments/latitude { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/latitude"; String long_name "latitude"; String standard_name "latitude"; String units "degrees"; String source "Land ATBD segment parameters for Land Products"; Float32 valid_min -90.; Float32 valid_max 90.; String contentType "modelResult"; String description "Latitude of the center-most signal photon within each segment."; String coordinates "delta_time longitude"; } /gt3r/land_segments/segment_id_end { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/segment_id_end"; String long_name "end geolocation segment bin"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Geolocation segment number of the last photon in the land segment."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/longitude_20m { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/longitude_20m"; Float32 _FillValue 3.402823466e+38; String long_name "longitude of 20m segments"; String units "degree"; String source "ATBD Geosegment longitude"; Float32 valid_min -180.; Float32 valid_max 180.; String contentType "modelResult"; String description "Center longitude of 20m geosegments within each 100m land segment."; String coordinates "latitude longitude delta_time"; } /gt3r/land_segments/surf_type { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/surf_type"; String long_name "surface type"; String units "1"; String source "ATL03 ATBD"; Int16 valid_min 0; Int16 valid_max 1; String contentType "referenceInformation"; String description "Flags describing which surface types this interval is associated with. 0=not type, 1=is type. Order of array is land, ocean, sea ice, land ice, inland water."; String coordinates "delta_time latitude longitude"; String flag_meanings "not_type is_type"; Int16 flag_values 0, 1; } /gt3r/land_segments/brightness_flag { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/brightness_flag"; String long_name "brightness flag"; String units "1"; String source "Land ATBD Brightness_flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "Flag indicating that the ground surface is bright (e.g. snow-covered or other bright surfaces)"; String coordinates "delta_time latitude longitude"; String flag_meanings "not_bright_surface bright_surface Undetermined"; Byte flag_values 0, 1, 255; } /gt3r/land_segments/segment_landcover { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/segment_landcover"; String long_name "segment landcover"; String units "1"; String source "ATL08 ATBD segment_landcover"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "UN-FAO Land Cover Surface type classification as reference from Copernicus Land Cover(ANC18) at the 100m resolution."; String coordinates "delta_time latitude longitude"; String flag_meanings "No_data Closed_forest_evergreen_needle_leaf Closed_forest_deciduous_needle_leaf Closed_forest_evergreen_broad_leaf Closed_forest_deciduous_broad_leaf Closed_forest_mixed Closed_forest_unknown Open_forest_evergreen_needle_leaf Open_forest_deciduous_needle_leaf Open_forest_evergreen_broad_leaf Open_forest_deciduous_broad_leaf Open_forest_mixed Open_forest_unknown Shrubs Herbaceous Herbaceous_wetleand Moss_and_lichen Bare_sparse_vegetation Cultivated_and_managed_vegetation_agriculture Urban_built_up Snow_and_ice Permanent_water_bodies Open_sea Undetermined"; Byte flag_values 0, 111, 113, 112, 114, 115, 116, 121, 123, 122, 124, 125, 126, 20, 30, 90, 100, 60, 40, 50, 70, 80, 200, 255; } /gt3r/land_segments/ph_removal_flag { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/ph_removal_flag"; String long_name "ph removal flag"; String units "1"; String source "ATBD Final photon classification QA"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Flag indicating more than ph_removal_percent_limit (default 50.0) removed from land segment due to failing QA tests"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt3r/land_segments/asr { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/asr"; Float32 _FillValue 3.402823466e+38; String long_name "apparent surface reflectance"; String units "1"; String source "ATL09"; String contentType "auxiliaryInformation"; String description "Apparent surface reflectance"; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/sigma_atlas_land { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/sigma_atlas_land"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas land"; String units "1"; String source "Land ATBD Refine Ground Estimates"; String contentType "referenceInformation"; String description "Total vertical geolocation error due to ranging and local surface slope. The parameter is computed for ATL08 as described in equation 1.2 ATL08 ATBD."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/segment_id_beg { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/segment_id_beg"; String long_name "begin geolocation segment bin"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Geolocation segment number of the first photon in the land segment."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/sigma_along { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/sigma_along"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas x"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Total along-track uncertainty due to PPD and POD knowledge. Read from ATL03 product gtx/geolocation/sigma_along. Sigma_atlas_x is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/dem_h { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/dem_h"; Float32 _FillValue 3.402823466e+38; String long_name "dem height"; String units "meters"; String source "Arctic, Antarctic, Global, MSS DEM"; String contentType "referenceInformation"; String description "Best available DEM (in priority of Arctic/Antarctic/Global/MSS) value at the geolocation point. Height is in meters above the WGS84 Ellipsoid."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/beam_coelev { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/beam_coelev"; Float32 _FillValue 3.402823466e+38; String long_name "beam co-elevation"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt3r/land_segments/sat_flag { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/sat_flag"; String long_name "saturation flag"; String units "1"; String source "ATL03, Land ATBD Saturation Flag"; Int16 valid_min -1; Int16 valid_max 127; String contentType "auxiliaryInformation"; String description "Flag derived from full_sat_fract on the ATL03 data product, averaged over 5 geosegments in 100m land segment"; String coordinates "delta_time latitude longitude"; String flag_meanings "no_saturation_detected saturation_detected not_enough_valid_data Undetermined"; Int16 flag_values 0, 1, -1, 127; } /gt3r/land_segments/sigma_topo { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/sigma_topo"; Float32 _FillValue 3.402823466e+38; String long_name "sigma atlas topo"; String units "1"; String source "Land ATBD Refine Ground Estimates"; String contentType "referenceInformation"; String description "Total uncertainty that include sigma_h plus geolocation uncertainty due to local slope (equation 1.3). The local slope is multiplied by the geolocation uncertainty factor. This will be used to determine the total vertical geolocation error due to ranging and local slope."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/night_flag { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/night_flag"; String long_name "night flag"; String units "1"; String source "Land ATBD Night_Flag"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Flag indicating the data were acquired in night conditions: 0=day, 1=night. Flag is derived from solar elevation at the geolocated segment. IF solar elevation is above threshold it is day, if not then it is night. Threshold is set in atlas_l3a_const_mod."; String coordinates "delta_time latitude longitude"; String flag_meanings "day night Undetermined"; Byte flag_values 0, 1, 255; } /gt3r/land_segments/delta_time_beg { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/delta_time_beg"; String long_name "delta time begin"; String units "seconds since 2018-01-01"; String source "Derived (gps_seconds-gps_sec_offset)"; String contentType "referenceInformation"; String description "Time of the first photon contained within the data segment, in seconds since the ATLAS SDP GPS Epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/sigma_h { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/sigma_h"; Float32 _FillValue 3.402823466e+38; String long_name "height uncertainty"; String units "1"; String source "ATL03"; String contentType "referenceInformation"; String description "Estimated uncertainty for the reference photon bounce point ellipsoid height: 1- sigma (m) provided at the geolocation segment rate on ATL03. Sigma_h is reported on ATL08 as the uncertainty of the center-most reference photon of the 100m ATL08 segment."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/last_seg_extend { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/last_seg_extend"; String long_name "last segment extended"; String standard_name "last_seg_extend"; String units "kilometers"; String source "Land ATBD Preparing ATL03 data for input"; String contentType "auxiliaryInformation"; String description "The distance (km) that the last ATL08 processing segment in a file is either extended or overlapped with the previous ATL08 processing segment."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/column_od_asr { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/column_od_asr"; Float32 _FillValue 3.402823466e+38; String long_name "Column optical depth from ASR"; String units "1"; String source "ATL09"; String contentType "auxiliaryInformation"; String description "Optical depth of atmosphere column based on apparent surface reflectance and the assumed actual surface reflectance."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/atlas_pa { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/atlas_pa"; Float32 _FillValue 3.402823466e+38; String long_name "atlas pointing angle"; String units "radians"; String source "ATL03"; String contentType "referenceInformation"; String description "Off nadir pointing angle (in radians) of the satellite to increase spatial sampling in the non-polar regions. ATLAS_PA =radians(90degs-beam_coelev)."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/ph_ndx_beg { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/ph_ndx_beg"; String long_name "photon index begin"; String units "1"; String source "Derived"; String contentType "auxiliaryInformation"; String description "Index (1-based) within the photon-rate data (/land_segments/photons) of the first photon within this each land segment."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/solar_elevation { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/solar_elevation"; String long_name "solar elevation"; String units "degrees"; String source "ATL03 ATBD"; String contentType "referenceInformation"; 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 coordinates "delta_time latitude longitude"; } /gt3r/land_segments/delta_time { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/delta_time"; String CLASS "DIMENSION_SCALE"; String long_name "mean_pass_time"; String standard_name "time"; String units "seconds since 2018-01-01"; String source "Land ATBD segment parameters for Land Products"; String contentType "referenceInformation"; String description "Mean time for the segment in number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed."; String coordinates "latitude longitude"; String NAME "delta_time"; } /gt3r/land_segments/cloud_fold_flag { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/cloud_fold_flag"; String long_name "cloud folding flag"; String units "1"; String source "ATL09"; Int16 valid_min 0; Int16 valid_max 127; String contentType "modelResult"; String description "Flag that indicates this profile likely contains cloud signal folded down from above 15 km to the last 2-3 km of the profile. See ATL09 ATBD Table 3.9 for detailed flag value meanings."; String coordinates "delta_time latitude longitude"; String flag_meanings "no_folding goes5_indicates profile_indicates both_indicate outside_limits"; Int16 flag_values 0, 1, 2, 3, 127; } /gt3r/land_segments/n_seg_ph { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/n_seg_ph"; String long_name "number of photons"; String units "1"; String source "Derived"; String contentType "auxiliaryInformation"; String description "Number of photons within each land segment."; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/terrain_flg { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/terrain_flg"; String long_name "terrain flag"; String units "1"; String source "Land ATBD Segment_terrain flag"; Byte valid_min 0; Byte valid_max 255; String contentType "auxiliaryInformation"; String description "Terrain flag quality check to indicate a deviation above a threshold from the reference DEM height reported on the product."; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt3r/land_segments/urban_flag { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/urban_flag"; String long_name "segment urban flag"; String units "1"; String source "Land ATBD Urban_flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "The urban flag indicates that a segment is likely located over an urban area as determined by coincident pixels in the Global Urban Footprint (GUF) 0.4 arcsecond product."; String coordinates "delta_time latitude longitude"; String flag_meanings "not_urban urban Undetermined"; Byte flag_values 0, 1, 255; } /gt3r/land_segments/permafrost_alt { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/permafrost_alt"; Float32 _FillValue 3.402823466e+38; String long_name "permafrost active layer thickness"; String standard_name "permafrost_alt"; String units "meters"; String source "ESA CCI, ANC47"; Float32 valid_min 0.; Float32 valid_max 100.; String contentType "referenceInformation"; String description "Permafrost active layer thickness (m) from ESA CCI 2019 northern hemisphere permafrost dataset"; String coordinates "delta_time latitude longitude"; } /gt3r/land_segments/dem_removal_flag { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/dem_removal_flag"; String long_name "dem removal flag"; String units "1"; String source "ATBD Segment reference DEM removal flag"; Byte valid_min 0; Byte valid_max 255; String contentType "qualityInformation"; String description "Flag indicating more than dem_removal_percent_limit (default 20.0) removed from land segment due to failing DEM-QA tests"; String coordinates "delta_time latitude longitude"; String flag_meanings "below_threshold above_threshold Undetermined"; Byte flag_values 0, 1, 255; } /gt3r/land_segments/h_dif_ref { String HDF5_OBJ_FULLPATH "/gt3r/land_segments/h_dif_ref"; Float32 _FillValue 3.402823466e+38; String long_name "h dif from reference"; String units "meters"; String source "Land ATBD segment parameters for Land Products"; String contentType "modelResult"; String description "Difference between h_te_median and ref_DEM"; String coordinates "delta_time latitude longitude"; } /gt3r/signal_photons/ { String HDF5_OBJ_FULLPATH "/gt3r/signal_photons/"; String description "Contains parameters related to individual photons."; String data_rate "Data are stored at the signal-photon classification rate."; } /gt3r/signal_photons/classed_pc_flag { String HDF5_OBJ_FULLPATH "/gt3r/signal_photons/classed_pc_flag"; String long_name "photon land atbd classification"; String units "1"; String source "Land ATBD Subgroup: Photons"; String contentType "modelResult"; String description "Land Vegetation ATBD classification flag for each photon as either noise, ground, canopy, and top of canopy. 0 = noise, 1 = ground, 2 = canopy, or 3 = top of canopy."; String coordinates "delta_time"; String flag_meanings "noise ground canopy top_of_canopy"; Int16 flag_values 0, 1, 2, 3; } /gt3r/signal_photons/classed_pc_indx { String HDF5_OBJ_FULLPATH "/gt3r/signal_photons/classed_pc_indx"; String units "1"; String long_name "indicies of classed photons"; String source "Retained from prior a_alt_science_ph packet"; String contentType "referenceInformation"; String description "Index (1-based) of the ATL08 classified signal photon from the start of the ATL03 geolocation segment specified on the ATL08 product at the photon rate in the corresponding parameter, ph_segment_id. This index traces back to specific photon within a 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group."; String coordinates "delta_time"; } /gt3r/signal_photons/ph_h { String HDF5_OBJ_FULLPATH "/gt3r/signal_photons/ph_h"; Float32 _FillValue 3.402823466e+38; String long_name "relative photon height"; String standard_name "height"; String units "meters"; String source "Land ATBD Subgroup: Photons"; String contentType "physicalMeasurement"; String description "Height of photons above interpolated land surface"; String coordinates "delta_time"; } /gt3r/signal_photons/d_flag { String HDF5_OBJ_FULLPATH "/gt3r/signal_photons/d_flag"; String long_name "dragann flag"; String units "1"; String source "Land ATBD Subgroup: Photons"; String contentType "qualityInformation"; String description "Flag indicating the labeling of DRAGANN noise filtering for a given photon."; String coordinates "delta_time"; String flag_meanings "noise signal"; Int16 flag_values 0, 1; } /gt3r/signal_photons/delta_time { String HDF5_OBJ_FULLPATH "/gt3r/signal_photons/delta_time"; String CLASS "DIMENSION_SCALE"; String NAME "delta_time"; String long_name "delta time"; String standard_name "time"; String units "seconds since 2018-01-01"; String source "ATL03"; String contentType "auxiliaryInformation"; 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."; } /gt3r/signal_photons/ph_segment_id { String HDF5_OBJ_FULLPATH "/gt3r/signal_photons/ph_segment_id"; String long_name "segment id of photon"; String units "1"; String source "Retained from prior a_alt_science_ph packet"; String contentType "referenceInformation"; String description "Segment ID of photons tracing back to specific 20m segment_id on ATL03. The unique identifier for tracing each ATL08 signal photon to the photon on ATL03 is the segment_id, orbit, and classed_pc_indx. The unique identifier for tracing each ATL08 signal photon to the corresponding photon record on ATL03 is the segment_id, orbit, cycle, and classed_pc_indx. Orbit and cycle intervals for the granule are found in the /ancillary_data. The timestamp of each orbit transition is found in the /orbit_info group."; String coordinates "delta_time"; } }