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

release[ 0..0] (Type is String)
- attributes
  - long_name: Release Number (Type is String)
  - units: 1 (Type is String)
  - source: Operations (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: Release number of the granule. The release number is incremented when the software or ancillary data used to create the granule has been changed. (Type is String)
end_geoseg[ 0..0] (Type is Int32)
- attributes
  - long_name: Ending Geolocation Segment (Type is String)
  - units: 1 (Type is String)
  - source: Derived (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: The ending geolocation segment number associated with the data contained within this granule. ICESat granule geographic regions are further refined by geolocation segments. During the geolocation process, a geolocation segment is created approximately every 20m from the start of the orbit to the end. The geolocation segments help align the ATLAS strong a weak beams and provide a common segment length for the L2 and higher products. The geolocation segment indices differ slightly from orbit-to-orbit because of the irregular shape of the Earth. The geolocation segment indices on ATL01 and ATL02 are only approximate because beams have not been aligned at the time of their creation. (Type is String)
version[ 0..0] (Type is String)
- attributes
  - long_name: Version (Type is String)
  - units: 1 (Type is String)
  - source: Operations (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: Version number of this granule within the release. It is a sequential number corresponding to the number of times the granule has been reprocessed for the current release. (Type is String)
end_region[ 0..0] (Type is Int32)
- attributes
  - long_name: Ending Region (Type is String)
  - units: 1 (Type is String)
  - source: Derived (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: The ending product-specific region number associated with the data contained within this granule. ICESat-2 data products are separated by geographic regions. The data contained within a specific region are the same for ATL01 and ATL02. ATL03 regions differ slightly because of different geolocation segment locations caused by the irregular shape of the Earth. The region indices for other products are completely independent. (Type is String)
atlas_sdp_gps_epoch[ 0..0] (Type is Float64)
- attributes
  - long_name: ATLAS Epoch Offset (Type is String)
  - units: seconds since 1980-01-06T00:00:00.000000Z (Type is String)
  - source: Operations (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: Number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS Standard Data Product (SDP) epoch (2018-01-01:T00.00.00.000000 UTC). Add this value to delta time parameters to compute full gps_seconds (relative to the GPS epoch) for each data point. (Type is String)
end_rgt[ 0..0] (Type is Int32)
- attributes
  - long_name: Ending Reference Groundtrack (Type is String)
  - units: 1 (Type is String)
  - source: Derived (Type is String)
  - valid_min: 1 (Type is Int32)
  - valid_max: 1387 (Type is Int32)
  - contentType: auxiliaryInformation (Type is String)
  - description: The ending reference groundtrack (RGT) number associated with the data contained within this granule. There are 1387 reference groundtrack in the ICESat-2 repeat orbit. The reference groundtrack increments each time the spacecraft completes a full orbit of the Earth and resets to 1 each time the spacecraft completes a full cycle. (Type is String)
end_delta_time[ 0..0] (Type is Float64)
- attributes
  - long_name: ATLAS End Time (Actual) (Type is String)
  - standard_name: time (Type is String)
  - units: seconds since 2018-01-01 (Type is String)
  - source: Derived (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: Number of GPS seconds since the ATLAS SDP epoch at the last data point in the file. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
end_orbit[ 0..0] (Type is Int32)
- attributes
  - long_name: Ending Orbit Number (Type is String)
  - units: 1 (Type is String)
  - source: Derived (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: The ending orbit number associated with the data contained within this granule. The orbit number increments each time the spacecraft completes a full orbit of the Earth. (Type is String)
start_cycle[ 0..0] (Type is Int32)
- attributes
  - long_name: Starting Cycle (Type is String)
  - units: 1 (Type is String)
  - source: Derived (Type is String)
  - valid_min: 0 (Type is Int32)
  - valid_max: 99 (Type is Int32)
  - contentType: auxiliaryInformation (Type is String)
  - description: The starting cycle number associated with the data contained within this granule. The cycle number is the counter of the number of 91-day repeat cycles completed by the mission. (Type is String)
data_end_utc[ 0..0] (Type is String)
- attributes
  - long_name: End UTC Time of Granule (CCSDS-A, Actual) (Type is String)
  - units: 1 (Type is String)
  - source: Derived (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: UTC (in CCSDS-A format) of the last data point within the granule. (Type is String)
control[ 0..0] (Type is String)
- attributes
  - long_name: Control File (Type is String)
  - units: 1 (Type is String)
  - source: Operations (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: PGE-specific control file used to generate this granule. To re-use, replace breaks (BR) with linefeeds. (Type is String)
start_gpssow[ 0..0] (Type is Float64)
- attributes
  - long_name: Start GPS SOW of Granule (Actual) (Type is String)
  - units: seconds (Type is String)
  - source: Derived (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: GPS seconds-of-week of the first data point in the granule. (Type is String)
granule_end_utc[ 0..0] (Type is String)
- attributes
  - long_name: End UTC Time of Granule (CCSDS-A, Requested) (Type is String)
  - units: 1 (Type is String)
  - source: Derived (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: Requested end time (in UTC CCSDS-A) of this granule. (Type is String)
end_cycle[ 0..0] (Type is Int32)
- attributes
  - long_name: Ending Cycle (Type is String)
  - units: 1 (Type is String)
  - source: Derived (Type is String)
  - valid_min: 0 (Type is Int32)
  - valid_max: 99 (Type is Int32)
  - contentType: auxiliaryInformation (Type is String)
  - description: The ending cycle number associated with the data contained within this granule. The cycle number is the counter of the number of 91-day repeat cycles completed by the mission. (Type is String)
granule_start_utc[ 0..0] (Type is String)
- attributes
  - long_name: Start UTC Time of Granule (CCSDS-A, Requested) (Type is String)
  - units: 1 (Type is String)
  - source: Derived (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: Requested start time (in UTC CCSDS-A) of this granule. (Type is String)
start_delta_time[ 0..0] (Type is Float64)
- attributes
  - long_name: ATLAS Start Time (Actual) (Type is String)
  - standard_name: time (Type is String)
  - units: seconds since 2018-01-01 (Type is String)
  - source: Derived (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: Number of GPS seconds since the ATLAS SDP epoch at the first data point in the file. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
start_geoseg[ 0..0] (Type is Int32)
- attributes
  - long_name: Starting Geolocation Segment (Type is String)
  - units: 1 (Type is String)
  - source: Derived (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: The starting geolocation segment number associated with the data contained within this granule. ICESat granule geographic regions are further refined by geolocation segments. During the geolocation process, a geolocation segment is created approximately every 20m from the start of the orbit to the end. The geolocation segments help align the ATLAS strong a weak beams and provide a common segment length for the L2 and higher products. The geolocation segment indices differ slightly from orbit-to-orbit because of the irregular shape of the Earth. The geolocation segment indices on ATL01 and ATL02 are only approximate because beams have not been aligned at the time of their creation. (Type is String)
start_orbit[ 0..0] (Type is Int32)
- attributes
  - long_name: Starting Orbit Number (Type is String)
  - units: 1 (Type is String)
  - source: Derived (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: The starting orbit number associated with the data contained within this granule. The orbit number increments each time the spacecraft completes a full orbit of the Earth. (Type is String)
data_start_utc[ 0..0] (Type is String)
- attributes
  - long_name: Start UTC Time of Granule (CCSDS-A, Actual) (Type is String)
  - units: 1 (Type is String)
  - source: Derived (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: UTC (in CCSDS-A format) of the first data point within the granule. (Type is String)
end_gpsweek[ 0..0] (Type is Int32)
- attributes
  - long_name: Ending GPSWeek of Granule (Actual) (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: GPS week number of the last data point in the granule. (Type is String)
  - units: weeks from 1980-01-06 (Type is String)
  - source: Derived (Type is String)
start_rgt[ 0..0] (Type is Int32)
- attributes
  - long_name: Starting Reference Groundtrack (Type is String)
  - units: 1 (Type is String)
  - source: Derived (Type is String)
  - valid_min: 1 (Type is Int32)
  - valid_max: 1387 (Type is Int32)
  - contentType: auxiliaryInformation (Type is String)
  - description: The starting reference groundtrack (RGT) number associated with the data contained within this granule. There are 1387 reference groundtrack in the ICESat-2 repeat orbit. The reference groundtrack increments each time the spacecraft completes a full orbit of the Earth and resets to 1 each time the spacecraft completes a full cycle. (Type is String)
end_gpssow[ 0..0] (Type is Float64)
- attributes
  - long_name: Ending GPS SOW of Granule (Actual) (Type is String)
  - units: seconds (Type is String)
  - source: Derived (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: GPS seconds-of-week of the last data point in the granule. (Type is String)
qa_at_interval[ 0..0] (Type is Float64)
- attributes
  - long_name: QA Along-Track Interval (Type is String)
  - units: seconds/cell (Type is String)
  - source: control (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: Statistics time interval for along-track QA data. (Type is String)
start_region[ 0..0] (Type is Int32)
- attributes
  - long_name: Starting Region (Type is String)
  - units: 1 (Type is String)
  - source: Derived (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: The starting product-specific region number associated with the data contained within this granule. ICESat-2 data products are separated by geographic regions. The data contained within a specific region are the same for ATL01 and ATL02. ATL03 regions differ slightly because of different geolocation segment locations caused by the irregular shape of the Earth. The region indices for other products are completely independent. (Type is String)
start_gpsweek[ 0..0] (Type is Int32)
- attributes
  - long_name: Start GPSWeek of Granule (Actual) (Type is String)
  - units: weeks from 1980-01-06 (Type is String)
  - source: Derived (Type is String)
  - contentType: auxiliaryInformation (Type is String)
  - description: GPS week number of the first data point in the granule. (Type is String)
land_ice(Type is Group)
- attributes
  - description: Contains land-ice-specific information ancillary to the data product. This may include product characteristics, instrument characteristics and/or processing constants. (Type is String)
- rbin_width[ 0..0] (Type is Float32)
  attributes
  
  long_name: Bin Size (Type is String)
  
  units: meters (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Residual histogram bin size (Type is String)
- sigma_beam[ 0..0] (Type is Float32)
  attributes
  
  long_name: Sigma of Gaussian Footprint (Type is String)
  
  units: meters (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Spatial sigma of the Gaussian footprint (m) (Type is String)
- qs_lim_hsigma[ 0..0] (Type is Float32)
  attributes
  
  long_name: Height Sigma QS Limit (Type is String)
  
  units: 1 (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: atl06_quality_summary limit for testing Height Sigma. (Type is String)
- fit_maxiter[ 0..0] (Type is Int32)
  attributes
  
  long_name: Maximum Iterations of Fit (Type is String)
  
  units: 1 (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Maximum number of iterations in at_seg_fit (Type is String)
- txp_maxiter[ 0..0] (Type is Int32)
  attributes
  
  long_name: Maximum Iterations (Type is String)
  
  units: counts (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Maximum number of iterations in tx_shape_corr (Type is String)
- qs_lim_hrs[ 0..0] (Type is Float32)
  attributes
  
  long_name: Height Robust Spread QS Limit (Type is String)
  
  units: meters (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: atl06_quality_summary limit for testing Height Robust Spread. (Type is String)
- qs_lim_bsc[ 0..0] (Type is Int32)
  attributes
  
  long_name: Blowing Snow Confidence QS Limit (Type is String)
  
  units: 1 (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: atl06_quality_summary limit for testing Blowing Snow Confidence. (Type is String)
- qs_lim_snr[ 0..0] (Type is Float32)
  attributes
  
  long_name: SNR Significance QS Limit (Type is String)
  
  units: 1 (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: atl06_quality_summary limit for testing SNR Significance. (Type is String)
- n_hist[ 0..0] (Type is Int32)
  attributes
  
  long_name: Number of Histogram Bins (Type is String)
  
  units: 1 (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Number of bins in a histogram (Type is String)
- min_gain_th[ 0..0] (Type is Float32)
  attributes
  
  long_name: Minimum Gain Threshold (Type is String)
  
  units: 1 (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Minimum estimated gain threshold (3.1.6) (Type is String)
- qs_lim_sss[ 0..0] (Type is Int32)
  attributes
  
  long_name: Signal Selection Source QS Limit (Type is String)
  
  units: 1 (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: atl06_quality_summary limit for testing Signal Selection Source. (Type is String)
- n_sigmas[ 0..0] (Type is Float32)
  attributes
  
  long_name: Number of Sigmas (Type is String)
  
  units: 1 (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Multiplied by sigma_expected to get h_win (Type is String)
- dt_hist[ 0..0] (Type is Float64)
  attributes
  
  long_name: Histogram Bin Size (Type is String)
  
  units: seconds (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Bin size for histograms (sec) (Type is String)
- sigma_tx[ 0..5] (Type is Float32)
  attributes
  
  long_name: Sigma Tx (Type is String)
  
  units: seconds (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: RDE of the Tx pulse in ATLAS Spot order (1-6). Calculated as half the difference between the 84th and 16th percentiles of the signal bins. (Type is String)
- min_signal_conf[ 0..0] (Type is Int32)
  attributes
  
  long_name: Minimum Signal Confidence (Type is String)
  
  units: 1 (Type is String)
  
  source: Operations (Type is String)
  
  valid_min: 0 (Type is Int32)
  
  valid_max: 4 (Type is Int32)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Minimum signal confidence level for a photon to be considered valid. (Type is String)
- t_dead[ 0..5] (Type is Float32)
  attributes
  
  long_name: Dead Time (Type is String)
  
  units: seconds (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Dead time, in ATLAS spot order (1-6). Calculated as the average of the CAL42 per-channel dead times, using the appropriate channels for strong and weak spots. (Type is String)
- qs_lim_msw[ 0..0] (Type is Int32)
  attributes
  
  long_name: Multiple Scattering Warning QS Limit (Type is String)
  
  units: 1 (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: atl06_quality_summary limit for testing Multiple Scattering Warning. (Type is String)
- min_n_sel[ 0..0] (Type is Int32)
  attributes
  
  long_name: Mininum Number of Photons (Type is String)
  
  units: 1 (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Minimum number of selected PEs in pe_select (Type is String)
- max_res_ids[ 0..0] (Type is Int32)
  attributes
  
  long_name: Max Segments (Type is String)
  
  units: 1 (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Maximum number of segment ids in each residual_histogram (Type is String)
- proc_interval[ 0..0] (Type is Int32)
  attributes
  
  long_name: Processing Interval (Type is String)
  
  units: seconds (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Processing interval in number of geolocation segments.. (Type is String)
- fpb_maxiter[ 0..0] (Type is Int32)
  attributes
  
  long_name: Maximum Iterations for FPB (Type is String)
  
  units: 1 (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Maximum number of iterations in fpb_corr (Type is String)
- min_n_pe[ 0..0] (Type is Int32)
  attributes
  
  long_name: Minimum Photons (Type is String)
  
  units: 1 (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Minimum # PEs for fit (Type is String)
- min_dist[ 0..0] (Type is Float32)
  attributes
  
  long_name: Minimum Distance (Type is String)
  
  units: meters (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Min dist between first and last selected PEs (Type is String)
- nhist_bins[ 0..0] (Type is Int32)
  attributes
  
  long_name: Number of Bins (Type is String)
  
  units: 1 (Type is String)
  
  source: Operations (Type is String)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Number of bins in residual histogram (Type is String)

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

qa_granule_fail_reason[ 0..0] (Type is Int32)
- attributes
  - long_name: Granule Failure Reason (Type is String)
  - units: 1 (Type is String)
  - source: Operations (Type is String)
  - valid_min: 0 (Type is Int32)
  - valid_max: 5 (Type is Int32)
  - contentType: qualityInformation (Type is String)
  - description: Flag indicating granule failure reason. 0=no failure; 1=processing error; 2=Insufficient output data was generated; 3=TBD Failure; 4=TBD_Failure; 5=other failure. (Type is String)
  - flag_meanings: no_failure PROCESS_ERROR INSUFFICIENT_OUTPUT failure_3 failure_4 OTHER_FAILURE (Type is String)
  - flag_values: 0, 1, 2, 3, 4, 5 (Type is Int32)
qa_granule_pass_fail[ 0..0] (Type is Int32)
- attributes
  - long_name: Granule Pass Flag (Type is String)
  - units: 1 (Type is String)
  - source: Operations (Type is String)
  - valid_min: 0 (Type is Int32)
  - valid_max: 1 (Type is Int32)
  - contentType: qualityInformation (Type is String)
  - description: Flag indicating granule quality. 0=granule passes automatic QA. 1=granule fails automatic QA. (Type is String)
  - flag_meanings: PASS FAIL (Type is String)
  - flag_values: 0, 1 (Type is Int32)
gt1r(Type is Group)
- attributes
  - description: Contains quality assessment data. This may include QA counters, QA along-track data and/or QA summary data. (Type is String)
Dimensions: [ /quality_assessment/gt1r/delta_time = 0..-1 ]
- lon_mean[ 0..-1] (Type is Float64)
  attributes
  
  long_name: Longitude Mean (Type is String)
  
  standard_name: longitude (Type is String)
  
  units: degrees_east (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  valid_min: -180. (Type is Float64)
  
  valid_max: 180. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean longitude of the 10km segment. (Type is String)
  
  coordinates: delta_time lat_mean (Type is String)
- lat_mean[ 0..-1] (Type is Float64)
  attributes
  
  long_name: Latitude Mean (Type is String)
  
  standard_name: latitude (Type is String)
  
  units: degrees_north (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  valid_min: -90. (Type is Float64)
  
  valid_max: 90. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean latitude of the 10km segment. (Type is String)
  
  coordinates: delta_time lon_mean (Type is String)
- delta_time[ /quality_assessment/gt1r/delta_time= 0..-1] (Type is Float64)
  attributes
  
  long_name: Elapsed GPS seconds (Type is String)
  
  standard_name: time (Type is String)
  
  units: seconds since 2018-01-01 (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Mean number of GPS seconds since the ATLAS SDP epoch for the 10km segment. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
  
  coordinates: lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_0[ 0..-1] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 0 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to zero. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_2[ 0..-1] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 2 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 2. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_1[ 0..-1] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 1 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 1. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_3[ 0..-1] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 3 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 3. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
gt2r(Type is Group)
- attributes
  - description: Contains quality assessment data. This may include QA counters, QA along-track data and/or QA summary data. (Type is String)
Dimensions: [ /quality_assessment/gt2r/delta_time = 0..-1 ]
- lon_mean[ 0..-1] (Type is Float64)
  attributes
  
  long_name: Longitude Mean (Type is String)
  
  standard_name: longitude (Type is String)
  
  units: degrees_east (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  valid_min: -180. (Type is Float64)
  
  valid_max: 180. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean longitude of the 10km segment. (Type is String)
  
  coordinates: delta_time lat_mean (Type is String)
- delta_time[ /quality_assessment/gt2r/delta_time= 0..-1] (Type is Float64)
  attributes
  
  long_name: Elapsed GPS seconds (Type is String)
  
  standard_name: time (Type is String)
  
  units: seconds since 2018-01-01 (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Mean number of GPS seconds since the ATLAS SDP epoch for the 10km segment. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
  
  coordinates: lat_mean lon_mean (Type is String)
- lat_mean[ 0..-1] (Type is Float64)
  attributes
  
  long_name: Latitude Mean (Type is String)
  
  standard_name: latitude (Type is String)
  
  units: degrees_north (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  valid_min: -90. (Type is Float64)
  
  valid_max: 90. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean latitude of the 10km segment. (Type is String)
  
  coordinates: delta_time lon_mean (Type is String)
- signal_selection_source_fraction_0[ 0..-1] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 0 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to zero. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_2[ 0..-1] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 2 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 2. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_1[ 0..-1] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 1 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 1. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_3[ 0..-1] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 3 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 3. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
gt1l(Type is Group)
- attributes
  - description: Contains quality assessment data. This may include QA counters, QA along-track data and/or QA summary data. (Type is String)
Dimensions: [ /quality_assessment/gt1l/delta_time = 0..-1 ]
- lon_mean[ 0..-1] (Type is Float64)
  attributes
  
  long_name: Longitude Mean (Type is String)
  
  standard_name: longitude (Type is String)
  
  units: degrees_east (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  valid_min: -180. (Type is Float64)
  
  valid_max: 180. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean longitude of the 10km segment. (Type is String)
  
  coordinates: delta_time lat_mean (Type is String)
- lat_mean[ 0..-1] (Type is Float64)
  attributes
  
  long_name: Latitude Mean (Type is String)
  
  standard_name: latitude (Type is String)
  
  units: degrees_north (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  valid_min: -90. (Type is Float64)
  
  valid_max: 90. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean latitude of the 10km segment. (Type is String)
  
  coordinates: delta_time lon_mean (Type is String)
- delta_time[ /quality_assessment/gt1l/delta_time= 0..-1] (Type is Float64)
  attributes
  
  long_name: Elapsed GPS seconds (Type is String)
  
  standard_name: time (Type is String)
  
  units: seconds since 2018-01-01 (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Mean number of GPS seconds since the ATLAS SDP epoch for the 10km segment. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
  
  coordinates: lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_0[ 0..-1] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 0 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to zero. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_2[ 0..-1] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 2 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 2. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_1[ 0..-1] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 1 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 1. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_3[ 0..-1] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 3 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 3. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
gt3l(Type is Group)
- attributes
  - description: Contains quality assessment data. This may include QA counters, QA along-track data and/or QA summary data. (Type is String)
Dimensions: [ /quality_assessment/gt3l/delta_time = 0..21 ]
- lon_mean[ /quality_assessment/gt3l/delta_time= 0..21] (Type is Float64)
  attributes
  
  long_name: Longitude Mean (Type is String)
  
  standard_name: longitude (Type is String)
  
  units: degrees_east (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  valid_min: -180. (Type is Float64)
  
  valid_max: 180. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean longitude of the 10km segment. (Type is String)
  
  coordinates: delta_time lat_mean (Type is String)
- delta_time[ /quality_assessment/gt3l/delta_time= 0..21] (Type is Float64)
  attributes
  
  long_name: Elapsed GPS seconds (Type is String)
  
  standard_name: time (Type is String)
  
  units: seconds since 2018-01-01 (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Mean number of GPS seconds since the ATLAS SDP epoch for the 10km segment. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
  
  coordinates: lat_mean lon_mean (Type is String)
- lat_mean[ /quality_assessment/gt3l/delta_time= 0..21] (Type is Float64)
  attributes
  
  long_name: Latitude Mean (Type is String)
  
  standard_name: latitude (Type is String)
  
  units: degrees_north (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  valid_min: -90. (Type is Float64)
  
  valid_max: 90. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean latitude of the 10km segment. (Type is String)
  
  coordinates: delta_time lon_mean (Type is String)
- signal_selection_source_fraction_0[ /quality_assessment/gt3l/delta_time= 0..21] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 0 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to zero. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_2[ /quality_assessment/gt3l/delta_time= 0..21] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 2 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 2. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_1[ /quality_assessment/gt3l/delta_time= 0..21] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 1 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 1. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_3[ /quality_assessment/gt3l/delta_time= 0..21] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 3 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 3. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
gt2l(Type is Group)
- attributes
  - description: Contains quality assessment data. This may include QA counters, QA along-track data and/or QA summary data. (Type is String)
Dimensions: [ /quality_assessment/gt2l/delta_time = 0..-1 ]
- lon_mean[ 0..-1] (Type is Float64)
  attributes
  
  long_name: Longitude Mean (Type is String)
  
  standard_name: longitude (Type is String)
  
  units: degrees_east (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  valid_min: -180. (Type is Float64)
  
  valid_max: 180. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean longitude of the 10km segment. (Type is String)
  
  coordinates: delta_time lat_mean (Type is String)
- delta_time[ /quality_assessment/gt2l/delta_time= 0..-1] (Type is Float64)
  attributes
  
  long_name: Elapsed GPS seconds (Type is String)
  
  standard_name: time (Type is String)
  
  units: seconds since 2018-01-01 (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Mean number of GPS seconds since the ATLAS SDP epoch for the 10km segment. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
  
  coordinates: lat_mean lon_mean (Type is String)
- lat_mean[ 0..-1] (Type is Float64)
  attributes
  
  long_name: Latitude Mean (Type is String)
  
  standard_name: latitude (Type is String)
  
  units: degrees_north (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  valid_min: -90. (Type is Float64)
  
  valid_max: 90. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean latitude of the 10km segment. (Type is String)
  
  coordinates: delta_time lon_mean (Type is String)
- signal_selection_source_fraction_0[ 0..-1] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 0 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to zero. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_2[ 0..-1] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 2 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 2. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_1[ 0..-1] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 1 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 1. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_3[ 0..-1] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 3 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 3. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
gt3r(Type is Group)
- attributes
  - description: Contains quality assessment data. This may include QA counters, QA along-track data and/or QA summary data. (Type is String)
Dimensions: [ /quality_assessment/gt3r/delta_time = 0..21 ]
- lon_mean[ /quality_assessment/gt3r/delta_time= 0..21] (Type is Float64)
  attributes
  
  long_name: Longitude Mean (Type is String)
  
  standard_name: longitude (Type is String)
  
  units: degrees_east (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  valid_min: -180. (Type is Float64)
  
  valid_max: 180. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean longitude of the 10km segment. (Type is String)
  
  coordinates: delta_time lat_mean (Type is String)
- delta_time[ /quality_assessment/gt3r/delta_time= 0..21] (Type is Float64)
  attributes
  
  long_name: Elapsed GPS seconds (Type is String)
  
  standard_name: time (Type is String)
  
  units: seconds since 2018-01-01 (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Mean number of GPS seconds since the ATLAS SDP epoch for the 10km segment. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
  
  coordinates: lat_mean lon_mean (Type is String)
- lat_mean[ /quality_assessment/gt3r/delta_time= 0..21] (Type is Float64)
  attributes
  
  long_name: Latitude Mean (Type is String)
  
  standard_name: latitude (Type is String)
  
  units: degrees_north (Type is String)
  
  source: Section 7.2, Q/A Statistics (Type is String)
  
  valid_min: -90. (Type is Float64)
  
  valid_max: 90. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean latitude of the 10km segment. (Type is String)
  
  coordinates: delta_time lon_mean (Type is String)
- signal_selection_source_fraction_0[ /quality_assessment/gt3r/delta_time= 0..21] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 0 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to zero. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_2[ /quality_assessment/gt3r/delta_time= 0..21] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 2 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 2. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_1[ /quality_assessment/gt3r/delta_time= 0..21] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 1 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 1. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- signal_selection_source_fraction_3[ /quality_assessment/gt3r/delta_time= 0..21] (Type is Float32)
  attributes
  
  long_name: Signal Selection Source Fraction 3 (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Q/A Statistics (Type is String)
  
  valid_min: 0. (Type is Float32)
  
  valid_max: 1. (Type is Float32)
  
  contentType: qualityInformation (Type is String)
  
  description: The fraction of 20m segments with signal_selection_source equal to 3. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)

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

iso_19139_dataset_xml[ 0..0] (Type is String)
- attributes
  - long_name: ISO 19139 Dataset XML (Type is String)
  - description: ISO 19139 Dataset XML (Type is String)
iso_19139_series_xml[ 0..0] (Type is String)
- attributes
  - long_name: ISO 19139 Series XML (Type is String)
  - description: ISO 19139 Series XML (Type is String)
AcquisitionInformation(Type is Group)

no attributes
- lidar(Type is Group)
  attributes
  
  pulse_rate: 10000 pps (Type is String)
  
  wavelength: 532 nm (Type is String)
  
  identifier: ATLAS (Type is String)
  
  type: Laser Altimeter (Type is String)
  
  description: ATLAS on ICESat-2 determines the range between the satellite and the Earth's surface by measuring the two-way time delay of short pulses of laser light that it transmits in six beams. It is different from previous operational ice-sheet altimeters in that it is a photon-counting LIDAR. ATLAS records a set of arrival times for individual photons, which are then analyzed to derive surface, vegetation, and cloud properties. ATLAS has six beams arranged in three pairs, so that it samples each of three reference pair tracks with a pair of beams; ATLAS transmits pulses at 10 kHz, giving approximately one pulse every 0.7 m along track; ATLAS's expected pointing control will be better than 90 m RMS. (Type is String)
- lidarDocument(Type is Group)
  attributes
  
  edition: Pre-Release (Type is String)
  
  publicationDate: 12/31/17 (Type is String)
  
  title: A document describing the ATLAS instrument will be provided by the ICESat-2 Project Science Office. (Type is String)
- platform(Type is Group)
  attributes
  
  identifier: ICESat-2 (Type is String)
  
  description: Ice, Cloud, and land Elevation Satellite-2 (Type is String)
  
  type: Spacecraft (Type is String)
- platformDocument(Type is Group)
  attributes
  
  edition: 31-Dec-16 (Type is String)
  
  publicationDate: 31-Dec-16 (Type is String)
  
  title: The Ice, Cloud, and land Elevation Satellite-2 (ICESat-2): Science requirements, concept, and implementation. Thorsten Markus, Tom Neumann, Anthony Martino, Waleed Abdalati, Kelly Brunt, Beata Csatho, Sinead Farrell, Helen Fricker, Alex Gardner, David Harding, Michael Jasinski, Ron Kwok, Lori Magruder, Dan Lubin, Scott Luthcke, James Morison, Ross Nelson, Amy Neuenschwander, Stephen Palm, Sorin Popescu, CK Shum, Bob E. Schutz, Benjamin Smith, Yuekui Yang, Jay Zwally. http://dx.doi.org/10.1016/j.rse.2016.12.029 (Type is String)
DataQuality(Type is Group)
- attributes
  - scope: NOT_SET (Type is String)
- CompletenessOmission(Type is Group)
  attributes
  
  evaluationMethodType: directInternal (Type is String)
  
  measureDescription: TBD (Type is String)
  
  nameOfMeasure: TBD (Type is String)
  
  unitofMeasure: TBD (Type is String)
  
  value: NOT_SET (Type is String)
- DomainConsistency(Type is Group)
  attributes
  
  evaluationMethodType: directInternal (Type is String)
  
  measureDescription: TBD (Type is String)
  
  nameOfMeasure: TBD (Type is String)
  
  unitofMeasure: TBD (Type is String)
  
  value: NOT_SET (Type is String)
ProductSpecificationDocument(Type is Group)
- attributes
  - ShortName: ATL06_SDP (Type is String)
  - characterSet: utf8 (Type is String)
  - language: eng (Type is String)
  - publicationDate: Feb 2020 (Type is String)
  - title: ICESat-2-SIPS-SPEC-4260 - ATLAS Science Algorithm Standard Data Product (SDP) Volume 5 (ATL06). (Type is String)
  - edition: v4.3 (Type is String)
SeriesIdentification(Type is Group)
- attributes
  - maintenanceAndUpdateFrequency: asNeeded (Type is String)
  - maintenanceDate: SET_BY_META (Type is String)
  - VersionID: 007 (Type is String)
  - language: eng (Type is String)
  - characterSet: utf8 (Type is String)
  - pointOfContact: NSIDC DAAC > NASA National Snow and Ice Data Center Distributed Active Archive Center (Type is String)
  - longName: ATLAS/ICESat-2 L3A Land Ice Height (Type is String)
  - shortName: ATL06 (Type is String)
  - identifier_product_DOI: doi:10.5067/ATLAS/ATL06.007 (Type is String)
  - revisionDate: 2022-08-09 (Type is String)
  - resourceProviderOrganizationName: National Aeronautics and Space Administration (NASA) (Type is String)
  - abstract: ATL06 provides estimates of the ice-sheet mean surface height relative to the WGS-84 ellipsoid, and ancillary parameters needed to interpret and assess the quality of these height estimates. (Type is String)
  - purpose: ATL06 provides estimates of the ice-sheet mean surface height relative to the WGS-84 ellipsoid, and ancillary parameters needed to interpret and assess the quality of these height estimates. (Type is String)
  - credit: The software that generates the ATL06 product was designed and implemented at the NASA Wallops Flight Facility in Wallops Island, Virginia. (Type is String)
  - status: onGoing (Type is String)
  - format: HDF (Type is String)
  - formatVersion: 5 (Type is String)
  - topicCategory: geoscientificInformation (Type is String)
  - mission: ICESat-2 > Ice, Cloud, and land Elevation Satellite-2 (Type is String)
DatasetIdentification(Type is Group)
- attributes
  - spatialRepresentationType: along-track (Type is String)
  - creationDate: 2025-12-19T22:01:54.000000Z (Type is String)
  - uuid: fe870c8f-7533-3a33-8c17-d667ecdd83b6 (Type is String)
  - fileName: ATL06_20250913142324_13722807_007_01.h5 (Type is String)
  - VersionID: 007 (Type is String)
  - language: eng (Type is String)
  - characterSet: utf8 (Type is String)
  - shortName: ATL06 (Type is String)
  - originatorOrganizationName: GSFC I-SIPS > ICESat-2 Science Investigator-led Processing System (Type is String)
  - abstract: ATL06 provides estimates of the ice-sheet mean surface height relative to the WGS-84 ellipsoid, and ancillary parameters needed to interpret and assess the quality of these height estimates. (Type is String)
  - purpose: ATL06 provides estimates of the ice-sheet mean surface height relative to the WGS-84 ellipsoid, and ancillary parameters needed to interpret and assess the quality of these height estimates. (Type is String)
  - credit: The software that generates the ATL06 product was designed and implemented at the NASA Wallops Flight Facility in Wallops Island, Virginia. (Type is String)
  - status: onGoing (Type is String)
  - topicCategory: geoscientificInformation (Type is String)
Extent(Type is Group)
- attributes
  - northBoundLatitude: 25.51268125829365 (Type is Float64)
  - eastBoundLongitude: -171.42503689992421 (Type is Float64)
  - southBoundLatitude: 25.474481959584711 (Type is Float64)
  - westBoundLongitude: -171.42912310348692 (Type is Float64)
  - rangeBeginningDateTime: 2025-09-13T14:23:47.485874Z (Type is String)
  - rangeEndingDateTime: 2025-09-13T14:23:48.254371Z (Type is String)
QADatasetIdentification(Type is Group)
- attributes
  - creationDate: 2025-12-19T22:01:57.000000Z (Type is String)
  - abstract: An ASCII product that contains statistical information on data product results. These statistics enable data producers and users to assess the quality of the data in the data product granule (Type is String)
  - fileName: ATL06_20250913142324_13722807_007_01.qa (Type is String)
Lineage(Type is Group)

no attributes
- ANC36-06(Type is Group)
  attributes
  
  description: ISO 19139 XML file containing Series-level metadata information. (Type is String)
  
  fileName: ANC36-06_20250523205141_007_01.xml (Type is String)
  
  shortName: ANC36-06 (Type is String)
  
  uuid: f486c1c2-b893-34c1-b902-1a59f2688c66 (Type is String)
  
  version: 007 (Type is String)
- Control(Type is Group)
  attributes
  
  description: Text-based keyword=value file generated automatically within the ICESat-2 data system that specifies all of the conditions required for each individual run of the software. (Type is String)
  
  fileName: CTL_atlas_l3a_is_021426921.ctl (Type is String)
  
  shortName: CNTL (Type is String)
  
  version: 1 (Type is String)
- ANC28(Type is Group)
  attributes
  
  description: DTU Mean Sea Surface re-referenced to the WGS84 ellipsoid. (Type is String)
  
  fileName: dtu13_20180705_001_01.nc (Type is String)
  
  shortName: ANC28 (Type is String)
  
  uuid: 56f47040-a72e-3109-99c2-bc1658e6dda4 (Type is String)
  
  version: 20180705 (Type is String)
- ANC38-06(Type is Group)
  attributes
  
  description: ISO 19139 XML file containing DataSet-level metadata information. (Type is String)
  
  fileName: ANC38-06_20250523205142_007_01.xml (Type is String)
  
  shortName: ANC38-06 (Type is String)
  
  uuid: f8d47ee3-4f43-3070-a6b0-f05ef6bd3cb2 (Type is String)
  
  version: 007 (Type is String)
- ANC06-02(Type is Group)
  attributes
  
  description: ArcticDEM 32m Digital Elevation Model reformatted into HDF5. (Type is String)
  
  fileName: arcticdem32m_20190611_001_01.h5 (Type is String)
  
  shortName: ANC06-02 (Type is String)
  
  uuid: ce07ef72-0bf4-353b-8475-fb568b029905 (Type is String)
  
  version: 20190611 (Type is String)
- ANC06-03(Type is Group)
  attributes
  
  description: REMA Antarctica 100m Digital Elevation Model filled and reformatted into HDF5 (Type is String)
  
  fileName: atl06rema100m_20190628_001_01.h5 (Type is String)
  
  shortName: ANC06-03 (Type is String)
  
  uuid: 3e0a81bd-bbd5-35fa-b868-3254f9355b7f (Type is String)
  
  version: 20190628 (Type is String)
- ANC25-06(Type is Group)
  attributes
  
  description: HDF5 template file that defines the organization and default content of the product. (Type is String)
  
  fileName: ANC25-06_20250523205529_051_01.h5 (Type is String)
  
  shortName: ANC25-06 (Type is String)
  
  uuid: 45545701-8dcb-30dc-9f21-e2ee4e77fe87 (Type is String)
  
  version: 051 (Type is String)
- ANC17(Type is Group)
  attributes
  
  description: Land Ice Height SNR Significance Table (Type is String)
  
  fileName: anc17_snr_f_20180626_001_01.h5 (Type is String)
  
  shortName: ANC17 (Type is String)
  
  uuid: 10e264bc-139a-3737-9f92-29e64e9b858c (Type is String)
  
  version: 20180626 (Type is String)
- ANC26-06(Type is Group)
  attributes
  
  description: HDF5 template file that defines the organization and default content of the product metadata. (Type is String)
  
  fileName: ANC26-06_20250523205537_051_01.h5 (Type is String)
  
  shortName: ANC26-06 (Type is String)
  
  uuid: 438c292c-43ce-3b04-9c33-683805c75ca5 (Type is String)
  
  version: 051 (Type is String)
- ATL03(Type is Group)
  attributes
  
  description: ICESat-2 ATLAS L2A Global Geolocated Photon data products. (Type is String)
  
  fileName: ATL03_20250913142324_13722807_007_01.h5 (Type is String)
  
  shortName: ATL03 (Type is String)
  
  uuid: c48e4feb-e9c5-3553-bdfe-a1a6e367be23 (Type is String)
  
  version: 007 (Type is String)
  
  start_cycle: 28 (Type is Int32)
  
  end_cycle: 28 (Type is Int32)
  
  start_orbit: 39022 (Type is Int32)
  
  end_orbit: 39022 (Type is Int32)
  
  start_rgt: 1372 (Type is Int32)
  
  end_rgt: 1372 (Type is Int32)
  
  start_region: 7 (Type is Int32)
  
  end_region: 7 (Type is Int32)
  
  start_geoseg: 852091 (Type is Int32)
  
  end_geoseg: 1001793 (Type is Int32)
- ATL09(Type is Group)
  attributes
  
  description: ICESat-2 ATLAS L3A atmosphere data products. (Type is String)
  
  fileName: ATL09_20250913134322_13722801_007_01.h5 (Type is String)
  
  shortName: ATL09 (Type is String)
  
  uuid: 758cce16-d1d5-3c1c-819f-88e47f7c36e1 (Type is String)
  
  version: 007 (Type is String)
  
  start_cycle: 28 (Type is Int32)
  
  end_cycle: 28 (Type is Int32)
  
  start_orbit: 39022 (Type is Int32)
  
  end_orbit: 39022 (Type is Int32)
  
  start_rgt: 1372 (Type is Int32)
  
  end_rgt: 1372 (Type is Int32)
  
  start_region: 1 (Type is Int32)
  
  end_region: 14 (Type is Int32)
  
  start_geoseg: 2 (Type is Int32)
  
  end_geoseg: 2007136 (Type is Int32)
- ANC06-01(Type is Group)
  attributes
  
  description: MERIT 3 arcsec Digital Elevation Model reformatted into HDF5 and re-referenced to the WGS-84 ellipsoid. (Type is String)
  
  fileName: merit_3as_20200617_001_01.h5 (Type is String)
  
  shortName: ANC06-01 (Type is String)
  
  uuid: 3db8ab65-d2ac-37c7-86db-17c762268673 (Type is String)
  
  version: 20200617 (Type is String)
- ANC19(Type is Group)
  attributes
  
  description: TAI to UTC leapsecond file retrieved from ftp://maia.usno.navy.mil/ser7/tai-utc.dat (Type is String)
  
  fileName: tai_utc_2017.dat (Type is String)
  
  shortName: ANC19 (Type is String)
  
  uuid: 7c66d365-278a-31f7-8fe4-9c80e2f012e5 (Type is String)
  
  version: 001 (Type is String)
ProcessStep(Type is Group)

no attributes
- Browse(Type is Group)
  attributes
  
  processDescription: Browse processing is performed for each granule SIPS produces. The browse utility reads data from the granule and produces browse images as defined in the respective product ATBD. The utility then embeds each browse image into the product within the /Browse group. (Type is String)
  
  identifier: atlas_brw (Type is String)
  
  softwareVersion: Version 3.1.3 (Type is String)
  
  softwareDate: Apr 8 2025 (Type is String)
  
  softwareTitle: Creates ATLAS HDF5 browse files (Type is String)
  
  runTimeParameters: CTL_atlas_l3a_is_021426921.ctl (Type is String)
  
  stepDateTime: 2025-12-19T22:01:57.000000Z (Type is String)
- Metadata(Type is Group)
  attributes
  
  processDescription: Metadata information is processed by the metadata utility for each granule produced by SIPS. During PGE processing, dynamic metadata are written to the product. Additional static information is provided with the metadata template. The metadata utility reads ISO Dataset and Series metadata files and updates the product with static information from within those files. The utility then merges the static and dynamic metadata to creates output ISO19139 Dataset and Series XML files. Finally the utility reads the ISO19139 Dataset and Series XML files into memory and stores the textual representations as attributes attached to the /METADATA group. (Type is String)
  
  identifier: atlas_meta (Type is String)
  
  softwareVersion: Version 5.1.3 (Type is String)
  
  softwareDate: Apr 8 2025 (Type is String)
  
  softwareTitle: Creates ATLAS XML metadata files (Type is String)
  
  runTimeParameters: CTL_atlas_l3a_is_021426921.ctl (Type is String)
  
  stepDateTime: 2025-12-19T22:02:07.000000Z (Type is String)
- PGE(Type is Group)
  attributes
  
  ATBDDate: 12/04/2019 (Type is String)
  
  ATBDTitle: Algorithm Theoretical Basis Document (ATBD) For Land-Ice Along-Track Products Part 2: Land-ice H(t)/ATL11 (Type is String)
  
  ATBDVersion: N/A (Type is String)
  
  documentDate: Feb 2020 (Type is String)
  
  documentation: ATLAS Science Algorithm Software Design Description (SDD) - Volume 9 (atlas_l3a_is) (Type is String)
  
  processDescription: Computes surface heights for each beam, along and across-track slopes calculated for beam pairs. (Type is String)
  
  identifier: atlas_l3a_is (Type is String)
  
  softwareVersion: Version 5.1 (Type is String)
  
  softwareDate: Apr 8 2025 (Type is String)
  
  softwareTitle: ASAS L3A Icesheet PGE (Type is String)
  
  runTimeParameters: CTL_atlas_l3a_is_021426921.ctl (Type is String)
  
  stepDateTime: 2025-12-19T22:01:54.000000Z (Type is String)
- QA(Type is Group)
  attributes
  
  processDescription: QA processing is performed by an external utility on each granule produced by SIPS. The utility reads the granule, performs both generic and product-specific quality-assessment calculations, and writes a text-based quality assessment report. The name and creation data of this report are identified within the QADatasetIdentification metadata (Type is String)
  
  identifier: atl06_qa_util (Type is String)
  
  softwareVersion: Version 5.1 (Type is String)
  
  softwareDate: Apr 8 2025 (Type is String)
  
  softwareTitle: ATL06 QA Utility (Type is String)
  
  runTimeParameters: CTL_atlas_l3a_is_021426921.ctl (Type is String)
  
  stepDateTime: 2025-12-19T22:01:57.000000Z (Type is String)

attributes
- description: Contains data that are common among all beams for the granule. These parameters are constants for a given granule. (Type is String)
- data_rate: These parameters are constant for a given granule. (Type is String)

crossing_time[ /orbit_info/crossing_time= 0..0] (Type is Float64)
- attributes
  - long_name: Ascending Node Crossing Time (Type is String)
  - standard_name: time (Type is String)
  - units: seconds since 2018-01-01 (Type is String)
  - source: POD/PPD (Type is String)
  - contentType: referenceInformation (Type is String)
  - description: The time, in seconds since the ATLAS SDP GPS Epoch, at which the ascending node crosses the equator. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
sc_orient_time[ /orbit_info/sc_orient_time= 0..0] (Type is Float64)
- attributes
  - long_name: Time of Last Spacecraft Orientation Change (Type is String)
  - standard_name: time (Type is String)
  - units: seconds since 2018-01-01 (Type is String)
  - source: POD/PPD (Type is String)
  - contentType: referenceInformation (Type is String)
  - description: The time of the last spacecraft orientation change between forward, backward and transitional flight modes, expressed in seconds since the ATLAS SDP GPS Epoch. ICESat-2 is considered to be flying forward when the weak beams are leading the strong beams; and backward when the strong beams are leading the weak beams. ICESat-2 is considered to be in transition while it is maneuvering between the two orientations. Science quality is potentially degraded while in transition mode. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
cycle_number[ /orbit_info/crossing_time= 0..0] (Type is Int8)
- attributes
  - long_name: Cycle Number (Type is String)
  - units: counts (Type is String)
  - source: POD/PPD (Type is String)
  - valid_min: 0 (Type is Int8)
  - valid_max: 50 (Type is Int8)
  - contentType: referenceInformation (Type is String)
  - description: Tracks the number of 91-day cycles in the mission, beginning with 01. A unique orbit number can be determined by subtracting 1 from the cycle_number, multiplying by 1387 and adding the rgt value. (Type is String)
  - coordinates: crossing_time (Type is String)
rgt[ /orbit_info/crossing_time= 0..0] (Type is Int16)
- attributes
  - long_name: Reference Ground track (Type is String)
  - units: counts (Type is String)
  - source: POD/PPD (Type is String)
  - valid_min: 1 (Type is Int16)
  - valid_max: 1387 (Type is Int16)
  - contentType: referenceInformation (Type is String)
  - description: The reference ground track (RGT) is the track on the earth at which a specified unit vector within the observatory is pointed. Under nominal operating conditions, there will be no data collected along the RGT, as the RGT is spanned by GT2L and GT2R. During slews or off-pointing, it is possible that ground tracks may intersect the RGT. The ICESat-2 mission has 1387 RGTs. (Type is String)
  - coordinates: crossing_time (Type is String)
lan[ /orbit_info/crossing_time= 0..0] (Type is Float64)
- attributes
  - long_name: Ascending Node Longitude (Type is String)
  - units: degrees_east (Type is String)
  - source: POD/PPD (Type is String)
  - valid_min: -180. (Type is Float64)
  - valid_max: 180. (Type is Float64)
  - contentType: referenceInformation (Type is String)
  - description: Longitude at the ascending node crossing. (Type is String)
  - coordinates: crossing_time (Type is String)
bounding_polygon_lat1[ 0..4] (Type is Float64)
- attributes
  - long_name: Polygon1 Latitude (Type is String)
  - units: degrees_north (Type is String)
  - source: geo_poly (Type is String)
  - valid_min: -90. (Type is Float64)
  - valid_max: 90. (Type is Float64)
  - contentType: auxiliaryInformation (Type is String)
  - description: Latitude values for the first out of two possible bounding polygons (Type is String)
orbit_number[ /orbit_info/crossing_time= 0..0] (Type is UInt16)
- attributes
  - long_name: Orbit Number (Type is String)
  - units: 1 (Type is String)
  - source: POD/PPD (Type is String)
  - valid_min: 1 (Type is UInt16)
  - valid_max: 65000 (Type is UInt16)
  - contentType: referenceInformation (Type is String)
  - description: Unique identifying number for each planned ICESat-2 orbit. (Type is String)
  - coordinates: crossing_time (Type is String)
bounding_polygon_lon1[ 0..4] (Type is Float64)
- attributes
  - long_name: Polygon1 Longitude (Type is String)
  - units: degrees_east (Type is String)
  - source: geo_poly (Type is String)
  - valid_min: -180. (Type is Float64)
  - valid_max: 180. (Type is Float64)
  - contentType: auxiliaryInformation (Type is String)
  - description: Longitude values for the first out of two possible bounding polygons (Type is String)
sc_orient[ /orbit_info/sc_orient_time= 0..0] (Type is Int8)
- attributes
  - long_name: Spacecraft Orientation (Type is String)
  - units: 1 (Type is String)
  - source: POD/PPD (Type is String)
  - valid_min: 0 (Type is Int8)
  - valid_max: 2 (Type is Int8)
  - contentType: referenceInformation (Type is String)
  - description: This parameter tracks the spacecraft orientation between forward, backward and transitional flight modes. ICESat-2 is considered to be flying forward when the weak beams are leading the strong beams; and backward when the strong beams are leading the weak beams. ICESat-2 is considered to be in transition while it is maneuvering between the two orientations. Science quality is potentially degraded while in transition mode. (Type is String)
  - coordinates: sc_orient_time (Type is String)
  - flag_meanings: backward forward transition (Type is String)
  - flag_values: 0, 1, 2 (Type is Int8)

attributes
- description: Contains subgroups organized by Ground Track (gt1l, gt1r, gt2l, gt2r, gt3l and gt3r) (Type is String)
- atlas_pce: pce1 (Type is String)
- atlas_beam_type: weak (Type is String)
- groundtrack_id: gt3l (Type is String)
- atmosphere_profile: profile_3 (Type is String)
- atlas_spot_number: 2 (Type is String)
- sc_orientation: Forward (Type is String)

land_ice_segments(Type is Group)
- attributes
  - description: The land_ice_height group contains the primary set of derived ATL06 products. This includes geolocation, height, and standard error and quality measures for each segment. This group is sparse, meaning that parameters are provided only for pairs of segments for which at least one beam has a valid surface-height measurement. (Type is String)
  - data_rate: Data within this group are sparse. Data values are provided only for those ICESat-2 20m segments where at least one beam has a valid land ice height measurement. (Type is String)
Dimensions: [ /gt3l/land_ice_segments/delta_time = 0..187 ]
- latitude[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float64)
  attributes
  
  long_name: Latitude (Type is String)
  
  standard_name: latitude (Type is String)
  
  units: degrees_north (Type is String)
  
  source: ATL06 ATBD - Top Level Fitting Routine (Type is String)
  
  valid_min: -90. (Type is Float64)
  
  valid_max: 90. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Latitude of segment center, WGS84, North=+, (Type is String)
  
  coordinates: delta_time longitude (Type is String)
- delta_time[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float64)
  attributes
  
  long_name: Elapsed GPS seconds (Type is String)
  
  standard_name: time (Type is String)
  
  units: seconds since 2018-01-01 (Type is String)
  
  source: ATL06 ATBD - Top Level Fitting Routine (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
  
  coordinates: latitude longitude (Type is String)
- longitude[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float64)
  attributes
  
  long_name: Longitude (Type is String)
  
  standard_name: longitude (Type is String)
  
  units: degrees_east (Type is String)
  
  source: ATL06 ATBD - Top Level Fitting Routine (Type is String)
  
  valid_min: -180. (Type is Float64)
  
  valid_max: 180. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Longitude of segment center, , WGS84, East=+ (Type is String)
  
  coordinates: delta_time latitude (Type is String)
- sigma_geo_h[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Vertical Geolocation Error (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Segment Geolocation (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Total vertical geolocation error due to PPD and POD, including the effects of horizontal geolocation error on the segment vertical error. (Type is String)
  
  coordinates: delta_time latitude longitude (Type is String)
- h_li[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Land Ice height (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Top Level Fitting Routine (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Standard land-ice segment height determined by land ice algorithm, corrected for first-photon bias, representing the median- based height of the selected PEs (Type is String)
  
  coordinates: delta_time latitude longitude (Type is String)
- atl06_quality_summary[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8)
  attributes
  
  long_name: ATL06_Quality_Summary (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Top Level Fitting Routine (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 1 (Type is Int8)
  
  contentType: qualityInformation (Type is String)
  
  description: The ATL06_quality_summary parameter indicates the best-quality subset of all ATL06 data. A zero in this parameter implies that no data-quality tests have found a problem with the segment, a one implies that some potential problem has been found. Users who select only segments with zero values for this flag can be relatively certain of obtaining high-quality data, but will likely miss a significant fraction of usable data, particularly in cloudy, rough, or low-surface-reflectance conditions. (Type is String)
  
  coordinates: delta_time latitude longitude (Type is String)
  
  flag_meanings: best_quality potential_problem (Type is String)
  
  flag_values: 0, 1 (Type is Int8)
- segment_id[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int32)
  attributes
  
  _FillValue: 0 (Type is Int32)
  
  long_name: Reference Point, m (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Top Level Fitting Routine (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Segment number, counting from the equator. Equal to the segment_id for the second of the two 20m ATL03 segments included in the 40m ATL06 segment (Type is String)
  
  coordinates: delta_time latitude longitude (Type is String)
- h_li_sigma[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Expected RMS segment misfit (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Top Level Fitting Routine (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Propagated error due to sampling error and FPB correction from the land ice algorithm (Type is String)
  
  coordinates: delta_time latitude longitude (Type is String)
- fpb_warning_flag[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8)
  attributes
  
  long_name: fpb_warning_flag (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - FPB Corrections (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 1 (Type is Int8)
  
  contentType: qualityInformation (Type is String)
  
  description: To flag that segments have potentially erroneous FPB corrections, the ATL06 algorithm sets fpb_warning_flag to 1 if full_sat_fract is greater than 0.90 (strong beams) or greater than 0.40 (weak beams) for either of the two ATL03 20 m segments that are used as inputs to each ATL06 40 m segment. Otherwise, fpb_warning_flag is set to 0. (Type is String)
  
  coordinates: latitude longitude delta_time (Type is String)
  
  flag_meanings: best_quality potential_problem (Type is String)
  
  flag_values: 0, 1 (Type is Int8)
- fit_statistics(Type is Group)
  attributes
  
  description: The fit_statistics subgroup contains a variety of parameters that might indicate the quality of the fitted segment data. Data in this group are sparse, with dimensions matching the land_ice_height group. (Type is String)
  
  data_rate: Data within this group are stored at the land_ice_height segment rate. (Type is String)
  h_mean[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Height Mean (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String)
  
  contentType: modelResult (Type is String)
  
  description: Mean surface height, not corrected for first-photon bias or pulse truncation. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  signal_selection_source[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8)
  
  attributes
  
  long_name: Signal Selection Source (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Signal Selection based on ATL03 flags (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 3 (Type is Int8)
  
  contentType: qualityInformation (Type is String)
  
  description: Indicates the last algorithm attempted to select the signal for ATL06 fitting. 0=Signal selection succeeded using ATL03 detected PE; 1=Signal selection failed using ATL03 detected PE but succeeded using all flagged ATL03 PE; 2=Signal selection failed using all flagged ATL03 PE, but succeeded using the backup algorithm; 3=All signal-finding strategies failed. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  flag_meanings: succeeded_using_pe succeeded_using_flagged_pe succeeded_using_backup failed (Type is String)
  
  flag_values: 0, 1, 2, 3 (Type is Int8)
  
  snr[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: SNR (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Iterative Least Squares Fitting Routine (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Signal-to-noise ratio in the final refined window (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  h_robust_sprd[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Robust Spread (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: RDE of misfit between PE heights and the along-track segment fit. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  n_seg_pulses[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  units: counts (Type is String)
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Number potential segment pulses (Type is String)
  
  source: ATL06 ATBD - Top-Level Fitting Routine (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: The number of pulses potentially included in the segment (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  dh_fit_dx_sigma[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Sigma of Along Track Slope (Type is String)
  
  units: meters/meters (Type is String)
  
  source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Propagated error in the along-track segment slope (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  snr_significance[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: SNR Significance (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Top-Level Fitting Routine (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Probability that signal-finding routine would converge to at least the observed SNR for a random-noise input. Small values indicate a small likelihood of a surface-detection blunder. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  h_expected_rms[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Expected RMS misfit (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Iterative ground-window refinement (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Expected RMS misfit between PE heights and along-track segment fit (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  dh_fit_dy[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Across Track Slope (Type is String)
  
  units: meters/meters (Type is String)
  
  source: ATL06 ATBD - Top-Level Fitting Routine (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Across track slope from segment fits to weak and strong beam; the same slope is reported for both laser beams in each pair (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  sigma_h_mean[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Height Error (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Propagated Height Errors (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Propagated height error due to PE-height sampling error for height from the along-track fit, not including geolocation-induced error (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  h_rms_misfit[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: RMS Misfit (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD -Iterative Least-Squares Fitting Routine (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: RMS misfit between PE heights and along- track segment fit (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  signal_selection_source_status[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8)
  
  attributes
  
  long_name: Signal Selection Source Status (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Signal Selection based on ATL03 flags (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 4 (Type is Int8)
  
  contentType: qualityInformation (Type is String)
  
  description: Indicates the status of the last signal selection algorithm attempted (see signal_selection_source). The definition of flag is different for each source and are defined in each of the signal_selection_status flags. (See Land Ice ATBD Table 3-2). (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  dh_fit_dx[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Along Track Slope (Type is String)
  
  units: meters/meters (Type is String)
  
  source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Along-track slope from along-track segment fit (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  n_fit_photons[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int32)
  
  attributes
  
  _FillValue: 2147483647 (Type is Int32)
  
  long_name: Number of Photons in Fit (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Number of PEs used in determining h_li, after editing (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  w_surface_window_final[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Surface Window Width (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Top-Level Fitting Routine (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Width of the surface window, top to bottom (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
- ground_track(Type is Group)
  attributes
  
  description: The ground_track group contains parameters describing the GT and RGT for each land ice segment, as well as angular information about the beams. (Type is String)
  
  data_rate: Data within this group are stored at the land_ice_height segment rate. (Type is String)
  sigma_geo_at[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Along Track Geolocation Error (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Segment Geolocation (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Along-track component of the geolocation error. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  ref_azimuth[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Azimuth (Type is String)
  
  units: degrees (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: The direction, eastwards from north, of the laser beam vector as seen by an observer at the laser ground spot viewing toward the spacecraft (i.e., the vector from the ground to the spacecraft). (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  sigma_geo_r[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Radial Orbit Error (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Segment Geolocation (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Radial orbit component of the geolocation error. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  seg_azimuth[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Segment Azimuth (Type is String)
  
  units: degrees (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Azimuth of the pair-track, east of local north. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  sigma_geo_xt[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Across Track Geolocation Error (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Segment Geolocation (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Across-track component of the geolocation error. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  ref_coelv[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Co-elevation (Type is String)
  
  units: degrees (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Coelevation (CE) is direction from vertical of the laser beam as seen by an observer located at the laser ground spot. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  x_atc[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float64)
  
  attributes
  
  _FillValue: 1.7976931348623157e+308 (Type is Float64)
  
  long_name: X Along Track (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Local Coordinate Systems (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: The along-track x-coordinate of the segment, measured parallel to the RGT, measured from the ascending node of the equatorial crossing of a given RGT. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  y_atc[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Y Along Track (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Local Coordinate Systems (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Along-track y coordinate of the segment, relative to the RGT, measured along the perpendicular to the RGT, positive to the right of the RGT. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
- dem(Type is Group)
  attributes
  
  description: Contains reference DEM and geoid heights. (Type is String)
  
  data_rate: Data within this group are stored at the land_ice segment rate. (Type is String)
  dem_flag[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8)
  
  attributes
  
  long_name: DEM Source Flag (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL03 (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 4 (Type is Int8)
  
  contentType: referenceInformation (Type is String)
  
  description: Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=Global, 3=MSS, 4=Antarctic. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  flag_meanings: none arctic global mss antarctic (Type is String)
  
  flag_values: 0, 1, 2, 3, 4 (Type is Int8)
  
  geoid_free2mean[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Geoid Free-to-Mean conversion (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: modelResult (Type is String)
  
  description: Additive value to convert geoid heights from the tide-free system to the mean-tide system. (Add to geoid to get the geoid heights in the mean-tide system.) (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  dem_h[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: DEM Height (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Height of the DEM, interpolated by cubic-spline interpolation in the DEM coordinate system to the PE location. (Best available DEM value in priority of Arctic/Antarctic/Global/MSS) (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  geoid_h[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Geoid Height (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Geoid height above WGS-84 reference ellipsoid (range -107 to 86m) in the tide-free system. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
- geophysical(Type is Group)
  attributes
  
  description: The sun_and_clouds group contains parameters related to solar background and parameters indicative of the presence or absence of clouds. (Type is String)
  
  data_rate: Data within this group are stored at the land_ice_height segment rate. (Type is String)
  msw_flag[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8)
  
  attributes
  
  _FillValue: 127 (Type is Int8)
  
  long_name: Multiple Scattering Warning Flag (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL09 (Type is String)
  
  valid_min: -1 (Type is Int8)
  
  valid_max: 5 (Type is Int8)
  
  contentType: referenceInformation (Type is String)
  
  description: Multiple Scattering warning flag. The multiple scattering warning flag (ATL09 parameter msw_flag) has values from -1 to 5 where zero means no multiple scattering and 5 the greatest. If no layers were detected, then msw_flag = 0. If blowing snow is detected and its estimated optical depth is greater than or equal to 0.5, then msw_flag = 5. If the blowing snow optical depth is less than 0.5, then msw_flag = 4. If no blowing snow is detected but there are cloud or aerosol layers detected, the msw_flag assumes values of 1 to 3 based on the height of the bottom of the lowest layer: < 1 km, msw_flag = 3; 1-3 km, msw_flag = 2; > 3km, msw_flag = 1. A value of -1 indicates that the signal to noise of the data was too low to reliably ascertain the presence of cloud or blowing snow. We expect values of -1 to occur only during daylight. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  flag_meanings: cannot_determine no_layers layer_gt_3km layer_between_1_and_3_km layer_lt_1km blow_snow_od_lt_0.5 blow_snow_od_gt_0.5 (Type is String)
  
  flag_values: -1, 0, 1, 2, 3, 4, 5 (Type is Int8)
  
  layer_flag[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8)
  
  attributes
  
  units: 1 (Type is String)
  
  source: ATL09 (Type is String)
  
  _FillValue: 127 (Type is Int8)
  
  long_name: Consolidated cloud flag (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 1 (Type is Int8)
  
  contentType: referenceInformation (Type is String)
  
  description: This flag is a combination of multiple flags (cloud_flag_atm, cloud_flag_asr, and bsnow_con) and takes daytime/nighttime into consideration. A value of 1 means clouds or blowing snow are likely present. A value of 0 indicates the likely absence of clouds or blowing snow. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  flag_meanings: likely_clear likely_cloudy (Type is String)
  
  flag_values: 0, 1 (Type is Int8)
  
  bsnow_conf[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8)
  
  attributes
  
  _FillValue: 127 (Type is Int8)
  
  long_name: Blowing Snow confidence (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL09 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Confidence flag for presence of blowing snow (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  bsnow_h[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Blowing Snow Layer Top Height (Type is String)
  
  units: meters (Type is String)
  
  source: ATL09 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Blowing snow layer top height (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  tide_ocean[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Ocean Tide (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Ocean Tides including diurnal and semi-diurnal (harmonic analysis), and longer period tides (dynamic and self-consistent equilibrium). (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  tide_earth[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Earth Tide (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Solid earth tides in the tide-free system. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  solar_azimuth[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: solar azimuth (Type is String)
  
  units: degrees_east (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  r_eff[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Effective uncorrected reflectance (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Top-Level Fitting Routine (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Effective reflectance, uncorrected for atmospheric effects. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  dac[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Dynamic Atmosphere Correction (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  tide_load[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Load Tide (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Load Tide - Local displacement due to Ocean Loading (-6 to 0 cm). (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  tide_earth_free2mean[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Earth Tide Free-to-Mean conversion (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Additive value to convert solid earth tide from the tide-free system to the mean tide system. (Add to tide_earth to get solid earth tides in the mean-tide system.) (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  bsnow_od[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Blowing snow OD (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL09 (Type is String)
  
  contentType: modelResult (Type is String)
  
  description: Optical thickness of blowing snow layer. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  tide_equilibrium[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Equilibrium Tide (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Long period equilibrium tide self-consistent with the ocean tide model (+-0.04m). (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  cloud_flg_atm[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8)
  
  attributes
  
  _FillValue: 127 (Type is Int8)
  
  long_name: Cloud Flag ATM (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL09 (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 10 (Type is Int8)
  
  contentType: referenceInformation (Type is String)
  
  description: Number of layers found from the backscatter profile using the DDA layer finder. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  solar_elevation[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: solar elevation (Type is String)
  
  units: degrees (Type is String)
  
  source: ATL03 (Type is String)
  
  valid_min: -90. (Type is Float32)
  
  valid_max: 90. (Type is Float32)
  
  contentType: referenceInformation (Type is String)
  
  description: Solar Angle above or below the plane tangent to the ellipsoid surface at the laser spot. Positive values mean the sun is above the horizon, while negative values mean it is below the horizon. The effect of atmospheric refraction is not included. This is a low-precision value, with approximately TBD degree accuracy. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  tide_pole[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Solid Earth Pole Tide (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Solid Earth Pole Tide -Rotational deformation due to polar motion (-1.5 to 1.5 cm). (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  e_bckgrd[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Expected background count rate (Type is String)
  
  units: hz (Type is String)
  
  source: ATL06 ATBD - Background PE Rate (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Expected background count rate based on sun angle, surface slope, for unit surface reflectance (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  cloud_flg_asr[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8)
  
  attributes
  
  _FillValue: 127 (Type is Int8)
  
  long_name: Cloud Flag ASR (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL09 (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 5 (Type is Int8)
  
  contentType: referenceInformation (Type is String)
  
  description: Cloud flag (probability) from apparent surface reflectance. 0=clear with high confidence; 1=clear with medium confidence; 2=clear with low confidence; 3=cloudy with low confidence; 4=cloudy with medium confidence; 5=cloudy with high confidence (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  flag_meanings: clear_with_high_confidence clear_with_medium_confidence clear_with_low_confidence cloudy_with_low_confidence cloudy_with_medium_confidence cloudy_with_high_confidence (Type is String)
  
  flag_values: 0, 1, 2, 3, 4, 5 (Type is Int8)
  
  bckgrd[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Background count rate (Type is String)
  
  units: hz (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Background count rate, derived from the ATL03 50-shot-average, interpolated to the segment center. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  neutat_delay_total[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Total Neutral Atmospheric Delay (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Total neutral atmosphere delay correction (wet+dry). (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
- bias_correction(Type is Group)
  attributes
  
  description: The bias_correction group contains information about the estimated first-photon bias, and the transmit-pulse-shape bias. (Type is String)
  
  data_rate: Data within this group are stored at the land_ice segment rate. (Type is String)
  fpb_mean_corr_sigma[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  units: meters (Type is String)
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: fpb mean corr sigma (Type is String)
  
  source: ATL06 ATBD - First-Photon Bias Correction (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Estimated error in fpb_mean_corr (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  fpb_med_corr_sigma[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: fpb median corr sigma (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - First-Photon Bias Correction (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Estimated error in fpb_med_corr (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  fpb_mean_corr[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: first photon bias mean correction (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - First-Photon Bias Correction (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Estimated first-photon bias (fpb) correction to mean segment height (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  med_r_fit[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: mean median residual (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Top-Level Fitting Routine (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Difference between uncorrected mean and median of linear fit residuals (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  fpb_med_corr[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: fpb median corr (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - First-Photon Bias Correction (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: First-photon-bias correction giving the difference between the mean segment height and the corrected median height (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  tx_mean_corr[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: tx shape mean correction (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Transmit-pulse shape correction (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Estimate of the difference between the mean of the full-waveform transmit-pulse and the mean of a broadened, truncated waveform consistent with the received pulse (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  fpb_n_corr[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: fpb number photons corr (Type is String)
  
  units: counts (Type is String)
  
  source: ATL06 ATBD - First-Photon Bias Correction (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Estimated window photon count after first-photon-bias correction (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  tx_med_corr[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: tx shape median correction (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Transmit-pulse shape correction (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Estimate of the difference between the median of the full-waveform transmit-pulse mean and the median of a broadened, truncated waveform consistent with the received pulse (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
residual_histogram(Type is Group)
- attributes
  - data_rate: Data within this group are stored at the 200-meter along-track rate. (Type is String)
  - description: This group contains histograms of the residuals between PE heights and the least-squares fit segment heights, at 200-meter along-track resolution. (Type is String)
Dimensions: [ /gt3l/residual_histogram/delta_time = 0..15 ] [ /gt3l/residual_histogram/bin_top_h = 0..747 ] [ /gt3l/residual_histogram/ds_segment_id = 0..9 ]
- ds_segment_id[ /gt3l/residual_histogram/ds_segment_id= 0..9] (Type is Int8)
  attributes
  
  long_name: Segment ID Index (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  valid_min: 1 (Type is Int8)
  
  valid_max: 10 (Type is Int8)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Relative index of each segment_id used in the derivation of the histogram. (Type is String)
- lat_mean[ /gt3l/residual_histogram/delta_time= 0..15] (Type is Float64)
  attributes
  
  long_name: Latitude Mean (Type is String)
  
  standard_name: latitude (Type is String)
  
  units: degrees_north (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  valid_min: -90. (Type is Float64)
  
  valid_max: 90. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean latitude of the segments included in the histogram (Type is String)
  
  coordinates: delta_time lon_mean (Type is String)
- lon_mean[ /gt3l/residual_histogram/delta_time= 0..15] (Type is Float64)
  attributes
  
  long_name: Longitude Mean (Type is String)
  
  standard_name: longitude (Type is String)
  
  units: degrees_east (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  valid_min: -180. (Type is Float64)
  
  valid_max: 180. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean longitude of the segments included in the histogram (Type is String)
  
  coordinates: delta_time lat_mean (Type is String)
- delta_time[ /gt3l/residual_histogram/delta_time= 0..15] (Type is Float64)
  attributes
  
  long_name: Elapsed GPS seconds (Type is String)
  
  standard_name: time (Type is String)
  
  units: seconds since 2018-01-01 (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
  
  coordinates: lat_mean lon_mean (Type is String)
- bin_top_h[ /gt3l/residual_histogram/bin_top_h= 0..747] (Type is Float32)
  attributes
  
  long_name: Bin Top Height (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Height of the top of each histogram bin, listed in increasing order. The bottom of each bin is equal to the top of the next- lowest bin. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- count[ /gt3l/residual_histogram/delta_time= 0..15] [ /gt3l/residual_histogram/bin_top_h= 0..747] (Type is Int32)
  attributes
  
  _FillValue: 2147483647 (Type is Int32)
  
  long_name: Bin Counts (Type is String)
  
  units: counts (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Residual count falling with each histogram bin. The top height of each histogram bin may be found in the bin_top_h dataset. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- pulse_count[ /gt3l/residual_histogram/delta_time= 0..15] (Type is Float32)
  attributes
  
  long_name: Number of Histogram Segment Pulses (Type is String)
  
  units: counts (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Number of pulses potentially included in the histogram (pulses are counted if they are in the central 20 m of each segment, even if no PE from the pulse are selected). (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- x_atc_mean[ /gt3l/residual_histogram/delta_time= 0..15] (Type is Float64)
  attributes
  
  long_name: Along Track Coordinate Mean (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean along-track coordinate of the segments included in the histogram. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- segment_id_list[ /gt3l/residual_histogram/delta_time= 0..15] [ /gt3l/residual_histogram/ds_segment_id= 0..9] (Type is Int32)
  attributes
  
  long_name: Segment ID List (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Segments ids included in each column of the histogram (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
  
  _FillValue: 2147483647 (Type is Int32)
- bckgrd_per_m[ /gt3l/residual_histogram/delta_time= 0..15] (Type is Float32)
  attributes
  
  long_name: Expected background PEs (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Number of background PE expected for each vertical meter of the histogram based on the observed background rate (bckgrd). (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
segment_quality(Type is Group)
- attributes
  - data_rate: Data within this group are stored at the ICESat-2 20m segment rate. (Type is String)
  - description: The segment_quality group contains a dense record (i.e. for every possible segment in the granule) of the success or failure of the surface-finding strategies, and gives the locations of the reference points on the RPTs. For segments with adequate data quality (i.e. with more than 10 PE) it also contains offsets into the data structures for the other groups that allow each segment to be efficiently located within the file. (Type is String)
Dimensions: [ /gt3l/segment_quality/delta_time = 0..201 ]
- reference_pt_lat[ /gt3l/segment_quality/delta_time= 0..201] (Type is Float64)
  attributes
  
  long_name: Latitude (Type is String)
  
  units: degrees_north (Type is String)
  
  source: ATL06 ATBD - segment_quality group (Type is String)
  
  valid_min: -90. (Type is Float64)
  
  valid_max: 90. (Type is Float64)
  
  contentType: referenceInformation (Type is String)
  
  description: Latitude of the reference segment location on the RPT (Type is String)
  
  coordinates: delta_time reference_pt_lon (Type is String)
  
  standard_name: latitude (Type is String)
- reference_pt_lon[ /gt3l/segment_quality/delta_time= 0..201] (Type is Float64)
  attributes
  
  long_name: Longitude (Type is String)
  
  units: degrees_east (Type is String)
  
  source: ATL06 ATBD - segment_quality group (Type is String)
  
  valid_min: -180. (Type is Float64)
  
  valid_max: 180. (Type is Float64)
  
  contentType: referenceInformation (Type is String)
  
  description: Longitude of the reference segment location on the RPT (Type is String)
  
  coordinates: delta_time reference_pt_lat (Type is String)
  
  standard_name: longitude (Type is String)
- delta_time[ /gt3l/segment_quality/delta_time= 0..201] (Type is Float64)
  attributes
  
  long_name: Elapsed GPS seconds (Type is String)
  
  standard_name: time (Type is String)
  
  units: seconds since 2018-01-01 (Type is String)
  
  source: ATL06 ATBD - segment_quality group (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
  
  coordinates: reference_pt_lat reference_pt_lon (Type is String)
- record_number[ /gt3l/segment_quality/delta_time= 0..201] (Type is Int32)
  attributes
  
  long_name: Land Ice Height Index (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - segment_quality group (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: For those segments that have adequate signal strength, this parameter gives the record for the pair within the other groups in the granule. (Type is String)
  
  coordinates: delta_time reference_pt_lat reference_pt_lon (Type is String)
- signal_selection_source[ /gt3l/segment_quality/delta_time= 0..201] (Type is Int8)
  attributes
  
  long_name: Signal Selection Source (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Signal selection base on ATL03 flags (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 3 (Type is Int8)
  
  contentType: qualityInformation (Type is String)
  
  description: Indicates the last algorithm attempted to select the signal for ATL06 fitting. 0=Signal selection succeeded using ATL03 detected PE; 1=Signal selection failed using ATL03 detected PE but succeeded using all flagged ATL03 PE; 3=All signal-finding strategies failed. (Type is String)
  
  coordinates: delta_time reference_pt_lat reference_pt_lon (Type is String)
  
  flag_meanings: succeeded_using_pe succeeded_using_flagged_pe failed (Type is String)
  
  flag_values: 0, 1, 3 (Type is Int8)
- segment_id[ /gt3l/segment_quality/delta_time= 0..201] (Type is Int32)
  attributes
  
  long_name: Reference Point, m (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - segment_quality group (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Segment number corresponding to the second of two ATL03 segments in the ATL06 segment, counted from the RGT equator crossing (Type is String)
  
  coordinates: delta_time reference_pt_lat reference_pt_lon (Type is String)
- signal_selection_status(Type is Group)
  attributes
  
  description: The signal selection status subgroup contains the success or failure for each surface-finding strategies (Type is String)
  
  data_rate: Data within this group are stored at the ICESat-2 20m segment rate. (Type is String)
  signal_selection_status_all[ /gt3l/segment_quality/delta_time= 0..201] (Type is Int8)
  
  attributes
  
  units: 1 (Type is String)
  
  long_name: Signal Selection Status Flag (Type is String)
  
  source: ATL06 ATBD - Signal selection base on ATL03 flags (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 3 (Type is Int8)
  
  contentType: qualityInformation (Type is String)
  
  description: Indicates confidence of the signal-selection algorithm using all ATL03-flagged PEs. 0=Signal selection succeeded using all ATL03-flagged PEs (or algorithm not attempted); 1=Signal selection using all ATL03-flagged PEs failed the 20-meter-spread test; 2=Signal selection using all ATL03-flagged PEs failed the 10-photon-count test; 3=Signal selection using all ATL03-flagged PEs failed both tests (Type is String)
  
  coordinates: ../delta_time ../reference_pt_lat ../reference_pt_lon (Type is String)
  
  flag_meanings: succeeded failed_20 failed_10 failed_both (Type is String)
  
  flag_values: 0, 1, 2, 3 (Type is Int8)
  
  signal_selection_status_confident[ /gt3l/segment_quality/delta_time= 0..201] (Type is Int8)
  
  attributes
  
  units: 1 (Type is String)
  
  long_name: Signal Selection Confident Flag (Type is String)
  
  source: ATL06 ATBD - Signal selection base on ATL03 flags (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 3 (Type is Int8)
  
  contentType: qualityInformation (Type is String)
  
  description: Indicates confidence of the signal-selection algorithm using low or better PEs. 0=Signal selection succeeded using ATL03 low-or-better confidence PEs; 1=Signal selection using ATL03 low-or-better confidence PEs failed the 20-meter-spread test; 2=Signal selection using ATL03 low-or-better confidence PEs failed the 10-photon-count test; 3=Signal selection using ATL03 low-or-better confidence PEs failed both tests (Type is String)
  
  coordinates: ../delta_time ../reference_pt_lat ../reference_pt_lon (Type is String)
  
  flag_meanings: succeeded failed_20 failed_10 failed_both (Type is String)
  
  flag_values: 0, 1, 2, 3 (Type is Int8)

attributes
- description: Contains subgroups organized by Ground Track (gt1l, gt1r, gt2l, gt2r, gt3l and gt3r) (Type is String)
- atlas_pce: pce1 (Type is String)
- atlas_beam_type: strong (Type is String)
- groundtrack_id: gt3r (Type is String)
- atmosphere_profile: profile_3 (Type is String)
- atlas_spot_number: 1 (Type is String)
- sc_orientation: Forward (Type is String)

land_ice_segments(Type is Group)
- attributes
  - description: The land_ice_height group contains the primary set of derived ATL06 products. This includes geolocation, height, and standard error and quality measures for each segment. This group is sparse, meaning that parameters are provided only for pairs of segments for which at least one beam has a valid surface-height measurement. (Type is String)
  - data_rate: Data within this group are sparse. Data values are provided only for those ICESat-2 20m segments where at least one beam has a valid land ice height measurement. (Type is String)
Dimensions: [ /gt3r/land_ice_segments/delta_time = 0..187 ]
- latitude[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float64)
  attributes
  
  long_name: Latitude (Type is String)
  
  standard_name: latitude (Type is String)
  
  units: degrees_north (Type is String)
  
  source: ATL06 ATBD - Top Level Fitting Routine (Type is String)
  
  valid_min: -90. (Type is Float64)
  
  valid_max: 90. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Latitude of segment center, WGS84, North=+, (Type is String)
  
  coordinates: delta_time longitude (Type is String)
- delta_time[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float64)
  attributes
  
  long_name: Elapsed GPS seconds (Type is String)
  
  standard_name: time (Type is String)
  
  units: seconds since 2018-01-01 (Type is String)
  
  source: ATL06 ATBD - Top Level Fitting Routine (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
  
  coordinates: latitude longitude (Type is String)
- longitude[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float64)
  attributes
  
  long_name: Longitude (Type is String)
  
  standard_name: longitude (Type is String)
  
  units: degrees_east (Type is String)
  
  source: ATL06 ATBD - Top Level Fitting Routine (Type is String)
  
  valid_min: -180. (Type is Float64)
  
  valid_max: 180. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Longitude of segment center, , WGS84, East=+ (Type is String)
  
  coordinates: delta_time latitude (Type is String)
- sigma_geo_h[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Vertical Geolocation Error (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Segment Geolocation (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Total vertical geolocation error due to PPD and POD, including the effects of horizontal geolocation error on the segment vertical error. (Type is String)
  
  coordinates: delta_time latitude longitude (Type is String)
- h_li[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Land Ice height (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Top Level Fitting Routine (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Standard land-ice segment height determined by land ice algorithm, corrected for first-photon bias, representing the median- based height of the selected PEs (Type is String)
  
  coordinates: delta_time latitude longitude (Type is String)
- atl06_quality_summary[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8)
  attributes
  
  long_name: ATL06_Quality_Summary (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Top Level Fitting Routine (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 1 (Type is Int8)
  
  contentType: qualityInformation (Type is String)
  
  description: The ATL06_quality_summary parameter indicates the best-quality subset of all ATL06 data. A zero in this parameter implies that no data-quality tests have found a problem with the segment, a one implies that some potential problem has been found. Users who select only segments with zero values for this flag can be relatively certain of obtaining high-quality data, but will likely miss a significant fraction of usable data, particularly in cloudy, rough, or low-surface-reflectance conditions. (Type is String)
  
  coordinates: delta_time latitude longitude (Type is String)
  
  flag_meanings: best_quality potential_problem (Type is String)
  
  flag_values: 0, 1 (Type is Int8)
- segment_id[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int32)
  attributes
  
  _FillValue: 0 (Type is Int32)
  
  long_name: Reference Point, m (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Top Level Fitting Routine (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Segment number, counting from the equator. Equal to the segment_id for the second of the two 20m ATL03 segments included in the 40m ATL06 segment (Type is String)
  
  coordinates: delta_time latitude longitude (Type is String)
- h_li_sigma[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Expected RMS segment misfit (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Top Level Fitting Routine (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Propagated error due to sampling error and FPB correction from the land ice algorithm (Type is String)
  
  coordinates: delta_time latitude longitude (Type is String)
- fpb_warning_flag[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8)
  attributes
  
  long_name: fpb_warning_flag (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - FPB Corrections (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 1 (Type is Int8)
  
  contentType: qualityInformation (Type is String)
  
  description: To flag that segments have potentially erroneous FPB corrections, the ATL06 algorithm sets fpb_warning_flag to 1 if full_sat_fract is greater than 0.90 (strong beams) or greater than 0.40 (weak beams) for either of the two ATL03 20 m segments that are used as inputs to each ATL06 40 m segment. Otherwise, fpb_warning_flag is set to 0. (Type is String)
  
  coordinates: latitude longitude delta_time (Type is String)
  
  flag_meanings: best_quality potential_problem (Type is String)
  
  flag_values: 0, 1 (Type is Int8)
- fit_statistics(Type is Group)
  attributes
  
  description: The fit_statistics subgroup contains a variety of parameters that might indicate the quality of the fitted segment data. Data in this group are sparse, with dimensions matching the land_ice_height group. (Type is String)
  
  data_rate: Data within this group are stored at the land_ice_height segment rate. (Type is String)
  h_mean[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Height Mean (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String)
  
  contentType: modelResult (Type is String)
  
  description: Mean surface height, not corrected for first-photon bias or pulse truncation. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  signal_selection_source[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8)
  
  attributes
  
  long_name: Signal Selection Source (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Signal Selection based on ATL03 flags (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 3 (Type is Int8)
  
  contentType: qualityInformation (Type is String)
  
  description: Indicates the last algorithm attempted to select the signal for ATL06 fitting. 0=Signal selection succeeded using ATL03 detected PE; 1=Signal selection failed using ATL03 detected PE but succeeded using all flagged ATL03 PE; 2=Signal selection failed using all flagged ATL03 PE, but succeeded using the backup algorithm; 3=All signal-finding strategies failed. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  flag_meanings: succeeded_using_pe succeeded_using_flagged_pe succeeded_using_backup failed (Type is String)
  
  flag_values: 0, 1, 2, 3 (Type is Int8)
  
  snr[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: SNR (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Iterative Least Squares Fitting Routine (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Signal-to-noise ratio in the final refined window (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  h_robust_sprd[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Robust Spread (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: RDE of misfit between PE heights and the along-track segment fit. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  n_seg_pulses[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  units: counts (Type is String)
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Number potential segment pulses (Type is String)
  
  source: ATL06 ATBD - Top-Level Fitting Routine (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: The number of pulses potentially included in the segment (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  dh_fit_dx_sigma[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Sigma of Along Track Slope (Type is String)
  
  units: meters/meters (Type is String)
  
  source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Propagated error in the along-track segment slope (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  snr_significance[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: SNR Significance (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Top-Level Fitting Routine (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Probability that signal-finding routine would converge to at least the observed SNR for a random-noise input. Small values indicate a small likelihood of a surface-detection blunder. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  h_expected_rms[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Expected RMS misfit (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Iterative ground-window refinement (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Expected RMS misfit between PE heights and along-track segment fit (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  dh_fit_dy[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Across Track Slope (Type is String)
  
  units: meters/meters (Type is String)
  
  source: ATL06 ATBD - Top-Level Fitting Routine (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Across track slope from segment fits to weak and strong beam; the same slope is reported for both laser beams in each pair (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  sigma_h_mean[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Height Error (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Propagated Height Errors (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Propagated height error due to PE-height sampling error for height from the along-track fit, not including geolocation-induced error (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  h_rms_misfit[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: RMS Misfit (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD -Iterative Least-Squares Fitting Routine (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: RMS misfit between PE heights and along- track segment fit (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  signal_selection_source_status[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8)
  
  attributes
  
  long_name: Signal Selection Source Status (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Signal Selection based on ATL03 flags (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 4 (Type is Int8)
  
  contentType: qualityInformation (Type is String)
  
  description: Indicates the status of the last signal selection algorithm attempted (see signal_selection_source). The definition of flag is different for each source and are defined in each of the signal_selection_status flags. (See Land Ice ATBD Table 3-2). (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  dh_fit_dx[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Along Track Slope (Type is String)
  
  units: meters/meters (Type is String)
  
  source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Along-track slope from along-track segment fit (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  n_fit_photons[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int32)
  
  attributes
  
  _FillValue: 2147483647 (Type is Int32)
  
  long_name: Number of Photons in Fit (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Number of PEs used in determining h_li, after editing (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  w_surface_window_final[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Surface Window Width (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Top-Level Fitting Routine (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Width of the surface window, top to bottom (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
- ground_track(Type is Group)
  attributes
  
  description: The ground_track group contains parameters describing the GT and RGT for each land ice segment, as well as angular information about the beams. (Type is String)
  
  data_rate: Data within this group are stored at the land_ice_height segment rate. (Type is String)
  sigma_geo_at[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Along Track Geolocation Error (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Segment Geolocation (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Along-track component of the geolocation error. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  ref_coelv[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Co-elevation (Type is String)
  
  units: degrees (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Coelevation (CE) is direction from vertical of the laser beam as seen by an observer located at the laser ground spot. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  sigma_geo_r[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Radial Orbit Error (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Segment Geolocation (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Radial orbit component of the geolocation error. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  seg_azimuth[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Segment Azimuth (Type is String)
  
  units: degrees (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Azimuth of the pair-track, east of local north. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  sigma_geo_xt[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Across Track Geolocation Error (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Segment Geolocation (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Across-track component of the geolocation error. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  ref_azimuth[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Azimuth (Type is String)
  
  units: degrees (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: The direction, eastwards from north, of the laser beam vector as seen by an observer at the laser ground spot viewing toward the spacecraft (i.e., the vector from the ground to the spacecraft). (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  x_atc[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float64)
  
  attributes
  
  _FillValue: 1.7976931348623157e+308 (Type is Float64)
  
  long_name: X Along Track (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Local Coordinate Systems (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: The along-track x-coordinate of the segment, measured parallel to the RGT, measured from the ascending node of the equatorial crossing of a given RGT. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  y_atc[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Y Along Track (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Local Coordinate Systems (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Along-track y coordinate of the segment, relative to the RGT, measured along the perpendicular to the RGT, positive to the right of the RGT. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
- dem(Type is Group)
  attributes
  
  description: Contains reference DEM and geoid heights. (Type is String)
  
  data_rate: Data within this group are stored at the land_ice segment rate. (Type is String)
  dem_flag[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8)
  
  attributes
  
  long_name: DEM Source Flag (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL03 (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 4 (Type is Int8)
  
  contentType: referenceInformation (Type is String)
  
  description: Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=Global, 3=MSS, 4=Antarctic. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  flag_meanings: none arctic global mss antarctic (Type is String)
  
  flag_values: 0, 1, 2, 3, 4 (Type is Int8)
  
  geoid_free2mean[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Geoid Free-to-Mean conversion (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: modelResult (Type is String)
  
  description: Additive value to convert geoid heights from the tide-free system to the mean-tide system. (Add to geoid to get the geoid heights in the mean-tide system.) (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  dem_h[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: DEM Height (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Height of the DEM, interpolated by cubic-spline interpolation in the DEM coordinate system to the PE location. (Best available DEM value in priority of Arctic/Antarctic/Global/MSS) (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  geoid_h[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Geoid Height (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Geoid height above WGS-84 reference ellipsoid (range -107 to 86m) in the tide-free system. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
- geophysical(Type is Group)
  attributes
  
  description: The sun_and_clouds group contains parameters related to solar background and parameters indicative of the presence or absence of clouds. (Type is String)
  
  data_rate: Data within this group are stored at the land_ice_height segment rate. (Type is String)
  msw_flag[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8)
  
  attributes
  
  _FillValue: 127 (Type is Int8)
  
  long_name: Multiple Scattering Warning Flag (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL09 (Type is String)
  
  valid_min: -1 (Type is Int8)
  
  valid_max: 5 (Type is Int8)
  
  contentType: referenceInformation (Type is String)
  
  description: Multiple Scattering warning flag. The multiple scattering warning flag (ATL09 parameter msw_flag) has values from -1 to 5 where zero means no multiple scattering and 5 the greatest. If no layers were detected, then msw_flag = 0. If blowing snow is detected and its estimated optical depth is greater than or equal to 0.5, then msw_flag = 5. If the blowing snow optical depth is less than 0.5, then msw_flag = 4. If no blowing snow is detected but there are cloud or aerosol layers detected, the msw_flag assumes values of 1 to 3 based on the height of the bottom of the lowest layer: < 1 km, msw_flag = 3; 1-3 km, msw_flag = 2; > 3km, msw_flag = 1. A value of -1 indicates that the signal to noise of the data was too low to reliably ascertain the presence of cloud or blowing snow. We expect values of -1 to occur only during daylight. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  flag_meanings: cannot_determine no_layers layer_gt_3km layer_between_1_and_3_km layer_lt_1km blow_snow_od_lt_0.5 blow_snow_od_gt_0.5 (Type is String)
  
  flag_values: -1, 0, 1, 2, 3, 4, 5 (Type is Int8)
  
  layer_flag[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8)
  
  attributes
  
  units: 1 (Type is String)
  
  source: ATL09 (Type is String)
  
  _FillValue: 127 (Type is Int8)
  
  long_name: Consolidated cloud flag (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 1 (Type is Int8)
  
  contentType: referenceInformation (Type is String)
  
  description: This flag is a combination of multiple flags (cloud_flag_atm, cloud_flag_asr, and bsnow_con) and takes daytime/nighttime into consideration. A value of 1 means clouds or blowing snow are likely present. A value of 0 indicates the likely absence of clouds or blowing snow. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  flag_meanings: likely_clear likely_cloudy (Type is String)
  
  flag_values: 0, 1 (Type is Int8)
  
  bsnow_conf[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8)
  
  attributes
  
  _FillValue: 127 (Type is Int8)
  
  long_name: Blowing Snow confidence (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL09 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Confidence flag for presence of blowing snow (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  bsnow_h[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Blowing Snow Layer Top Height (Type is String)
  
  units: meters (Type is String)
  
  source: ATL09 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Blowing snow layer top height (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  tide_ocean[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Ocean Tide (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Ocean Tides including diurnal and semi-diurnal (harmonic analysis), and longer period tides (dynamic and self-consistent equilibrium). (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  tide_earth[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Earth Tide (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Solid earth tides in the tide-free system. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  solar_azimuth[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: solar azimuth (Type is String)
  
  units: degrees_east (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  r_eff[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Effective uncorrected reflectance (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Top-Level Fitting Routine (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Effective reflectance, uncorrected for atmospheric effects. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  dac[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Dynamic Atmosphere Correction (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  tide_load[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Load Tide (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Load Tide - Local displacement due to Ocean Loading (-6 to 0 cm). (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  tide_earth_free2mean[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Earth Tide Free-to-Mean conversion (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Additive value to convert solid earth tide from the tide-free system to the mean tide system. (Add to tide_earth to get solid earth tides in the mean-tide system.) (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  bsnow_od[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Blowing snow OD (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL09 (Type is String)
  
  contentType: modelResult (Type is String)
  
  description: Optical thickness of blowing snow layer. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  tide_equilibrium[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Equilibrium Tide (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Long period equilibrium tide self-consistent with the ocean tide model (+-0.04m). (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  cloud_flg_atm[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8)
  
  attributes
  
  _FillValue: 127 (Type is Int8)
  
  long_name: Cloud Flag ATM (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL09 (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 10 (Type is Int8)
  
  contentType: referenceInformation (Type is String)
  
  description: Number of layers found from the backscatter profile using the DDA layer finder. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  solar_elevation[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: solar elevation (Type is String)
  
  units: degrees (Type is String)
  
  source: ATL03 (Type is String)
  
  valid_min: -90. (Type is Float32)
  
  valid_max: 90. (Type is Float32)
  
  contentType: referenceInformation (Type is String)
  
  description: Solar Angle above or below the plane tangent to the ellipsoid surface at the laser spot. Positive values mean the sun is above the horizon, while negative values mean it is below the horizon. The effect of atmospheric refraction is not included. This is a low-precision value, with approximately TBD degree accuracy. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  tide_pole[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Solid Earth Pole Tide (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Solid Earth Pole Tide -Rotational deformation due to polar motion (-1.5 to 1.5 cm). (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  e_bckgrd[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Expected background count rate (Type is String)
  
  units: hz (Type is String)
  
  source: ATL06 ATBD - Background PE Rate (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Expected background count rate based on sun angle, surface slope, for unit surface reflectance (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  cloud_flg_asr[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8)
  
  attributes
  
  _FillValue: 127 (Type is Int8)
  
  long_name: Cloud Flag ASR (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL09 (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 5 (Type is Int8)
  
  contentType: referenceInformation (Type is String)
  
  description: Cloud flag (probability) from apparent surface reflectance. 0=clear with high confidence; 1=clear with medium confidence; 2=clear with low confidence; 3=cloudy with low confidence; 4=cloudy with medium confidence; 5=cloudy with high confidence (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  flag_meanings: clear_with_high_confidence clear_with_medium_confidence clear_with_low_confidence cloudy_with_low_confidence cloudy_with_medium_confidence cloudy_with_high_confidence (Type is String)
  
  flag_values: 0, 1, 2, 3, 4, 5 (Type is Int8)
  
  bckgrd[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Background count rate (Type is String)
  
  units: hz (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Background count rate, derived from the ATL03 50-shot-average, interpolated to the segment center. (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  neutat_delay_total[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: Total Neutral Atmospheric Delay (Type is String)
  
  units: meters (Type is String)
  
  source: ATL03 (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Total neutral atmosphere delay correction (wet+dry). (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
- bias_correction(Type is Group)
  attributes
  
  description: The bias_correction group contains information about the estimated first-photon bias, and the transmit-pulse-shape bias. (Type is String)
  
  data_rate: Data within this group are stored at the land_ice segment rate. (Type is String)
  fpb_mean_corr_sigma[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  units: meters (Type is String)
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: fpb mean corr sigma (Type is String)
  
  source: ATL06 ATBD - First-Photon Bias Correction (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Estimated error in fpb_mean_corr (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  fpb_med_corr_sigma[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: fpb median corr sigma (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - First-Photon Bias Correction (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Estimated error in fpb_med_corr (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  fpb_mean_corr[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: first photon bias mean correction (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - First-Photon Bias Correction (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Estimated first-photon bias (fpb) correction to mean segment height (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  med_r_fit[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: mean median residual (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Top-Level Fitting Routine (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Difference between uncorrected mean and median of linear fit residuals (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  fpb_med_corr[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: fpb median corr (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - First-Photon Bias Correction (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: First-photon-bias correction giving the difference between the mean segment height and the corrected median height (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  tx_mean_corr[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: tx shape mean correction (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Transmit-pulse shape correction (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Estimate of the difference between the mean of the full-waveform transmit-pulse and the mean of a broadened, truncated waveform consistent with the received pulse (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  fpb_n_corr[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: fpb number photons corr (Type is String)
  
  units: counts (Type is String)
  
  source: ATL06 ATBD - First-Photon Bias Correction (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Estimated window photon count after first-photon-bias correction (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
  
  tx_med_corr[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32)
  
  attributes
  
  _FillValue: 3.402823466e+38 (Type is Float32)
  
  long_name: tx shape median correction (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Transmit-pulse shape correction (Type is String)
  
  contentType: qualityInformation (Type is String)
  
  description: Estimate of the difference between the median of the full-waveform transmit-pulse mean and the median of a broadened, truncated waveform consistent with the received pulse (Type is String)
  
  coordinates: ../delta_time ../latitude ../longitude (Type is String)
residual_histogram(Type is Group)
- attributes
  - data_rate: Data within this group are stored at the 200-meter along-track rate. (Type is String)
  - description: This group contains histograms of the residuals between PE heights and the least-squares fit segment heights, at 200-meter along-track resolution. (Type is String)
Dimensions: [ /gt3r/residual_histogram/delta_time = 0..21 ] [ /gt3r/residual_histogram/bin_top_h = 0..747 ] [ /gt3r/residual_histogram/ds_segment_id = 0..9 ]
- ds_segment_id[ /gt3r/residual_histogram/ds_segment_id= 0..9] (Type is Int8)
  attributes
  
  long_name: Segment ID Index (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  valid_min: 1 (Type is Int8)
  
  valid_max: 10 (Type is Int8)
  
  contentType: auxiliaryInformation (Type is String)
  
  description: Relative index of each segment_id used in the derivation of the histogram. (Type is String)
- lat_mean[ /gt3r/residual_histogram/delta_time= 0..21] (Type is Float64)
  attributes
  
  long_name: Latitude Mean (Type is String)
  
  standard_name: latitude (Type is String)
  
  units: degrees_north (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  valid_min: -90. (Type is Float64)
  
  valid_max: 90. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean latitude of the segments included in the histogram (Type is String)
  
  coordinates: delta_time lon_mean (Type is String)
- lon_mean[ /gt3r/residual_histogram/delta_time= 0..21] (Type is Float64)
  attributes
  
  long_name: Longitude Mean (Type is String)
  
  standard_name: longitude (Type is String)
  
  units: degrees_east (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  valid_min: -180. (Type is Float64)
  
  valid_max: 180. (Type is Float64)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean longitude of the segments included in the histogram (Type is String)
  
  coordinates: delta_time lat_mean (Type is String)
- delta_time[ /gt3r/residual_histogram/delta_time= 0..21] (Type is Float64)
  attributes
  
  long_name: Elapsed GPS seconds (Type is String)
  
  standard_name: time (Type is String)
  
  units: seconds since 2018-01-01 (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
  
  coordinates: lat_mean lon_mean (Type is String)
- bin_top_h[ /gt3r/residual_histogram/bin_top_h= 0..747] (Type is Float32)
  attributes
  
  long_name: Bin Top Height (Type is String)
  
  units: meters (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Height of the top of each histogram bin, listed in increasing order. The bottom of each bin is equal to the top of the next- lowest bin. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- count[ /gt3r/residual_histogram/delta_time= 0..21] [ /gt3r/residual_histogram/bin_top_h= 0..747] (Type is Int32)
  attributes
  
  _FillValue: 2147483647 (Type is Int32)
  
  long_name: Bin Counts (Type is String)
  
  units: counts (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Residual count falling with each histogram bin. The top height of each histogram bin may be found in the bin_top_h dataset. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- pulse_count[ /gt3r/residual_histogram/delta_time= 0..21] (Type is Float32)
  attributes
  
  long_name: Number of Histogram Segment Pulses (Type is String)
  
  units: counts (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Number of pulses potentially included in the histogram (pulses are counted if they are in the central 20 m of each segment, even if no PE from the pulse are selected). (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- x_atc_mean[ /gt3r/residual_histogram/delta_time= 0..21] (Type is Float64)
  attributes
  
  long_name: Along Track Coordinate Mean (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Mean along-track coordinate of the segments included in the histogram. (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
- segment_id_list[ /gt3r/residual_histogram/delta_time= 0..21] [ /gt3r/residual_histogram/ds_segment_id= 0..9] (Type is Int32)
  attributes
  
  long_name: Segment ID List (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Segments ids included in each column of the histogram (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
  
  _FillValue: 2147483647 (Type is Int32)
- bckgrd_per_m[ /gt3r/residual_histogram/delta_time= 0..21] (Type is Float32)
  attributes
  
  long_name: Expected background PEs (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Residual_histogram calculation (Type is String)
  
  contentType: physicalMeasurement (Type is String)
  
  description: Number of background PE expected for each vertical meter of the histogram based on the observed background rate (bckgrd). (Type is String)
  
  coordinates: delta_time lat_mean lon_mean (Type is String)
segment_quality(Type is Group)
- attributes
  - data_rate: Data within this group are stored at the ICESat-2 20m segment rate. (Type is String)
  - description: The segment_quality group contains a dense record (i.e. for every possible segment in the granule) of the success or failure of the surface-finding strategies, and gives the locations of the reference points on the RPTs. For segments with adequate data quality (i.e. with more than 10 PE) it also contains offsets into the data structures for the other groups that allow each segment to be efficiently located within the file. (Type is String)
Dimensions: [ /gt3r/segment_quality/delta_time = 0..201 ]
- reference_pt_lat[ /gt3r/segment_quality/delta_time= 0..201] (Type is Float64)
  attributes
  
  long_name: Latitude (Type is String)
  
  units: degrees_north (Type is String)
  
  source: ATL06 ATBD - segment_quality group (Type is String)
  
  valid_min: -90. (Type is Float64)
  
  valid_max: 90. (Type is Float64)
  
  contentType: referenceInformation (Type is String)
  
  description: Latitude of the reference segment location on the RPT (Type is String)
  
  coordinates: delta_time reference_pt_lon (Type is String)
  
  standard_name: latitude (Type is String)
- reference_pt_lon[ /gt3r/segment_quality/delta_time= 0..201] (Type is Float64)
  attributes
  
  long_name: Longitude (Type is String)
  
  units: degrees_east (Type is String)
  
  source: ATL06 ATBD - segment_quality group (Type is String)
  
  valid_min: -180. (Type is Float64)
  
  valid_max: 180. (Type is Float64)
  
  contentType: referenceInformation (Type is String)
  
  description: Longitude of the reference segment location on the RPT (Type is String)
  
  coordinates: delta_time reference_pt_lat (Type is String)
  
  standard_name: longitude (Type is String)
- delta_time[ /gt3r/segment_quality/delta_time= 0..201] (Type is Float64)
  attributes
  
  long_name: Elapsed GPS seconds (Type is String)
  
  standard_name: time (Type is String)
  
  units: seconds since 2018-01-01 (Type is String)
  
  source: ATL06 ATBD - segment_quality group (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String)
  
  coordinates: reference_pt_lat reference_pt_lon (Type is String)
- record_number[ /gt3r/segment_quality/delta_time= 0..201] (Type is Int32)
  attributes
  
  long_name: Land Ice Height Index (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - segment_quality group (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: For those segments that have adequate signal strength, this parameter gives the record for the pair within the other groups in the granule. (Type is String)
  
  coordinates: delta_time reference_pt_lat reference_pt_lon (Type is String)
- signal_selection_source[ /gt3r/segment_quality/delta_time= 0..201] (Type is Int8)
  attributes
  
  long_name: Signal Selection Source (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - Signal selection base on ATL03 flags (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 3 (Type is Int8)
  
  contentType: qualityInformation (Type is String)
  
  description: Indicates the last algorithm attempted to select the signal for ATL06 fitting. 0=Signal selection succeeded using ATL03 detected PE; 1=Signal selection failed using ATL03 detected PE but succeeded using all flagged ATL03 PE; 3=All signal-finding strategies failed. (Type is String)
  
  coordinates: delta_time reference_pt_lat reference_pt_lon (Type is String)
  
  flag_meanings: succeeded_using_pe succeeded_using_flagged_pe failed (Type is String)
  
  flag_values: 0, 1, 3 (Type is Int8)
- segment_id[ /gt3r/segment_quality/delta_time= 0..201] (Type is Int32)
  attributes
  
  long_name: Reference Point, m (Type is String)
  
  units: 1 (Type is String)
  
  source: ATL06 ATBD - segment_quality group (Type is String)
  
  contentType: referenceInformation (Type is String)
  
  description: Segment number corresponding to the second of two ATL03 segments in the ATL06 segment, counted from the RGT equator crossing (Type is String)
  
  coordinates: delta_time reference_pt_lat reference_pt_lon (Type is String)
- signal_selection_status(Type is Group)
  attributes
  
  description: The signal selection status subgroup contains the success or failure for each surface-finding strategies (Type is String)
  
  data_rate: Data within this group are stored at the ICESat-2 20m segment rate. (Type is String)
  signal_selection_status_all[ /gt3r/segment_quality/delta_time= 0..201] (Type is Int8)
  
  attributes
  
  units: 1 (Type is String)
  
  long_name: Signal Selection Status Flag (Type is String)
  
  source: ATL06 ATBD - Signal selection base on ATL03 flags (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 3 (Type is Int8)
  
  contentType: qualityInformation (Type is String)
  
  description: Indicates confidence of the signal-selection algorithm using all ATL03-flagged PEs. 0=Signal selection succeeded using all ATL03-flagged PEs (or algorithm not attempted); 1=Signal selection using all ATL03-flagged PEs failed the 20-meter-spread test; 2=Signal selection using all ATL03-flagged PEs failed the 10-photon-count test; 3=Signal selection using all ATL03-flagged PEs failed both tests (Type is String)
  
  coordinates: ../delta_time ../reference_pt_lat ../reference_pt_lon (Type is String)
  
  flag_meanings: succeeded failed_20 failed_10 failed_both (Type is String)
  
  flag_values: 0, 1, 2, 3 (Type is Int8)
  
  signal_selection_status_confident[ /gt3r/segment_quality/delta_time= 0..201] (Type is Int8)
  
  attributes
  
  units: 1 (Type is String)
  
  long_name: Signal Selection Confident Flag (Type is String)
  
  source: ATL06 ATBD - Signal selection base on ATL03 flags (Type is String)
  
  valid_min: 0 (Type is Int8)
  
  valid_max: 3 (Type is Int8)
  
  contentType: qualityInformation (Type is String)
  
  description: Indicates confidence of the signal-selection algorithm using low or better PEs. 0=Signal selection succeeded using ATL03 low-or-better confidence PEs; 1=Signal selection using ATL03 low-or-better confidence PEs failed the 20-meter-spread test; 2=Signal selection using ATL03 low-or-better confidence PEs failed the 10-photon-count test; 3=Signal selection using ATL03 low-or-better confidence PEs failed both tests (Type is String)
  
  coordinates: ../delta_time ../reference_pt_lat ../reference_pt_lon (Type is String)
  
  flag_meanings: succeeded failed_20 failed_10 failed_both (Type is String)
  
  flag_values: 0, 1, 2, 3 (Type is Int8)

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Global Attributes	View/Hide short_name: ATL06 (Type is String) level: L3A (Type is String) description: This data set (ATL06) provides geolocated, land-ice surface heights (above the WGS 84 ellipsoid, ITRF2014 reference frame), plus ancillary parameters that can be used to interpret and assess the quality of the height estimates. The data were acquired by th (Type is String) Conventions: CF-1.6 (Type is String) contributor_name: Thomas A Neumann (thomas.neumann@nasa.gov), Thorsten Markus (thorsten.markus@nasa.gov), Suneel Bhardwaj (suneel.bhardwaj@nasa.gov) David W Hancock III (david.w.hancock@nasa.gov) (Type is String) contributor_role: Instrument Engineer, Investigator, Principle Investigator, Data Producer, Data Producer (Type is String) data_rate: Data within this group pertain to the granule in its entirety. (Type is String) date_type: UTC (Type is String) featureType: trajectory (Type is String) geospatial_lat_units: degrees_north (Type is String) geospatial_lon_units: degrees_east (Type is String) granule_type: ATL06 (Type is String) identifier_product_doi_authority: http://dx.doi.org (Type is String) license: Data may not be reproduced or distributed without including the citation for this product included in this metadata. Data may not be distributed in an altered form without the written permission of the ICESat-2 Science Project Office at NASA/GSFC. (Type is String) naming_authority: http://dx.doi.org (Type is String) spatial_coverage_type: Horizontal (Type is String) standard_name_vocabulary: CF-1.6 (Type is String) time_type: CCSDS UTC-A (Type is String) date_created: 2025-12-19T22:01:54.000000Z (Type is String) hdfversion: HDF5 1.14.4 (Type is String) history: 2025-12-19T22:01:54.000000Z;fe870c8f-7533-3a33-8c17-d667ecdd83b6;Created by PGE atlas_l3a_is Version 5.1 (Type is String) identifier_file_uuid: fe870c8f-7533-3a33-8c17-d667ecdd83b6 (Type is String) identifier_product_format_version: 5.1 (Type is String) time_coverage_duration: 422. (Type is Float64) time_coverage_end: 2025-09-13T14:30:26.000000Z (Type is String) time_coverage_start: 2025-09-13T14:23:24.000000Z (Type is String) geospatial_lat_min: 25.474481959584711 (Type is Float64) geospatial_lon_min: -171.42912310348692 (Type is Float64) geospatial_lat_max: 25.51268125829365 (Type is Float64) geospatial_lon_max: -171.42503689992421 (Type is Float64) publisher_name: NSIDC DAAC > NASA National Snow and Ice Data Center Distributed Active Archive Center (Type is String) publisher_email: nsidc@nsidc.org (Type is String) publisher_url: http://nsidc.org/daac/ (Type is String) title: ATLAS/ICESat-2 L3A Land Ice Height (Type is String) identifier_product_type: ATL06 (Type is String) identifier_product_doi: doi:10.5067/ATLAS/ATL06.007 (Type is String) institution: National Aeronautics and Space Administration (NASA) (Type is String) creator_name: GSFC I-SIPS > ICESat-2 Science Investigator-led Processing System (Type is String) summary: ATL06 provides estimates of the ice-sheet mean surface height relative to the WGS-84 ellipsoid, and ancillary parameters needed to interpret and assess the quality of these height estimates. (Type is String) keywords: EARTH SCIENCE > CRYOSPHERE > GLACIERS/ICE SHEETS > GLACIER ELEVATION/ICE SHEET ELEVATION > NONE > NONE > NONE (Type is String) keywords_vocabulary: NASA/GCMD Science Keywords (Type is String) citation: Cite these data in publications as follows: The data used in this study were produced by the ICESat-2 Science Project Office at NASA/GSFC. The data archive site is the NASA National Snow and Ice Data Center Distributed Active Archive Center. (Type is String) processing_level: 3A (Type is String) references: http://nsidc.org/data/icesat2/data.html (Type is String) project: ICESat-2 > Ice, Cloud, and land Elevation Satellite-2 (Type is String) instrument: ATLAS > Advanced Topographic Laser Altimeter System (Type is String) platform: ICESat-2 > Ice, Cloud, and land Elevation Satellite-2 (Type is String) source: Spacecraft (Type is String)

Global Dimensions	None

Variables	ancillary_data(Type is Group) attributes data_rate: Data within this group pertain to the granule in its entirety. (Type is String) description: Contains information ancillary to the data product. This may include product characteristics, instrument characteristics and/or processing constants. (Type is String) release[ 0..0] (Type is String) attributes long_name: Release Number (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Release number of the granule. The release number is incremented when the software or ancillary data used to create the granule has been changed. (Type is String) end_geoseg[ 0..0] (Type is Int32) attributes long_name: Ending Geolocation Segment (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: The ending geolocation segment number associated with the data contained within this granule. ICESat granule geographic regions are further refined by geolocation segments. During the geolocation process, a geolocation segment is created approximately every 20m from the start of the orbit to the end. The geolocation segments help align the ATLAS strong a weak beams and provide a common segment length for the L2 and higher products. The geolocation segment indices differ slightly from orbit-to-orbit because of the irregular shape of the Earth. The geolocation segment indices on ATL01 and ATL02 are only approximate because beams have not been aligned at the time of their creation. (Type is String) version[ 0..0] (Type is String) attributes long_name: Version (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Version number of this granule within the release. It is a sequential number corresponding to the number of times the granule has been reprocessed for the current release. (Type is String) end_region[ 0..0] (Type is Int32) attributes long_name: Ending Region (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: The ending product-specific region number associated with the data contained within this granule. ICESat-2 data products are separated by geographic regions. The data contained within a specific region are the same for ATL01 and ATL02. ATL03 regions differ slightly because of different geolocation segment locations caused by the irregular shape of the Earth. The region indices for other products are completely independent. (Type is String) atlas_sdp_gps_epoch[ 0..0] (Type is Float64) attributes long_name: ATLAS Epoch Offset (Type is String) units: seconds since 1980-01-06T00:00:00.000000Z (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS Standard Data Product (SDP) epoch (2018-01-01:T00.00.00.000000 UTC). Add this value to delta time parameters to compute full gps_seconds (relative to the GPS epoch) for each data point. (Type is String) end_rgt[ 0..0] (Type is Int32) attributes long_name: Ending Reference Groundtrack (Type is String) units: 1 (Type is String) source: Derived (Type is String) valid_min: 1 (Type is Int32) valid_max: 1387 (Type is Int32) contentType: auxiliaryInformation (Type is String) description: The ending reference groundtrack (RGT) number associated with the data contained within this granule. There are 1387 reference groundtrack in the ICESat-2 repeat orbit. The reference groundtrack increments each time the spacecraft completes a full orbit of the Earth and resets to 1 each time the spacecraft completes a full cycle. (Type is String) end_delta_time[ 0..0] (Type is Float64) attributes long_name: ATLAS End Time (Actual) (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of GPS seconds since the ATLAS SDP epoch at the last data point in the file. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) end_orbit[ 0..0] (Type is Int32) attributes long_name: Ending Orbit Number (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: The ending orbit number associated with the data contained within this granule. The orbit number increments each time the spacecraft completes a full orbit of the Earth. (Type is String) start_cycle[ 0..0] (Type is Int32) attributes long_name: Starting Cycle (Type is String) units: 1 (Type is String) source: Derived (Type is String) valid_min: 0 (Type is Int32) valid_max: 99 (Type is Int32) contentType: auxiliaryInformation (Type is String) description: The starting cycle number associated with the data contained within this granule. The cycle number is the counter of the number of 91-day repeat cycles completed by the mission. (Type is String) data_end_utc[ 0..0] (Type is String) attributes long_name: End UTC Time of Granule (CCSDS-A, Actual) (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: UTC (in CCSDS-A format) of the last data point within the granule. (Type is String) control[ 0..0] (Type is String) attributes long_name: Control File (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: PGE-specific control file used to generate this granule. To re-use, replace breaks (BR) with linefeeds. (Type is String) start_gpssow[ 0..0] (Type is Float64) attributes long_name: Start GPS SOW of Granule (Actual) (Type is String) units: seconds (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: GPS seconds-of-week of the first data point in the granule. (Type is String) granule_end_utc[ 0..0] (Type is String) attributes long_name: End UTC Time of Granule (CCSDS-A, Requested) (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Requested end time (in UTC CCSDS-A) of this granule. (Type is String) end_cycle[ 0..0] (Type is Int32) attributes long_name: Ending Cycle (Type is String) units: 1 (Type is String) source: Derived (Type is String) valid_min: 0 (Type is Int32) valid_max: 99 (Type is Int32) contentType: auxiliaryInformation (Type is String) description: The ending cycle number associated with the data contained within this granule. The cycle number is the counter of the number of 91-day repeat cycles completed by the mission. (Type is String) granule_start_utc[ 0..0] (Type is String) attributes long_name: Start UTC Time of Granule (CCSDS-A, Requested) (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Requested start time (in UTC CCSDS-A) of this granule. (Type is String) start_delta_time[ 0..0] (Type is Float64) attributes long_name: ATLAS Start Time (Actual) (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of GPS seconds since the ATLAS SDP epoch at the first data point in the file. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) start_geoseg[ 0..0] (Type is Int32) attributes long_name: Starting Geolocation Segment (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: The starting geolocation segment number associated with the data contained within this granule. ICESat granule geographic regions are further refined by geolocation segments. During the geolocation process, a geolocation segment is created approximately every 20m from the start of the orbit to the end. The geolocation segments help align the ATLAS strong a weak beams and provide a common segment length for the L2 and higher products. The geolocation segment indices differ slightly from orbit-to-orbit because of the irregular shape of the Earth. The geolocation segment indices on ATL01 and ATL02 are only approximate because beams have not been aligned at the time of their creation. (Type is String) start_orbit[ 0..0] (Type is Int32) attributes long_name: Starting Orbit Number (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: The starting orbit number associated with the data contained within this granule. The orbit number increments each time the spacecraft completes a full orbit of the Earth. (Type is String) data_start_utc[ 0..0] (Type is String) attributes long_name: Start UTC Time of Granule (CCSDS-A, Actual) (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: UTC (in CCSDS-A format) of the first data point within the granule. (Type is String) end_gpsweek[ 0..0] (Type is Int32) attributes long_name: Ending GPSWeek of Granule (Actual) (Type is String) contentType: auxiliaryInformation (Type is String) description: GPS week number of the last data point in the granule. (Type is String) units: weeks from 1980-01-06 (Type is String) source: Derived (Type is String) start_rgt[ 0..0] (Type is Int32) attributes long_name: Starting Reference Groundtrack (Type is String) units: 1 (Type is String) source: Derived (Type is String) valid_min: 1 (Type is Int32) valid_max: 1387 (Type is Int32) contentType: auxiliaryInformation (Type is String) description: The starting reference groundtrack (RGT) number associated with the data contained within this granule. There are 1387 reference groundtrack in the ICESat-2 repeat orbit. The reference groundtrack increments each time the spacecraft completes a full orbit of the Earth and resets to 1 each time the spacecraft completes a full cycle. (Type is String) end_gpssow[ 0..0] (Type is Float64) attributes long_name: Ending GPS SOW of Granule (Actual) (Type is String) units: seconds (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: GPS seconds-of-week of the last data point in the granule. (Type is String) qa_at_interval[ 0..0] (Type is Float64) attributes long_name: QA Along-Track Interval (Type is String) units: seconds/cell (Type is String) source: control (Type is String) contentType: auxiliaryInformation (Type is String) description: Statistics time interval for along-track QA data. (Type is String) start_region[ 0..0] (Type is Int32) attributes long_name: Starting Region (Type is String) units: 1 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: The starting product-specific region number associated with the data contained within this granule. ICESat-2 data products are separated by geographic regions. The data contained within a specific region are the same for ATL01 and ATL02. ATL03 regions differ slightly because of different geolocation segment locations caused by the irregular shape of the Earth. The region indices for other products are completely independent. (Type is String) start_gpsweek[ 0..0] (Type is Int32) attributes long_name: Start GPSWeek of Granule (Actual) (Type is String) units: weeks from 1980-01-06 (Type is String) source: Derived (Type is String) contentType: auxiliaryInformation (Type is String) description: GPS week number of the first data point in the granule. (Type is String) land_ice(Type is Group) attributes description: Contains land-ice-specific information ancillary to the data product. This may include product characteristics, instrument characteristics and/or processing constants. (Type is String) rbin_width[ 0..0] (Type is Float32) attributes long_name: Bin Size (Type is String) units: meters (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Residual histogram bin size (Type is String) sigma_beam[ 0..0] (Type is Float32) attributes long_name: Sigma of Gaussian Footprint (Type is String) units: meters (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Spatial sigma of the Gaussian footprint (m) (Type is String) qs_lim_hsigma[ 0..0] (Type is Float32) attributes long_name: Height Sigma QS Limit (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: atl06_quality_summary limit for testing Height Sigma. (Type is String) fit_maxiter[ 0..0] (Type is Int32) attributes long_name: Maximum Iterations of Fit (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Maximum number of iterations in at_seg_fit (Type is String) txp_maxiter[ 0..0] (Type is Int32) attributes long_name: Maximum Iterations (Type is String) units: counts (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Maximum number of iterations in tx_shape_corr (Type is String) qs_lim_hrs[ 0..0] (Type is Float32) attributes long_name: Height Robust Spread QS Limit (Type is String) units: meters (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: atl06_quality_summary limit for testing Height Robust Spread. (Type is String) qs_lim_bsc[ 0..0] (Type is Int32) attributes long_name: Blowing Snow Confidence QS Limit (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: atl06_quality_summary limit for testing Blowing Snow Confidence. (Type is String) qs_lim_snr[ 0..0] (Type is Float32) attributes long_name: SNR Significance QS Limit (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: atl06_quality_summary limit for testing SNR Significance. (Type is String) n_hist[ 0..0] (Type is Int32) attributes long_name: Number of Histogram Bins (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of bins in a histogram (Type is String) min_gain_th[ 0..0] (Type is Float32) attributes long_name: Minimum Gain Threshold (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Minimum estimated gain threshold (3.1.6) (Type is String) qs_lim_sss[ 0..0] (Type is Int32) attributes long_name: Signal Selection Source QS Limit (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: atl06_quality_summary limit for testing Signal Selection Source. (Type is String) n_sigmas[ 0..0] (Type is Float32) attributes long_name: Number of Sigmas (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Multiplied by sigma_expected to get h_win (Type is String) dt_hist[ 0..0] (Type is Float64) attributes long_name: Histogram Bin Size (Type is String) units: seconds (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Bin size for histograms (sec) (Type is String) sigma_tx[ 0..5] (Type is Float32) attributes long_name: Sigma Tx (Type is String) units: seconds (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: RDE of the Tx pulse in ATLAS Spot order (1-6). Calculated as half the difference between the 84th and 16th percentiles of the signal bins. (Type is String) min_signal_conf[ 0..0] (Type is Int32) attributes long_name: Minimum Signal Confidence (Type is String) units: 1 (Type is String) source: Operations (Type is String) valid_min: 0 (Type is Int32) valid_max: 4 (Type is Int32) contentType: auxiliaryInformation (Type is String) description: Minimum signal confidence level for a photon to be considered valid. (Type is String) t_dead[ 0..5] (Type is Float32) attributes long_name: Dead Time (Type is String) units: seconds (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Dead time, in ATLAS spot order (1-6). Calculated as the average of the CAL42 per-channel dead times, using the appropriate channels for strong and weak spots. (Type is String) qs_lim_msw[ 0..0] (Type is Int32) attributes long_name: Multiple Scattering Warning QS Limit (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: atl06_quality_summary limit for testing Multiple Scattering Warning. (Type is String) min_n_sel[ 0..0] (Type is Int32) attributes long_name: Mininum Number of Photons (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Minimum number of selected PEs in pe_select (Type is String) max_res_ids[ 0..0] (Type is Int32) attributes long_name: Max Segments (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Maximum number of segment ids in each residual_histogram (Type is String) proc_interval[ 0..0] (Type is Int32) attributes long_name: Processing Interval (Type is String) units: seconds (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Processing interval in number of geolocation segments.. (Type is String) fpb_maxiter[ 0..0] (Type is Int32) attributes long_name: Maximum Iterations for FPB (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Maximum number of iterations in fpb_corr (Type is String) min_n_pe[ 0..0] (Type is Int32) attributes long_name: Minimum Photons (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Minimum # PEs for fit (Type is String) min_dist[ 0..0] (Type is Float32) attributes long_name: Minimum Distance (Type is String) units: meters (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Min dist between first and last selected PEs (Type is String) nhist_bins[ 0..0] (Type is Int32) attributes long_name: Number of Bins (Type is String) units: 1 (Type is String) source: Operations (Type is String) contentType: auxiliaryInformation (Type is String) description: Number of bins in residual histogram (Type is String) quality_assessment(Type is Group) attributes description: Contains quality assessment data. This may include QA counters, QA along-track data and/or QA summary data. (Type is String) qa_granule_fail_reason[ 0..0] (Type is Int32) attributes long_name: Granule Failure Reason (Type is String) units: 1 (Type is String) source: Operations (Type is String) valid_min: 0 (Type is Int32) valid_max: 5 (Type is Int32) contentType: qualityInformation (Type is String) description: Flag indicating granule failure reason. 0=no failure; 1=processing error; 2=Insufficient output data was generated; 3=TBD Failure; 4=TBD_Failure; 5=other failure. (Type is String) flag_meanings: no_failure PROCESS_ERROR INSUFFICIENT_OUTPUT failure_3 failure_4 OTHER_FAILURE (Type is String) flag_values: 0, 1, 2, 3, 4, 5 (Type is Int32) qa_granule_pass_fail[ 0..0] (Type is Int32) attributes long_name: Granule Pass Flag (Type is String) units: 1 (Type is String) source: Operations (Type is String) valid_min: 0 (Type is Int32) valid_max: 1 (Type is Int32) contentType: qualityInformation (Type is String) description: Flag indicating granule quality. 0=granule passes automatic QA. 1=granule fails automatic QA. (Type is String) flag_meanings: PASS FAIL (Type is String) flag_values: 0, 1 (Type is Int32) gt1r(Type is Group) attributes description: Contains quality assessment data. This may include QA counters, QA along-track data and/or QA summary data. (Type is String) Dimensions: [ /quality_assessment/gt1r/delta_time = 0..-1 ] lon_mean[ 0..-1] (Type is Float64) attributes long_name: Longitude Mean (Type is String) standard_name: longitude (Type is String) units: degrees_east (Type is String) source: Section 7.2, Q/A Statistics (Type is String) valid_min: -180. (Type is Float64) valid_max: 180. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Mean longitude of the 10km segment. (Type is String) coordinates: delta_time lat_mean (Type is String) lat_mean[ 0..-1] (Type is Float64) attributes long_name: Latitude Mean (Type is String) standard_name: latitude (Type is String) units: degrees_north (Type is String) source: Section 7.2, Q/A Statistics (Type is String) valid_min: -90. (Type is Float64) valid_max: 90. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Mean latitude of the 10km segment. (Type is String) coordinates: delta_time lon_mean (Type is String) delta_time[ /quality_assessment/gt1r/delta_time= 0..-1] (Type is Float64) attributes long_name: Elapsed GPS seconds (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: Section 7.2, Q/A Statistics (Type is String) contentType: referenceInformation (Type is String) description: Mean number of GPS seconds since the ATLAS SDP epoch for the 10km segment. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: lat_mean lon_mean (Type is String) signal_selection_source_fraction_0[ 0..-1] (Type is Float32) attributes long_name: Signal Selection Source Fraction 0 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to zero. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_2[ 0..-1] (Type is Float32) attributes long_name: Signal Selection Source Fraction 2 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 2. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_1[ 0..-1] (Type is Float32) attributes long_name: Signal Selection Source Fraction 1 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 1. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_3[ 0..-1] (Type is Float32) attributes long_name: Signal Selection Source Fraction 3 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 3. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) gt2r(Type is Group) attributes description: Contains quality assessment data. This may include QA counters, QA along-track data and/or QA summary data. (Type is String) Dimensions: [ /quality_assessment/gt2r/delta_time = 0..-1 ] lon_mean[ 0..-1] (Type is Float64) attributes long_name: Longitude Mean (Type is String) standard_name: longitude (Type is String) units: degrees_east (Type is String) source: Section 7.2, Q/A Statistics (Type is String) valid_min: -180. (Type is Float64) valid_max: 180. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Mean longitude of the 10km segment. (Type is String) coordinates: delta_time lat_mean (Type is String) delta_time[ /quality_assessment/gt2r/delta_time= 0..-1] (Type is Float64) attributes long_name: Elapsed GPS seconds (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: Section 7.2, Q/A Statistics (Type is String) contentType: referenceInformation (Type is String) description: Mean number of GPS seconds since the ATLAS SDP epoch for the 10km segment. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: lat_mean lon_mean (Type is String) lat_mean[ 0..-1] (Type is Float64) attributes long_name: Latitude Mean (Type is String) standard_name: latitude (Type is String) units: degrees_north (Type is String) source: Section 7.2, Q/A Statistics (Type is String) valid_min: -90. (Type is Float64) valid_max: 90. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Mean latitude of the 10km segment. (Type is String) coordinates: delta_time lon_mean (Type is String) signal_selection_source_fraction_0[ 0..-1] (Type is Float32) attributes long_name: Signal Selection Source Fraction 0 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to zero. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_2[ 0..-1] (Type is Float32) attributes long_name: Signal Selection Source Fraction 2 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 2. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_1[ 0..-1] (Type is Float32) attributes long_name: Signal Selection Source Fraction 1 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 1. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_3[ 0..-1] (Type is Float32) attributes long_name: Signal Selection Source Fraction 3 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 3. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) gt1l(Type is Group) attributes description: Contains quality assessment data. This may include QA counters, QA along-track data and/or QA summary data. (Type is String) Dimensions: [ /quality_assessment/gt1l/delta_time = 0..-1 ] lon_mean[ 0..-1] (Type is Float64) attributes long_name: Longitude Mean (Type is String) standard_name: longitude (Type is String) units: degrees_east (Type is String) source: Section 7.2, Q/A Statistics (Type is String) valid_min: -180. (Type is Float64) valid_max: 180. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Mean longitude of the 10km segment. (Type is String) coordinates: delta_time lat_mean (Type is String) lat_mean[ 0..-1] (Type is Float64) attributes long_name: Latitude Mean (Type is String) standard_name: latitude (Type is String) units: degrees_north (Type is String) source: Section 7.2, Q/A Statistics (Type is String) valid_min: -90. (Type is Float64) valid_max: 90. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Mean latitude of the 10km segment. (Type is String) coordinates: delta_time lon_mean (Type is String) delta_time[ /quality_assessment/gt1l/delta_time= 0..-1] (Type is Float64) attributes long_name: Elapsed GPS seconds (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: Section 7.2, Q/A Statistics (Type is String) contentType: referenceInformation (Type is String) description: Mean number of GPS seconds since the ATLAS SDP epoch for the 10km segment. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: lat_mean lon_mean (Type is String) signal_selection_source_fraction_0[ 0..-1] (Type is Float32) attributes long_name: Signal Selection Source Fraction 0 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to zero. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_2[ 0..-1] (Type is Float32) attributes long_name: Signal Selection Source Fraction 2 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 2. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_1[ 0..-1] (Type is Float32) attributes long_name: Signal Selection Source Fraction 1 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 1. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_3[ 0..-1] (Type is Float32) attributes long_name: Signal Selection Source Fraction 3 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 3. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) gt3l(Type is Group) attributes description: Contains quality assessment data. This may include QA counters, QA along-track data and/or QA summary data. (Type is String) Dimensions: [ /quality_assessment/gt3l/delta_time = 0..21 ] lon_mean[ /quality_assessment/gt3l/delta_time= 0..21] (Type is Float64) attributes long_name: Longitude Mean (Type is String) standard_name: longitude (Type is String) units: degrees_east (Type is String) source: Section 7.2, Q/A Statistics (Type is String) valid_min: -180. (Type is Float64) valid_max: 180. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Mean longitude of the 10km segment. (Type is String) coordinates: delta_time lat_mean (Type is String) delta_time[ /quality_assessment/gt3l/delta_time= 0..21] (Type is Float64) attributes long_name: Elapsed GPS seconds (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: Section 7.2, Q/A Statistics (Type is String) contentType: referenceInformation (Type is String) description: Mean number of GPS seconds since the ATLAS SDP epoch for the 10km segment. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: lat_mean lon_mean (Type is String) lat_mean[ /quality_assessment/gt3l/delta_time= 0..21] (Type is Float64) attributes long_name: Latitude Mean (Type is String) standard_name: latitude (Type is String) units: degrees_north (Type is String) source: Section 7.2, Q/A Statistics (Type is String) valid_min: -90. (Type is Float64) valid_max: 90. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Mean latitude of the 10km segment. (Type is String) coordinates: delta_time lon_mean (Type is String) signal_selection_source_fraction_0[ /quality_assessment/gt3l/delta_time= 0..21] (Type is Float32) attributes long_name: Signal Selection Source Fraction 0 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to zero. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_2[ /quality_assessment/gt3l/delta_time= 0..21] (Type is Float32) attributes long_name: Signal Selection Source Fraction 2 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 2. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_1[ /quality_assessment/gt3l/delta_time= 0..21] (Type is Float32) attributes long_name: Signal Selection Source Fraction 1 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 1. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_3[ /quality_assessment/gt3l/delta_time= 0..21] (Type is Float32) attributes long_name: Signal Selection Source Fraction 3 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 3. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) gt2l(Type is Group) attributes description: Contains quality assessment data. This may include QA counters, QA along-track data and/or QA summary data. (Type is String) Dimensions: [ /quality_assessment/gt2l/delta_time = 0..-1 ] lon_mean[ 0..-1] (Type is Float64) attributes long_name: Longitude Mean (Type is String) standard_name: longitude (Type is String) units: degrees_east (Type is String) source: Section 7.2, Q/A Statistics (Type is String) valid_min: -180. (Type is Float64) valid_max: 180. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Mean longitude of the 10km segment. (Type is String) coordinates: delta_time lat_mean (Type is String) delta_time[ /quality_assessment/gt2l/delta_time= 0..-1] (Type is Float64) attributes long_name: Elapsed GPS seconds (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: Section 7.2, Q/A Statistics (Type is String) contentType: referenceInformation (Type is String) description: Mean number of GPS seconds since the ATLAS SDP epoch for the 10km segment. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: lat_mean lon_mean (Type is String) lat_mean[ 0..-1] (Type is Float64) attributes long_name: Latitude Mean (Type is String) standard_name: latitude (Type is String) units: degrees_north (Type is String) source: Section 7.2, Q/A Statistics (Type is String) valid_min: -90. (Type is Float64) valid_max: 90. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Mean latitude of the 10km segment. (Type is String) coordinates: delta_time lon_mean (Type is String) signal_selection_source_fraction_0[ 0..-1] (Type is Float32) attributes long_name: Signal Selection Source Fraction 0 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to zero. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_2[ 0..-1] (Type is Float32) attributes long_name: Signal Selection Source Fraction 2 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 2. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_1[ 0..-1] (Type is Float32) attributes long_name: Signal Selection Source Fraction 1 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 1. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_3[ 0..-1] (Type is Float32) attributes long_name: Signal Selection Source Fraction 3 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 3. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) gt3r(Type is Group) attributes description: Contains quality assessment data. This may include QA counters, QA along-track data and/or QA summary data. (Type is String) Dimensions: [ /quality_assessment/gt3r/delta_time = 0..21 ] lon_mean[ /quality_assessment/gt3r/delta_time= 0..21] (Type is Float64) attributes long_name: Longitude Mean (Type is String) standard_name: longitude (Type is String) units: degrees_east (Type is String) source: Section 7.2, Q/A Statistics (Type is String) valid_min: -180. (Type is Float64) valid_max: 180. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Mean longitude of the 10km segment. (Type is String) coordinates: delta_time lat_mean (Type is String) delta_time[ /quality_assessment/gt3r/delta_time= 0..21] (Type is Float64) attributes long_name: Elapsed GPS seconds (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: Section 7.2, Q/A Statistics (Type is String) contentType: referenceInformation (Type is String) description: Mean number of GPS seconds since the ATLAS SDP epoch for the 10km segment. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: lat_mean lon_mean (Type is String) lat_mean[ /quality_assessment/gt3r/delta_time= 0..21] (Type is Float64) attributes long_name: Latitude Mean (Type is String) standard_name: latitude (Type is String) units: degrees_north (Type is String) source: Section 7.2, Q/A Statistics (Type is String) valid_min: -90. (Type is Float64) valid_max: 90. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Mean latitude of the 10km segment. (Type is String) coordinates: delta_time lon_mean (Type is String) signal_selection_source_fraction_0[ /quality_assessment/gt3r/delta_time= 0..21] (Type is Float32) attributes long_name: Signal Selection Source Fraction 0 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to zero. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_2[ /quality_assessment/gt3r/delta_time= 0..21] (Type is Float32) attributes long_name: Signal Selection Source Fraction 2 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 2. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_1[ /quality_assessment/gt3r/delta_time= 0..21] (Type is Float32) attributes long_name: Signal Selection Source Fraction 1 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 1. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) signal_selection_source_fraction_3[ /quality_assessment/gt3r/delta_time= 0..21] (Type is Float32) attributes long_name: Signal Selection Source Fraction 3 (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Q/A Statistics (Type is String) valid_min: 0. (Type is Float32) valid_max: 1. (Type is Float32) contentType: qualityInformation (Type is String) description: The fraction of 20m segments with signal_selection_source equal to 3. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) METADATA(Type is Group) attributes Description: ISO19115 Structured Metadata Represented within HDF5 (Type is String) iso_19139_dataset_xml[ 0..0] (Type is String) attributes long_name: ISO 19139 Dataset XML (Type is String) description: ISO 19139 Dataset XML (Type is String) iso_19139_series_xml[ 0..0] (Type is String) attributes long_name: ISO 19139 Series XML (Type is String) description: ISO 19139 Series XML (Type is String) AcquisitionInformation(Type is Group) no attributes lidar(Type is Group) attributes pulse_rate: 10000 pps (Type is String) wavelength: 532 nm (Type is String) identifier: ATLAS (Type is String) type: Laser Altimeter (Type is String) description: ATLAS on ICESat-2 determines the range between the satellite and the Earth's surface by measuring the two-way time delay of short pulses of laser light that it transmits in six beams. It is different from previous operational ice-sheet altimeters in that it is a photon-counting LIDAR. ATLAS records a set of arrival times for individual photons, which are then analyzed to derive surface, vegetation, and cloud properties. ATLAS has six beams arranged in three pairs, so that it samples each of three reference pair tracks with a pair of beams; ATLAS transmits pulses at 10 kHz, giving approximately one pulse every 0.7 m along track; ATLAS's expected pointing control will be better than 90 m RMS. (Type is String) lidarDocument(Type is Group) attributes edition: Pre-Release (Type is String) publicationDate: 12/31/17 (Type is String) title: A document describing the ATLAS instrument will be provided by the ICESat-2 Project Science Office. (Type is String) platform(Type is Group) attributes identifier: ICESat-2 (Type is String) description: Ice, Cloud, and land Elevation Satellite-2 (Type is String) type: Spacecraft (Type is String) platformDocument(Type is Group) attributes edition: 31-Dec-16 (Type is String) publicationDate: 31-Dec-16 (Type is String) title: The Ice, Cloud, and land Elevation Satellite-2 (ICESat-2): Science requirements, concept, and implementation. Thorsten Markus, Tom Neumann, Anthony Martino, Waleed Abdalati, Kelly Brunt, Beata Csatho, Sinead Farrell, Helen Fricker, Alex Gardner, David Harding, Michael Jasinski, Ron Kwok, Lori Magruder, Dan Lubin, Scott Luthcke, James Morison, Ross Nelson, Amy Neuenschwander, Stephen Palm, Sorin Popescu, CK Shum, Bob E. Schutz, Benjamin Smith, Yuekui Yang, Jay Zwally. http://dx.doi.org/10.1016/j.rse.2016.12.029 (Type is String) DataQuality(Type is Group) attributes scope: NOT_SET (Type is String) CompletenessOmission(Type is Group) attributes evaluationMethodType: directInternal (Type is String) measureDescription: TBD (Type is String) nameOfMeasure: TBD (Type is String) unitofMeasure: TBD (Type is String) value: NOT_SET (Type is String) DomainConsistency(Type is Group) attributes evaluationMethodType: directInternal (Type is String) measureDescription: TBD (Type is String) nameOfMeasure: TBD (Type is String) unitofMeasure: TBD (Type is String) value: NOT_SET (Type is String) ProductSpecificationDocument(Type is Group) attributes ShortName: ATL06_SDP (Type is String) characterSet: utf8 (Type is String) language: eng (Type is String) publicationDate: Feb 2020 (Type is String) title: ICESat-2-SIPS-SPEC-4260 - ATLAS Science Algorithm Standard Data Product (SDP) Volume 5 (ATL06). (Type is String) edition: v4.3 (Type is String) SeriesIdentification(Type is Group) attributes maintenanceAndUpdateFrequency: asNeeded (Type is String) maintenanceDate: SET_BY_META (Type is String) VersionID: 007 (Type is String) language: eng (Type is String) characterSet: utf8 (Type is String) pointOfContact: NSIDC DAAC > NASA National Snow and Ice Data Center Distributed Active Archive Center (Type is String) longName: ATLAS/ICESat-2 L3A Land Ice Height (Type is String) shortName: ATL06 (Type is String) identifier_product_DOI: doi:10.5067/ATLAS/ATL06.007 (Type is String) revisionDate: 2022-08-09 (Type is String) resourceProviderOrganizationName: National Aeronautics and Space Administration (NASA) (Type is String) abstract: ATL06 provides estimates of the ice-sheet mean surface height relative to the WGS-84 ellipsoid, and ancillary parameters needed to interpret and assess the quality of these height estimates. (Type is String) purpose: ATL06 provides estimates of the ice-sheet mean surface height relative to the WGS-84 ellipsoid, and ancillary parameters needed to interpret and assess the quality of these height estimates. (Type is String) credit: The software that generates the ATL06 product was designed and implemented at the NASA Wallops Flight Facility in Wallops Island, Virginia. (Type is String) status: onGoing (Type is String) format: HDF (Type is String) formatVersion: 5 (Type is String) topicCategory: geoscientificInformation (Type is String) mission: ICESat-2 > Ice, Cloud, and land Elevation Satellite-2 (Type is String) DatasetIdentification(Type is Group) attributes spatialRepresentationType: along-track (Type is String) creationDate: 2025-12-19T22:01:54.000000Z (Type is String) uuid: fe870c8f-7533-3a33-8c17-d667ecdd83b6 (Type is String) fileName: ATL06_20250913142324_13722807_007_01.h5 (Type is String) VersionID: 007 (Type is String) language: eng (Type is String) characterSet: utf8 (Type is String) shortName: ATL06 (Type is String) originatorOrganizationName: GSFC I-SIPS > ICESat-2 Science Investigator-led Processing System (Type is String) abstract: ATL06 provides estimates of the ice-sheet mean surface height relative to the WGS-84 ellipsoid, and ancillary parameters needed to interpret and assess the quality of these height estimates. (Type is String) purpose: ATL06 provides estimates of the ice-sheet mean surface height relative to the WGS-84 ellipsoid, and ancillary parameters needed to interpret and assess the quality of these height estimates. (Type is String) credit: The software that generates the ATL06 product was designed and implemented at the NASA Wallops Flight Facility in Wallops Island, Virginia. (Type is String) status: onGoing (Type is String) topicCategory: geoscientificInformation (Type is String) Extent(Type is Group) attributes northBoundLatitude: 25.51268125829365 (Type is Float64) eastBoundLongitude: -171.42503689992421 (Type is Float64) southBoundLatitude: 25.474481959584711 (Type is Float64) westBoundLongitude: -171.42912310348692 (Type is Float64) rangeBeginningDateTime: 2025-09-13T14:23:47.485874Z (Type is String) rangeEndingDateTime: 2025-09-13T14:23:48.254371Z (Type is String) QADatasetIdentification(Type is Group) attributes creationDate: 2025-12-19T22:01:57.000000Z (Type is String) abstract: An ASCII product that contains statistical information on data product results. These statistics enable data producers and users to assess the quality of the data in the data product granule (Type is String) fileName: ATL06_20250913142324_13722807_007_01.qa (Type is String) Lineage(Type is Group) no attributes ANC36-06(Type is Group) attributes description: ISO 19139 XML file containing Series-level metadata information. (Type is String) fileName: ANC36-06_20250523205141_007_01.xml (Type is String) shortName: ANC36-06 (Type is String) uuid: f486c1c2-b893-34c1-b902-1a59f2688c66 (Type is String) version: 007 (Type is String) Control(Type is Group) attributes description: Text-based keyword=value file generated automatically within the ICESat-2 data system that specifies all of the conditions required for each individual run of the software. (Type is String) fileName: CTL_atlas_l3a_is_021426921.ctl (Type is String) shortName: CNTL (Type is String) version: 1 (Type is String) ANC28(Type is Group) attributes description: DTU Mean Sea Surface re-referenced to the WGS84 ellipsoid. (Type is String) fileName: dtu13_20180705_001_01.nc (Type is String) shortName: ANC28 (Type is String) uuid: 56f47040-a72e-3109-99c2-bc1658e6dda4 (Type is String) version: 20180705 (Type is String) ANC38-06(Type is Group) attributes description: ISO 19139 XML file containing DataSet-level metadata information. (Type is String) fileName: ANC38-06_20250523205142_007_01.xml (Type is String) shortName: ANC38-06 (Type is String) uuid: f8d47ee3-4f43-3070-a6b0-f05ef6bd3cb2 (Type is String) version: 007 (Type is String) ANC06-02(Type is Group) attributes description: ArcticDEM 32m Digital Elevation Model reformatted into HDF5. (Type is String) fileName: arcticdem32m_20190611_001_01.h5 (Type is String) shortName: ANC06-02 (Type is String) uuid: ce07ef72-0bf4-353b-8475-fb568b029905 (Type is String) version: 20190611 (Type is String) ANC06-03(Type is Group) attributes description: REMA Antarctica 100m Digital Elevation Model filled and reformatted into HDF5 (Type is String) fileName: atl06rema100m_20190628_001_01.h5 (Type is String) shortName: ANC06-03 (Type is String) uuid: 3e0a81bd-bbd5-35fa-b868-3254f9355b7f (Type is String) version: 20190628 (Type is String) ANC25-06(Type is Group) attributes description: HDF5 template file that defines the organization and default content of the product. (Type is String) fileName: ANC25-06_20250523205529_051_01.h5 (Type is String) shortName: ANC25-06 (Type is String) uuid: 45545701-8dcb-30dc-9f21-e2ee4e77fe87 (Type is String) version: 051 (Type is String) ANC17(Type is Group) attributes description: Land Ice Height SNR Significance Table (Type is String) fileName: anc17_snr_f_20180626_001_01.h5 (Type is String) shortName: ANC17 (Type is String) uuid: 10e264bc-139a-3737-9f92-29e64e9b858c (Type is String) version: 20180626 (Type is String) ANC26-06(Type is Group) attributes description: HDF5 template file that defines the organization and default content of the product metadata. (Type is String) fileName: ANC26-06_20250523205537_051_01.h5 (Type is String) shortName: ANC26-06 (Type is String) uuid: 438c292c-43ce-3b04-9c33-683805c75ca5 (Type is String) version: 051 (Type is String) ATL03(Type is Group) attributes description: ICESat-2 ATLAS L2A Global Geolocated Photon data products. (Type is String) fileName: ATL03_20250913142324_13722807_007_01.h5 (Type is String) shortName: ATL03 (Type is String) uuid: c48e4feb-e9c5-3553-bdfe-a1a6e367be23 (Type is String) version: 007 (Type is String) start_cycle: 28 (Type is Int32) end_cycle: 28 (Type is Int32) start_orbit: 39022 (Type is Int32) end_orbit: 39022 (Type is Int32) start_rgt: 1372 (Type is Int32) end_rgt: 1372 (Type is Int32) start_region: 7 (Type is Int32) end_region: 7 (Type is Int32) start_geoseg: 852091 (Type is Int32) end_geoseg: 1001793 (Type is Int32) ATL09(Type is Group) attributes description: ICESat-2 ATLAS L3A atmosphere data products. (Type is String) fileName: ATL09_20250913134322_13722801_007_01.h5 (Type is String) shortName: ATL09 (Type is String) uuid: 758cce16-d1d5-3c1c-819f-88e47f7c36e1 (Type is String) version: 007 (Type is String) start_cycle: 28 (Type is Int32) end_cycle: 28 (Type is Int32) start_orbit: 39022 (Type is Int32) end_orbit: 39022 (Type is Int32) start_rgt: 1372 (Type is Int32) end_rgt: 1372 (Type is Int32) start_region: 1 (Type is Int32) end_region: 14 (Type is Int32) start_geoseg: 2 (Type is Int32) end_geoseg: 2007136 (Type is Int32) ANC06-01(Type is Group) attributes description: MERIT 3 arcsec Digital Elevation Model reformatted into HDF5 and re-referenced to the WGS-84 ellipsoid. (Type is String) fileName: merit_3as_20200617_001_01.h5 (Type is String) shortName: ANC06-01 (Type is String) uuid: 3db8ab65-d2ac-37c7-86db-17c762268673 (Type is String) version: 20200617 (Type is String) ANC19(Type is Group) attributes description: TAI to UTC leapsecond file retrieved from ftp://maia.usno.navy.mil/ser7/tai-utc.dat (Type is String) fileName: tai_utc_2017.dat (Type is String) shortName: ANC19 (Type is String) uuid: 7c66d365-278a-31f7-8fe4-9c80e2f012e5 (Type is String) version: 001 (Type is String) ProcessStep(Type is Group) no attributes Browse(Type is Group) attributes processDescription: Browse processing is performed for each granule SIPS produces. The browse utility reads data from the granule and produces browse images as defined in the respective product ATBD. The utility then embeds each browse image into the product within the /Browse group. (Type is String) identifier: atlas_brw (Type is String) softwareVersion: Version 3.1.3 (Type is String) softwareDate: Apr 8 2025 (Type is String) softwareTitle: Creates ATLAS HDF5 browse files (Type is String) runTimeParameters: CTL_atlas_l3a_is_021426921.ctl (Type is String) stepDateTime: 2025-12-19T22:01:57.000000Z (Type is String) Metadata(Type is Group) attributes processDescription: Metadata information is processed by the metadata utility for each granule produced by SIPS. During PGE processing, dynamic metadata are written to the product. Additional static information is provided with the metadata template. The metadata utility reads ISO Dataset and Series metadata files and updates the product with static information from within those files. The utility then merges the static and dynamic metadata to creates output ISO19139 Dataset and Series XML files. Finally the utility reads the ISO19139 Dataset and Series XML files into memory and stores the textual representations as attributes attached to the /METADATA group. (Type is String) identifier: atlas_meta (Type is String) softwareVersion: Version 5.1.3 (Type is String) softwareDate: Apr 8 2025 (Type is String) softwareTitle: Creates ATLAS XML metadata files (Type is String) runTimeParameters: CTL_atlas_l3a_is_021426921.ctl (Type is String) stepDateTime: 2025-12-19T22:02:07.000000Z (Type is String) PGE(Type is Group) attributes ATBDDate: 12/04/2019 (Type is String) ATBDTitle: Algorithm Theoretical Basis Document (ATBD) For Land-Ice Along-Track Products Part 2: Land-ice H(t)/ATL11 (Type is String) ATBDVersion: N/A (Type is String) documentDate: Feb 2020 (Type is String) documentation: ATLAS Science Algorithm Software Design Description (SDD) - Volume 9 (atlas_l3a_is) (Type is String) processDescription: Computes surface heights for each beam, along and across-track slopes calculated for beam pairs. (Type is String) identifier: atlas_l3a_is (Type is String) softwareVersion: Version 5.1 (Type is String) softwareDate: Apr 8 2025 (Type is String) softwareTitle: ASAS L3A Icesheet PGE (Type is String) runTimeParameters: CTL_atlas_l3a_is_021426921.ctl (Type is String) stepDateTime: 2025-12-19T22:01:54.000000Z (Type is String) QA(Type is Group) attributes processDescription: QA processing is performed by an external utility on each granule produced by SIPS. The utility reads the granule, performs both generic and product-specific quality-assessment calculations, and writes a text-based quality assessment report. The name and creation data of this report are identified within the QADatasetIdentification metadata (Type is String) identifier: atl06_qa_util (Type is String) softwareVersion: Version 5.1 (Type is String) softwareDate: Apr 8 2025 (Type is String) softwareTitle: ATL06 QA Utility (Type is String) runTimeParameters: CTL_atlas_l3a_is_021426921.ctl (Type is String) stepDateTime: 2025-12-19T22:01:57.000000Z (Type is String) orbit_info(Type is Group) attributes description: Contains data that are common among all beams for the granule. These parameters are constants for a given granule. (Type is String) data_rate: These parameters are constant for a given granule. (Type is String) Dimensions: [ /orbit_info/crossing_time = 0..0 ] [ /orbit_info/sc_orient_time = 0..0 ] crossing_time[ /orbit_info/crossing_time= 0..0] (Type is Float64) attributes long_name: Ascending Node Crossing Time (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: POD/PPD (Type is String) contentType: referenceInformation (Type is String) description: The time, in seconds since the ATLAS SDP GPS Epoch, at which the ascending node crosses the equator. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) sc_orient_time[ /orbit_info/sc_orient_time= 0..0] (Type is Float64) attributes long_name: Time of Last Spacecraft Orientation Change (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: POD/PPD (Type is String) contentType: referenceInformation (Type is String) description: The time of the last spacecraft orientation change between forward, backward and transitional flight modes, expressed in seconds since the ATLAS SDP GPS Epoch. ICESat-2 is considered to be flying forward when the weak beams are leading the strong beams; and backward when the strong beams are leading the weak beams. ICESat-2 is considered to be in transition while it is maneuvering between the two orientations. Science quality is potentially degraded while in transition mode. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) cycle_number[ /orbit_info/crossing_time= 0..0] (Type is Int8) attributes long_name: Cycle Number (Type is String) units: counts (Type is String) source: POD/PPD (Type is String) valid_min: 0 (Type is Int8) valid_max: 50 (Type is Int8) contentType: referenceInformation (Type is String) description: Tracks the number of 91-day cycles in the mission, beginning with 01. A unique orbit number can be determined by subtracting 1 from the cycle_number, multiplying by 1387 and adding the rgt value. (Type is String) coordinates: crossing_time (Type is String) rgt[ /orbit_info/crossing_time= 0..0] (Type is Int16) attributes long_name: Reference Ground track (Type is String) units: counts (Type is String) source: POD/PPD (Type is String) valid_min: 1 (Type is Int16) valid_max: 1387 (Type is Int16) contentType: referenceInformation (Type is String) description: The reference ground track (RGT) is the track on the earth at which a specified unit vector within the observatory is pointed. Under nominal operating conditions, there will be no data collected along the RGT, as the RGT is spanned by GT2L and GT2R. During slews or off-pointing, it is possible that ground tracks may intersect the RGT. The ICESat-2 mission has 1387 RGTs. (Type is String) coordinates: crossing_time (Type is String) lan[ /orbit_info/crossing_time= 0..0] (Type is Float64) attributes long_name: Ascending Node Longitude (Type is String) units: degrees_east (Type is String) source: POD/PPD (Type is String) valid_min: -180. (Type is Float64) valid_max: 180. (Type is Float64) contentType: referenceInformation (Type is String) description: Longitude at the ascending node crossing. (Type is String) coordinates: crossing_time (Type is String) bounding_polygon_lat1[ 0..4] (Type is Float64) attributes long_name: Polygon1 Latitude (Type is String) units: degrees_north (Type is String) source: geo_poly (Type is String) valid_min: -90. (Type is Float64) valid_max: 90. (Type is Float64) contentType: auxiliaryInformation (Type is String) description: Latitude values for the first out of two possible bounding polygons (Type is String) orbit_number[ /orbit_info/crossing_time= 0..0] (Type is UInt16) attributes long_name: Orbit Number (Type is String) units: 1 (Type is String) source: POD/PPD (Type is String) valid_min: 1 (Type is UInt16) valid_max: 65000 (Type is UInt16) contentType: referenceInformation (Type is String) description: Unique identifying number for each planned ICESat-2 orbit. (Type is String) coordinates: crossing_time (Type is String) bounding_polygon_lon1[ 0..4] (Type is Float64) attributes long_name: Polygon1 Longitude (Type is String) units: degrees_east (Type is String) source: geo_poly (Type is String) valid_min: -180. (Type is Float64) valid_max: 180. (Type is Float64) contentType: auxiliaryInformation (Type is String) description: Longitude values for the first out of two possible bounding polygons (Type is String) sc_orient[ /orbit_info/sc_orient_time= 0..0] (Type is Int8) attributes long_name: Spacecraft Orientation (Type is String) units: 1 (Type is String) source: POD/PPD (Type is String) valid_min: 0 (Type is Int8) valid_max: 2 (Type is Int8) contentType: referenceInformation (Type is String) description: This parameter tracks the spacecraft orientation between forward, backward and transitional flight modes. ICESat-2 is considered to be flying forward when the weak beams are leading the strong beams; and backward when the strong beams are leading the weak beams. ICESat-2 is considered to be in transition while it is maneuvering between the two orientations. Science quality is potentially degraded while in transition mode. (Type is String) coordinates: sc_orient_time (Type is String) flag_meanings: backward forward transition (Type is String) flag_values: 0, 1, 2 (Type is Int8) gt3l(Type is Group) attributes description: Contains subgroups organized by Ground Track (gt1l, gt1r, gt2l, gt2r, gt3l and gt3r) (Type is String) atlas_pce: pce1 (Type is String) atlas_beam_type: weak (Type is String) groundtrack_id: gt3l (Type is String) atmosphere_profile: profile_3 (Type is String) atlas_spot_number: 2 (Type is String) sc_orientation: Forward (Type is String) land_ice_segments(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) description: The land_ice_height group contains the primary set of derived ATL06 products. This includes geolocation, height, and standard error and quality measures for each segment. This group is sparse, meaning that parameters are provided only for pairs of segments for which at least one beam has a valid surface-height measurement. (Type is String) data_rate: Data within this group are sparse. Data values are provided only for those ICESat-2 20m segments where at least one beam has a valid land ice height measurement. (Type is String) Dimensions: [ /gt3l/land_ice_segments/delta_time = 0..187 ] latitude[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float64) attributes long_name: Latitude (Type is String) standard_name: latitude (Type is String) units: degrees_north (Type is String) source: ATL06 ATBD - Top Level Fitting Routine (Type is String) valid_min: -90. (Type is Float64) valid_max: 90. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Latitude of segment center, WGS84, North=+, (Type is String) coordinates: delta_time longitude (Type is String) delta_time[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float64) attributes long_name: Elapsed GPS seconds (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: ATL06 ATBD - Top Level Fitting Routine (Type is String) contentType: referenceInformation (Type is String) description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: latitude longitude (Type is String) longitude[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float64) attributes long_name: Longitude (Type is String) standard_name: longitude (Type is String) units: degrees_east (Type is String) source: ATL06 ATBD - Top Level Fitting Routine (Type is String) valid_min: -180. (Type is Float64) valid_max: 180. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Longitude of segment center, , WGS84, East=+ (Type is String) coordinates: delta_time latitude (Type is String) sigma_geo_h[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Vertical Geolocation Error (Type is String) units: meters (Type is String) source: ATL06 ATBD - Segment Geolocation (Type is String) contentType: qualityInformation (Type is String) description: Total vertical geolocation error due to PPD and POD, including the effects of horizontal geolocation error on the segment vertical error. (Type is String) coordinates: delta_time latitude longitude (Type is String) h_li[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Land Ice height (Type is String) units: meters (Type is String) source: ATL06 ATBD - Top Level Fitting Routine (Type is String) contentType: physicalMeasurement (Type is String) description: Standard land-ice segment height determined by land ice algorithm, corrected for first-photon bias, representing the median- based height of the selected PEs (Type is String) coordinates: delta_time latitude longitude (Type is String) atl06_quality_summary[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes long_name: ATL06_Quality_Summary (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Top Level Fitting Routine (Type is String) valid_min: 0 (Type is Int8) valid_max: 1 (Type is Int8) contentType: qualityInformation (Type is String) description: The ATL06_quality_summary parameter indicates the best-quality subset of all ATL06 data. A zero in this parameter implies that no data-quality tests have found a problem with the segment, a one implies that some potential problem has been found. Users who select only segments with zero values for this flag can be relatively certain of obtaining high-quality data, but will likely miss a significant fraction of usable data, particularly in cloudy, rough, or low-surface-reflectance conditions. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: best_quality potential_problem (Type is String) flag_values: 0, 1 (Type is Int8) segment_id[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int32) attributes _FillValue: 0 (Type is Int32) long_name: Reference Point, m (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Top Level Fitting Routine (Type is String) contentType: referenceInformation (Type is String) description: Segment number, counting from the equator. Equal to the segment_id for the second of the two 20m ATL03 segments included in the 40m ATL06 segment (Type is String) coordinates: delta_time latitude longitude (Type is String) h_li_sigma[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Expected RMS segment misfit (Type is String) units: meters (Type is String) source: ATL06 ATBD - Top Level Fitting Routine (Type is String) contentType: qualityInformation (Type is String) description: Propagated error due to sampling error and FPB correction from the land ice algorithm (Type is String) coordinates: delta_time latitude longitude (Type is String) fpb_warning_flag[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes long_name: fpb_warning_flag (Type is String) units: 1 (Type is String) source: ATL06 ATBD - FPB Corrections (Type is String) valid_min: 0 (Type is Int8) valid_max: 1 (Type is Int8) contentType: qualityInformation (Type is String) description: To flag that segments have potentially erroneous FPB corrections, the ATL06 algorithm sets fpb_warning_flag to 1 if full_sat_fract is greater than 0.90 (strong beams) or greater than 0.40 (weak beams) for either of the two ATL03 20 m segments that are used as inputs to each ATL06 40 m segment. Otherwise, fpb_warning_flag is set to 0. (Type is String) coordinates: latitude longitude delta_time (Type is String) flag_meanings: best_quality potential_problem (Type is String) flag_values: 0, 1 (Type is Int8) fit_statistics(Type is Group) attributes description: The fit_statistics subgroup contains a variety of parameters that might indicate the quality of the fitted segment data. Data in this group are sparse, with dimensions matching the land_ice_height group. (Type is String) data_rate: Data within this group are stored at the land_ice_height segment rate. (Type is String) h_mean[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Height Mean (Type is String) units: meters (Type is String) source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String) contentType: modelResult (Type is String) description: Mean surface height, not corrected for first-photon bias or pulse truncation. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) signal_selection_source[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes long_name: Signal Selection Source (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Signal Selection based on ATL03 flags (Type is String) valid_min: 0 (Type is Int8) valid_max: 3 (Type is Int8) contentType: qualityInformation (Type is String) description: Indicates the last algorithm attempted to select the signal for ATL06 fitting. 0=Signal selection succeeded using ATL03 detected PE; 1=Signal selection failed using ATL03 detected PE but succeeded using all flagged ATL03 PE; 2=Signal selection failed using all flagged ATL03 PE, but succeeded using the backup algorithm; 3=All signal-finding strategies failed. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: succeeded_using_pe succeeded_using_flagged_pe succeeded_using_backup failed (Type is String) flag_values: 0, 1, 2, 3 (Type is Int8) snr[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: SNR (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Iterative Least Squares Fitting Routine (Type is String) contentType: physicalMeasurement (Type is String) description: Signal-to-noise ratio in the final refined window (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_robust_sprd[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Robust Spread (Type is String) units: meters (Type is String) source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String) contentType: referenceInformation (Type is String) description: RDE of misfit between PE heights and the along-track segment fit. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) n_seg_pulses[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes units: counts (Type is String) _FillValue: 3.402823466e+38 (Type is Float32) long_name: Number potential segment pulses (Type is String) source: ATL06 ATBD - Top-Level Fitting Routine (Type is String) contentType: referenceInformation (Type is String) description: The number of pulses potentially included in the segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) dh_fit_dx_sigma[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Sigma of Along Track Slope (Type is String) units: meters/meters (Type is String) source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String) contentType: qualityInformation (Type is String) description: Propagated error in the along-track segment slope (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) snr_significance[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: SNR Significance (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Top-Level Fitting Routine (Type is String) contentType: physicalMeasurement (Type is String) description: Probability that signal-finding routine would converge to at least the observed SNR for a random-noise input. Small values indicate a small likelihood of a surface-detection blunder. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_expected_rms[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Expected RMS misfit (Type is String) units: meters (Type is String) source: ATL06 ATBD - Iterative ground-window refinement (Type is String) contentType: qualityInformation (Type is String) description: Expected RMS misfit between PE heights and along-track segment fit (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) dh_fit_dy[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Across Track Slope (Type is String) units: meters/meters (Type is String) source: ATL06 ATBD - Top-Level Fitting Routine (Type is String) contentType: physicalMeasurement (Type is String) description: Across track slope from segment fits to weak and strong beam; the same slope is reported for both laser beams in each pair (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) sigma_h_mean[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Height Error (Type is String) units: meters (Type is String) source: ATL06 ATBD - Propagated Height Errors (Type is String) contentType: qualityInformation (Type is String) description: Propagated height error due to PE-height sampling error for height from the along-track fit, not including geolocation-induced error (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_rms_misfit[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: RMS Misfit (Type is String) units: meters (Type is String) source: ATL06 ATBD -Iterative Least-Squares Fitting Routine (Type is String) contentType: qualityInformation (Type is String) description: RMS misfit between PE heights and along- track segment fit (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) signal_selection_source_status[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes long_name: Signal Selection Source Status (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Signal Selection based on ATL03 flags (Type is String) valid_min: 0 (Type is Int8) valid_max: 4 (Type is Int8) contentType: qualityInformation (Type is String) description: Indicates the status of the last signal selection algorithm attempted (see signal_selection_source). The definition of flag is different for each source and are defined in each of the signal_selection_status flags. (See Land Ice ATBD Table 3-2). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) dh_fit_dx[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Along Track Slope (Type is String) units: meters/meters (Type is String) source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String) contentType: physicalMeasurement (Type is String) description: Along-track slope from along-track segment fit (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) n_fit_photons[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int32) attributes _FillValue: 2147483647 (Type is Int32) long_name: Number of Photons in Fit (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String) contentType: physicalMeasurement (Type is String) description: Number of PEs used in determining h_li, after editing (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) w_surface_window_final[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Surface Window Width (Type is String) units: meters (Type is String) source: ATL06 ATBD - Top-Level Fitting Routine (Type is String) contentType: physicalMeasurement (Type is String) description: Width of the surface window, top to bottom (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) ground_track(Type is Group) attributes description: The ground_track group contains parameters describing the GT and RGT for each land ice segment, as well as angular information about the beams. (Type is String) data_rate: Data within this group are stored at the land_ice_height segment rate. (Type is String) sigma_geo_at[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Along Track Geolocation Error (Type is String) units: meters (Type is String) source: ATL06 ATBD - Segment Geolocation (Type is String) contentType: qualityInformation (Type is String) description: Along-track component of the geolocation error. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) ref_azimuth[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Azimuth (Type is String) units: degrees (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: The direction, eastwards from north, of the laser beam vector as seen by an observer at the laser ground spot viewing toward the spacecraft (i.e., the vector from the ground to the spacecraft). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) sigma_geo_r[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Radial Orbit Error (Type is String) units: meters (Type is String) source: ATL06 ATBD - Segment Geolocation (Type is String) contentType: qualityInformation (Type is String) description: Radial orbit component of the geolocation error. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) seg_azimuth[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Segment Azimuth (Type is String) units: degrees (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Azimuth of the pair-track, east of local north. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) sigma_geo_xt[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Across Track Geolocation Error (Type is String) units: meters (Type is String) source: ATL06 ATBD - Segment Geolocation (Type is String) contentType: qualityInformation (Type is String) description: Across-track component of the geolocation error. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) ref_coelv[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Co-elevation (Type is String) units: degrees (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Coelevation (CE) is direction from vertical of the laser beam as seen by an observer located at the laser ground spot. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) x_atc[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float64) attributes _FillValue: 1.7976931348623157e+308 (Type is Float64) long_name: X Along Track (Type is String) units: meters (Type is String) source: ATL06 ATBD - Local Coordinate Systems (Type is String) contentType: referenceInformation (Type is String) description: The along-track x-coordinate of the segment, measured parallel to the RGT, measured from the ascending node of the equatorial crossing of a given RGT. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) y_atc[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Y Along Track (Type is String) units: meters (Type is String) source: ATL06 ATBD - Local Coordinate Systems (Type is String) contentType: referenceInformation (Type is String) description: Along-track y coordinate of the segment, relative to the RGT, measured along the perpendicular to the RGT, positive to the right of the RGT. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) dem(Type is Group) attributes description: Contains reference DEM and geoid heights. (Type is String) data_rate: Data within this group are stored at the land_ice segment rate. (Type is String) dem_flag[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes long_name: DEM Source Flag (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) valid_min: 0 (Type is Int8) valid_max: 4 (Type is Int8) contentType: referenceInformation (Type is String) description: Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=Global, 3=MSS, 4=Antarctic. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: none arctic global mss antarctic (Type is String) flag_values: 0, 1, 2, 3, 4 (Type is Int8) geoid_free2mean[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Geoid Free-to-Mean conversion (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: modelResult (Type is String) description: Additive value to convert geoid heights from the tide-free system to the mean-tide system. (Add to geoid to get the geoid heights in the mean-tide system.) (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) dem_h[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: DEM Height (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Height of the DEM, interpolated by cubic-spline interpolation in the DEM coordinate system to the PE location. (Best available DEM value in priority of Arctic/Antarctic/Global/MSS) (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) geoid_h[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Geoid Height (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Geoid height above WGS-84 reference ellipsoid (range -107 to 86m) in the tide-free system. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) geophysical(Type is Group) attributes description: The sun_and_clouds group contains parameters related to solar background and parameters indicative of the presence or absence of clouds. (Type is String) data_rate: Data within this group are stored at the land_ice_height segment rate. (Type is String) msw_flag[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: Multiple Scattering Warning Flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: -1 (Type is Int8) valid_max: 5 (Type is Int8) contentType: referenceInformation (Type is String) description: Multiple Scattering warning flag. The multiple scattering warning flag (ATL09 parameter msw_flag) has values from -1 to 5 where zero means no multiple scattering and 5 the greatest. If no layers were detected, then msw_flag = 0. If blowing snow is detected and its estimated optical depth is greater than or equal to 0.5, then msw_flag = 5. If the blowing snow optical depth is less than 0.5, then msw_flag = 4. If no blowing snow is detected but there are cloud or aerosol layers detected, the msw_flag assumes values of 1 to 3 based on the height of the bottom of the lowest layer: < 1 km, msw_flag = 3; 1-3 km, msw_flag = 2; > 3km, msw_flag = 1. A value of -1 indicates that the signal to noise of the data was too low to reliably ascertain the presence of cloud or blowing snow. We expect values of -1 to occur only during daylight. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: cannot_determine no_layers layer_gt_3km layer_between_1_and_3_km layer_lt_1km blow_snow_od_lt_0.5 blow_snow_od_gt_0.5 (Type is String) flag_values: -1, 0, 1, 2, 3, 4, 5 (Type is Int8) layer_flag[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes units: 1 (Type is String) source: ATL09 (Type is String) _FillValue: 127 (Type is Int8) long_name: Consolidated cloud flag (Type is String) valid_min: 0 (Type is Int8) valid_max: 1 (Type is Int8) contentType: referenceInformation (Type is String) description: This flag is a combination of multiple flags (cloud_flag_atm, cloud_flag_asr, and bsnow_con) and takes daytime/nighttime into consideration. A value of 1 means clouds or blowing snow are likely present. A value of 0 indicates the likely absence of clouds or blowing snow. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: likely_clear likely_cloudy (Type is String) flag_values: 0, 1 (Type is Int8) bsnow_conf[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: Blowing Snow confidence (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: referenceInformation (Type is String) description: Confidence flag for presence of blowing snow (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) bsnow_h[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Blowing Snow Layer Top Height (Type is String) units: meters (Type is String) source: ATL09 (Type is String) contentType: referenceInformation (Type is String) description: Blowing snow layer top height (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) tide_ocean[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Ocean Tide (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Ocean Tides including diurnal and semi-diurnal (harmonic analysis), and longer period tides (dynamic and self-consistent equilibrium). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) tide_earth[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Earth Tide (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Solid earth tides in the tide-free system. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) solar_azimuth[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: solar azimuth (Type is String) units: degrees_east (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) r_eff[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Effective uncorrected reflectance (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Top-Level Fitting Routine (Type is String) contentType: referenceInformation (Type is String) description: Effective reflectance, uncorrected for atmospheric effects. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) dac[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Dynamic Atmosphere Correction (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) tide_load[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Load Tide (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Load Tide - Local displacement due to Ocean Loading (-6 to 0 cm). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) tide_earth_free2mean[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Earth Tide Free-to-Mean conversion (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Additive value to convert solid earth tide from the tide-free system to the mean tide system. (Add to tide_earth to get solid earth tides in the mean-tide system.) (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) bsnow_od[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Blowing snow OD (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: modelResult (Type is String) description: Optical thickness of blowing snow layer. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) tide_equilibrium[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Equilibrium Tide (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Long period equilibrium tide self-consistent with the ocean tide model (+-0.04m). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) cloud_flg_atm[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: Cloud Flag ATM (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 10 (Type is Int8) contentType: referenceInformation (Type is String) description: Number of layers found from the backscatter profile using the DDA layer finder. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) solar_elevation[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: solar elevation (Type is String) units: degrees (Type is String) source: ATL03 (Type is String) valid_min: -90. (Type is Float32) valid_max: 90. (Type is Float32) contentType: referenceInformation (Type is String) description: Solar Angle above or below the plane tangent to the ellipsoid surface at the laser spot. Positive values mean the sun is above the horizon, while negative values mean it is below the horizon. The effect of atmospheric refraction is not included. This is a low-precision value, with approximately TBD degree accuracy. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) tide_pole[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Solid Earth Pole Tide (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Solid Earth Pole Tide -Rotational deformation due to polar motion (-1.5 to 1.5 cm). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) e_bckgrd[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Expected background count rate (Type is String) units: hz (Type is String) source: ATL06 ATBD - Background PE Rate (Type is String) contentType: referenceInformation (Type is String) description: Expected background count rate based on sun angle, surface slope, for unit surface reflectance (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) cloud_flg_asr[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: Cloud Flag ASR (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 5 (Type is Int8) contentType: referenceInformation (Type is String) description: Cloud flag (probability) from apparent surface reflectance. 0=clear with high confidence; 1=clear with medium confidence; 2=clear with low confidence; 3=cloudy with low confidence; 4=cloudy with medium confidence; 5=cloudy with high confidence (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: clear_with_high_confidence clear_with_medium_confidence clear_with_low_confidence cloudy_with_low_confidence cloudy_with_medium_confidence cloudy_with_high_confidence (Type is String) flag_values: 0, 1, 2, 3, 4, 5 (Type is Int8) bckgrd[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Background count rate (Type is String) units: hz (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Background count rate, derived from the ATL03 50-shot-average, interpolated to the segment center. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) neutat_delay_total[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Total Neutral Atmospheric Delay (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Total neutral atmosphere delay correction (wet+dry). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) bias_correction(Type is Group) attributes description: The bias_correction group contains information about the estimated first-photon bias, and the transmit-pulse-shape bias. (Type is String) data_rate: Data within this group are stored at the land_ice segment rate. (Type is String) fpb_mean_corr_sigma[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes units: meters (Type is String) _FillValue: 3.402823466e+38 (Type is Float32) long_name: fpb mean corr sigma (Type is String) source: ATL06 ATBD - First-Photon Bias Correction (Type is String) contentType: qualityInformation (Type is String) description: Estimated error in fpb_mean_corr (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) fpb_med_corr_sigma[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: fpb median corr sigma (Type is String) units: meters (Type is String) source: ATL06 ATBD - First-Photon Bias Correction (Type is String) contentType: qualityInformation (Type is String) description: Estimated error in fpb_med_corr (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) fpb_mean_corr[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: first photon bias mean correction (Type is String) units: meters (Type is String) source: ATL06 ATBD - First-Photon Bias Correction (Type is String) contentType: qualityInformation (Type is String) description: Estimated first-photon bias (fpb) correction to mean segment height (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) med_r_fit[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mean median residual (Type is String) units: meters (Type is String) source: ATL06 ATBD - Top-Level Fitting Routine (Type is String) contentType: qualityInformation (Type is String) description: Difference between uncorrected mean and median of linear fit residuals (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) fpb_med_corr[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: fpb median corr (Type is String) units: meters (Type is String) source: ATL06 ATBD - First-Photon Bias Correction (Type is String) contentType: qualityInformation (Type is String) description: First-photon-bias correction giving the difference between the mean segment height and the corrected median height (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) tx_mean_corr[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: tx shape mean correction (Type is String) units: meters (Type is String) source: ATL06 ATBD - Transmit-pulse shape correction (Type is String) contentType: qualityInformation (Type is String) description: Estimate of the difference between the mean of the full-waveform transmit-pulse and the mean of a broadened, truncated waveform consistent with the received pulse (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) fpb_n_corr[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: fpb number photons corr (Type is String) units: counts (Type is String) source: ATL06 ATBD - First-Photon Bias Correction (Type is String) contentType: qualityInformation (Type is String) description: Estimated window photon count after first-photon-bias correction (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) tx_med_corr[ /gt3l/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: tx shape median correction (Type is String) units: meters (Type is String) source: ATL06 ATBD - Transmit-pulse shape correction (Type is String) contentType: qualityInformation (Type is String) description: Estimate of the difference between the median of the full-waveform transmit-pulse mean and the median of a broadened, truncated waveform consistent with the received pulse (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) residual_histogram(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) data_rate: Data within this group are stored at the 200-meter along-track rate. (Type is String) description: This group contains histograms of the residuals between PE heights and the least-squares fit segment heights, at 200-meter along-track resolution. (Type is String) Dimensions: [ /gt3l/residual_histogram/delta_time = 0..15 ] [ /gt3l/residual_histogram/bin_top_h = 0..747 ] [ /gt3l/residual_histogram/ds_segment_id = 0..9 ] ds_segment_id[ /gt3l/residual_histogram/ds_segment_id= 0..9] (Type is Int8) attributes long_name: Segment ID Index (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) valid_min: 1 (Type is Int8) valid_max: 10 (Type is Int8) contentType: auxiliaryInformation (Type is String) description: Relative index of each segment_id used in the derivation of the histogram. (Type is String) lat_mean[ /gt3l/residual_histogram/delta_time= 0..15] (Type is Float64) attributes long_name: Latitude Mean (Type is String) standard_name: latitude (Type is String) units: degrees_north (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) valid_min: -90. (Type is Float64) valid_max: 90. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Mean latitude of the segments included in the histogram (Type is String) coordinates: delta_time lon_mean (Type is String) lon_mean[ /gt3l/residual_histogram/delta_time= 0..15] (Type is Float64) attributes long_name: Longitude Mean (Type is String) standard_name: longitude (Type is String) units: degrees_east (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) valid_min: -180. (Type is Float64) valid_max: 180. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Mean longitude of the segments included in the histogram (Type is String) coordinates: delta_time lat_mean (Type is String) delta_time[ /gt3l/residual_histogram/delta_time= 0..15] (Type is Float64) attributes long_name: Elapsed GPS seconds (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) contentType: referenceInformation (Type is String) description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: lat_mean lon_mean (Type is String) bin_top_h[ /gt3l/residual_histogram/bin_top_h= 0..747] (Type is Float32) attributes long_name: Bin Top Height (Type is String) units: meters (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) contentType: physicalMeasurement (Type is String) description: Height of the top of each histogram bin, listed in increasing order. The bottom of each bin is equal to the top of the next- lowest bin. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) count[ /gt3l/residual_histogram/delta_time= 0..15] [ /gt3l/residual_histogram/bin_top_h= 0..747] (Type is Int32) attributes _FillValue: 2147483647 (Type is Int32) long_name: Bin Counts (Type is String) units: counts (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) contentType: physicalMeasurement (Type is String) description: Residual count falling with each histogram bin. The top height of each histogram bin may be found in the bin_top_h dataset. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) pulse_count[ /gt3l/residual_histogram/delta_time= 0..15] (Type is Float32) attributes long_name: Number of Histogram Segment Pulses (Type is String) units: counts (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) contentType: physicalMeasurement (Type is String) description: Number of pulses potentially included in the histogram (pulses are counted if they are in the central 20 m of each segment, even if no PE from the pulse are selected). (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) x_atc_mean[ /gt3l/residual_histogram/delta_time= 0..15] (Type is Float64) attributes long_name: Along Track Coordinate Mean (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) contentType: physicalMeasurement (Type is String) description: Mean along-track coordinate of the segments included in the histogram. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) segment_id_list[ /gt3l/residual_histogram/delta_time= 0..15] [ /gt3l/residual_histogram/ds_segment_id= 0..9] (Type is Int32) attributes long_name: Segment ID List (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) contentType: referenceInformation (Type is String) description: Segments ids included in each column of the histogram (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) _FillValue: 2147483647 (Type is Int32) bckgrd_per_m[ /gt3l/residual_histogram/delta_time= 0..15] (Type is Float32) attributes long_name: Expected background PEs (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) contentType: physicalMeasurement (Type is String) description: Number of background PE expected for each vertical meter of the histogram based on the observed background rate (bckgrd). (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) segment_quality(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) data_rate: Data within this group are stored at the ICESat-2 20m segment rate. (Type is String) description: The segment_quality group contains a dense record (i.e. for every possible segment in the granule) of the success or failure of the surface-finding strategies, and gives the locations of the reference points on the RPTs. For segments with adequate data quality (i.e. with more than 10 PE) it also contains offsets into the data structures for the other groups that allow each segment to be efficiently located within the file. (Type is String) Dimensions: [ /gt3l/segment_quality/delta_time = 0..201 ] reference_pt_lat[ /gt3l/segment_quality/delta_time= 0..201] (Type is Float64) attributes long_name: Latitude (Type is String) units: degrees_north (Type is String) source: ATL06 ATBD - segment_quality group (Type is String) valid_min: -90. (Type is Float64) valid_max: 90. (Type is Float64) contentType: referenceInformation (Type is String) description: Latitude of the reference segment location on the RPT (Type is String) coordinates: delta_time reference_pt_lon (Type is String) standard_name: latitude (Type is String) reference_pt_lon[ /gt3l/segment_quality/delta_time= 0..201] (Type is Float64) attributes long_name: Longitude (Type is String) units: degrees_east (Type is String) source: ATL06 ATBD - segment_quality group (Type is String) valid_min: -180. (Type is Float64) valid_max: 180. (Type is Float64) contentType: referenceInformation (Type is String) description: Longitude of the reference segment location on the RPT (Type is String) coordinates: delta_time reference_pt_lat (Type is String) standard_name: longitude (Type is String) delta_time[ /gt3l/segment_quality/delta_time= 0..201] (Type is Float64) attributes long_name: Elapsed GPS seconds (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: ATL06 ATBD - segment_quality group (Type is String) contentType: referenceInformation (Type is String) description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: reference_pt_lat reference_pt_lon (Type is String) record_number[ /gt3l/segment_quality/delta_time= 0..201] (Type is Int32) attributes long_name: Land Ice Height Index (Type is String) units: 1 (Type is String) source: ATL06 ATBD - segment_quality group (Type is String) contentType: referenceInformation (Type is String) description: For those segments that have adequate signal strength, this parameter gives the record for the pair within the other groups in the granule. (Type is String) coordinates: delta_time reference_pt_lat reference_pt_lon (Type is String) signal_selection_source[ /gt3l/segment_quality/delta_time= 0..201] (Type is Int8) attributes long_name: Signal Selection Source (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Signal selection base on ATL03 flags (Type is String) valid_min: 0 (Type is Int8) valid_max: 3 (Type is Int8) contentType: qualityInformation (Type is String) description: Indicates the last algorithm attempted to select the signal for ATL06 fitting. 0=Signal selection succeeded using ATL03 detected PE; 1=Signal selection failed using ATL03 detected PE but succeeded using all flagged ATL03 PE; 3=All signal-finding strategies failed. (Type is String) coordinates: delta_time reference_pt_lat reference_pt_lon (Type is String) flag_meanings: succeeded_using_pe succeeded_using_flagged_pe failed (Type is String) flag_values: 0, 1, 3 (Type is Int8) segment_id[ /gt3l/segment_quality/delta_time= 0..201] (Type is Int32) attributes long_name: Reference Point, m (Type is String) units: 1 (Type is String) source: ATL06 ATBD - segment_quality group (Type is String) contentType: referenceInformation (Type is String) description: Segment number corresponding to the second of two ATL03 segments in the ATL06 segment, counted from the RGT equator crossing (Type is String) coordinates: delta_time reference_pt_lat reference_pt_lon (Type is String) signal_selection_status(Type is Group) attributes description: The signal selection status subgroup contains the success or failure for each surface-finding strategies (Type is String) data_rate: Data within this group are stored at the ICESat-2 20m segment rate. (Type is String) signal_selection_status_all[ /gt3l/segment_quality/delta_time= 0..201] (Type is Int8) attributes units: 1 (Type is String) long_name: Signal Selection Status Flag (Type is String) source: ATL06 ATBD - Signal selection base on ATL03 flags (Type is String) valid_min: 0 (Type is Int8) valid_max: 3 (Type is Int8) contentType: qualityInformation (Type is String) description: Indicates confidence of the signal-selection algorithm using all ATL03-flagged PEs. 0=Signal selection succeeded using all ATL03-flagged PEs (or algorithm not attempted); 1=Signal selection using all ATL03-flagged PEs failed the 20-meter-spread test; 2=Signal selection using all ATL03-flagged PEs failed the 10-photon-count test; 3=Signal selection using all ATL03-flagged PEs failed both tests (Type is String) coordinates: ../delta_time ../reference_pt_lat ../reference_pt_lon (Type is String) flag_meanings: succeeded failed_20 failed_10 failed_both (Type is String) flag_values: 0, 1, 2, 3 (Type is Int8) signal_selection_status_confident[ /gt3l/segment_quality/delta_time= 0..201] (Type is Int8) attributes units: 1 (Type is String) long_name: Signal Selection Confident Flag (Type is String) source: ATL06 ATBD - Signal selection base on ATL03 flags (Type is String) valid_min: 0 (Type is Int8) valid_max: 3 (Type is Int8) contentType: qualityInformation (Type is String) description: Indicates confidence of the signal-selection algorithm using low or better PEs. 0=Signal selection succeeded using ATL03 low-or-better confidence PEs; 1=Signal selection using ATL03 low-or-better confidence PEs failed the 20-meter-spread test; 2=Signal selection using ATL03 low-or-better confidence PEs failed the 10-photon-count test; 3=Signal selection using ATL03 low-or-better confidence PEs failed both tests (Type is String) coordinates: ../delta_time ../reference_pt_lat ../reference_pt_lon (Type is String) flag_meanings: succeeded failed_20 failed_10 failed_both (Type is String) flag_values: 0, 1, 2, 3 (Type is Int8) gt3r(Type is Group) attributes description: Contains subgroups organized by Ground Track (gt1l, gt1r, gt2l, gt2r, gt3l and gt3r) (Type is String) atlas_pce: pce1 (Type is String) atlas_beam_type: strong (Type is String) groundtrack_id: gt3r (Type is String) atmosphere_profile: profile_3 (Type is String) atlas_spot_number: 1 (Type is String) sc_orientation: Forward (Type is String) land_ice_segments(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) description: The land_ice_height group contains the primary set of derived ATL06 products. This includes geolocation, height, and standard error and quality measures for each segment. This group is sparse, meaning that parameters are provided only for pairs of segments for which at least one beam has a valid surface-height measurement. (Type is String) data_rate: Data within this group are sparse. Data values are provided only for those ICESat-2 20m segments where at least one beam has a valid land ice height measurement. (Type is String) Dimensions: [ /gt3r/land_ice_segments/delta_time = 0..187 ] latitude[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float64) attributes long_name: Latitude (Type is String) standard_name: latitude (Type is String) units: degrees_north (Type is String) source: ATL06 ATBD - Top Level Fitting Routine (Type is String) valid_min: -90. (Type is Float64) valid_max: 90. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Latitude of segment center, WGS84, North=+, (Type is String) coordinates: delta_time longitude (Type is String) delta_time[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float64) attributes long_name: Elapsed GPS seconds (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: ATL06 ATBD - Top Level Fitting Routine (Type is String) contentType: referenceInformation (Type is String) description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: latitude longitude (Type is String) longitude[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float64) attributes long_name: Longitude (Type is String) standard_name: longitude (Type is String) units: degrees_east (Type is String) source: ATL06 ATBD - Top Level Fitting Routine (Type is String) valid_min: -180. (Type is Float64) valid_max: 180. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Longitude of segment center, , WGS84, East=+ (Type is String) coordinates: delta_time latitude (Type is String) sigma_geo_h[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Vertical Geolocation Error (Type is String) units: meters (Type is String) source: ATL06 ATBD - Segment Geolocation (Type is String) contentType: qualityInformation (Type is String) description: Total vertical geolocation error due to PPD and POD, including the effects of horizontal geolocation error on the segment vertical error. (Type is String) coordinates: delta_time latitude longitude (Type is String) h_li[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Land Ice height (Type is String) units: meters (Type is String) source: ATL06 ATBD - Top Level Fitting Routine (Type is String) contentType: physicalMeasurement (Type is String) description: Standard land-ice segment height determined by land ice algorithm, corrected for first-photon bias, representing the median- based height of the selected PEs (Type is String) coordinates: delta_time latitude longitude (Type is String) atl06_quality_summary[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes long_name: ATL06_Quality_Summary (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Top Level Fitting Routine (Type is String) valid_min: 0 (Type is Int8) valid_max: 1 (Type is Int8) contentType: qualityInformation (Type is String) description: The ATL06_quality_summary parameter indicates the best-quality subset of all ATL06 data. A zero in this parameter implies that no data-quality tests have found a problem with the segment, a one implies that some potential problem has been found. Users who select only segments with zero values for this flag can be relatively certain of obtaining high-quality data, but will likely miss a significant fraction of usable data, particularly in cloudy, rough, or low-surface-reflectance conditions. (Type is String) coordinates: delta_time latitude longitude (Type is String) flag_meanings: best_quality potential_problem (Type is String) flag_values: 0, 1 (Type is Int8) segment_id[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int32) attributes _FillValue: 0 (Type is Int32) long_name: Reference Point, m (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Top Level Fitting Routine (Type is String) contentType: referenceInformation (Type is String) description: Segment number, counting from the equator. Equal to the segment_id for the second of the two 20m ATL03 segments included in the 40m ATL06 segment (Type is String) coordinates: delta_time latitude longitude (Type is String) h_li_sigma[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Expected RMS segment misfit (Type is String) units: meters (Type is String) source: ATL06 ATBD - Top Level Fitting Routine (Type is String) contentType: qualityInformation (Type is String) description: Propagated error due to sampling error and FPB correction from the land ice algorithm (Type is String) coordinates: delta_time latitude longitude (Type is String) fpb_warning_flag[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes long_name: fpb_warning_flag (Type is String) units: 1 (Type is String) source: ATL06 ATBD - FPB Corrections (Type is String) valid_min: 0 (Type is Int8) valid_max: 1 (Type is Int8) contentType: qualityInformation (Type is String) description: To flag that segments have potentially erroneous FPB corrections, the ATL06 algorithm sets fpb_warning_flag to 1 if full_sat_fract is greater than 0.90 (strong beams) or greater than 0.40 (weak beams) for either of the two ATL03 20 m segments that are used as inputs to each ATL06 40 m segment. Otherwise, fpb_warning_flag is set to 0. (Type is String) coordinates: latitude longitude delta_time (Type is String) flag_meanings: best_quality potential_problem (Type is String) flag_values: 0, 1 (Type is Int8) fit_statistics(Type is Group) attributes description: The fit_statistics subgroup contains a variety of parameters that might indicate the quality of the fitted segment data. Data in this group are sparse, with dimensions matching the land_ice_height group. (Type is String) data_rate: Data within this group are stored at the land_ice_height segment rate. (Type is String) h_mean[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Height Mean (Type is String) units: meters (Type is String) source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String) contentType: modelResult (Type is String) description: Mean surface height, not corrected for first-photon bias or pulse truncation. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) signal_selection_source[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes long_name: Signal Selection Source (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Signal Selection based on ATL03 flags (Type is String) valid_min: 0 (Type is Int8) valid_max: 3 (Type is Int8) contentType: qualityInformation (Type is String) description: Indicates the last algorithm attempted to select the signal for ATL06 fitting. 0=Signal selection succeeded using ATL03 detected PE; 1=Signal selection failed using ATL03 detected PE but succeeded using all flagged ATL03 PE; 2=Signal selection failed using all flagged ATL03 PE, but succeeded using the backup algorithm; 3=All signal-finding strategies failed. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: succeeded_using_pe succeeded_using_flagged_pe succeeded_using_backup failed (Type is String) flag_values: 0, 1, 2, 3 (Type is Int8) snr[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: SNR (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Iterative Least Squares Fitting Routine (Type is String) contentType: physicalMeasurement (Type is String) description: Signal-to-noise ratio in the final refined window (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_robust_sprd[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Robust Spread (Type is String) units: meters (Type is String) source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String) contentType: referenceInformation (Type is String) description: RDE of misfit between PE heights and the along-track segment fit. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) n_seg_pulses[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes units: counts (Type is String) _FillValue: 3.402823466e+38 (Type is Float32) long_name: Number potential segment pulses (Type is String) source: ATL06 ATBD - Top-Level Fitting Routine (Type is String) contentType: referenceInformation (Type is String) description: The number of pulses potentially included in the segment (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) dh_fit_dx_sigma[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Sigma of Along Track Slope (Type is String) units: meters/meters (Type is String) source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String) contentType: qualityInformation (Type is String) description: Propagated error in the along-track segment slope (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) snr_significance[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: SNR Significance (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Top-Level Fitting Routine (Type is String) contentType: physicalMeasurement (Type is String) description: Probability that signal-finding routine would converge to at least the observed SNR for a random-noise input. Small values indicate a small likelihood of a surface-detection blunder. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_expected_rms[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Expected RMS misfit (Type is String) units: meters (Type is String) source: ATL06 ATBD - Iterative ground-window refinement (Type is String) contentType: qualityInformation (Type is String) description: Expected RMS misfit between PE heights and along-track segment fit (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) dh_fit_dy[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Across Track Slope (Type is String) units: meters/meters (Type is String) source: ATL06 ATBD - Top-Level Fitting Routine (Type is String) contentType: physicalMeasurement (Type is String) description: Across track slope from segment fits to weak and strong beam; the same slope is reported for both laser beams in each pair (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) sigma_h_mean[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Height Error (Type is String) units: meters (Type is String) source: ATL06 ATBD - Propagated Height Errors (Type is String) contentType: qualityInformation (Type is String) description: Propagated height error due to PE-height sampling error for height from the along-track fit, not including geolocation-induced error (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) h_rms_misfit[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: RMS Misfit (Type is String) units: meters (Type is String) source: ATL06 ATBD -Iterative Least-Squares Fitting Routine (Type is String) contentType: qualityInformation (Type is String) description: RMS misfit between PE heights and along- track segment fit (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) signal_selection_source_status[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes long_name: Signal Selection Source Status (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Signal Selection based on ATL03 flags (Type is String) valid_min: 0 (Type is Int8) valid_max: 4 (Type is Int8) contentType: qualityInformation (Type is String) description: Indicates the status of the last signal selection algorithm attempted (see signal_selection_source). The definition of flag is different for each source and are defined in each of the signal_selection_status flags. (See Land Ice ATBD Table 3-2). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) dh_fit_dx[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Along Track Slope (Type is String) units: meters/meters (Type is String) source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String) contentType: physicalMeasurement (Type is String) description: Along-track slope from along-track segment fit (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) n_fit_photons[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int32) attributes _FillValue: 2147483647 (Type is Int32) long_name: Number of Photons in Fit (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Iterative Least-Squares Fitting Routine (Type is String) contentType: physicalMeasurement (Type is String) description: Number of PEs used in determining h_li, after editing (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) w_surface_window_final[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Surface Window Width (Type is String) units: meters (Type is String) source: ATL06 ATBD - Top-Level Fitting Routine (Type is String) contentType: physicalMeasurement (Type is String) description: Width of the surface window, top to bottom (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) ground_track(Type is Group) attributes description: The ground_track group contains parameters describing the GT and RGT for each land ice segment, as well as angular information about the beams. (Type is String) data_rate: Data within this group are stored at the land_ice_height segment rate. (Type is String) sigma_geo_at[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Along Track Geolocation Error (Type is String) units: meters (Type is String) source: ATL06 ATBD - Segment Geolocation (Type is String) contentType: qualityInformation (Type is String) description: Along-track component of the geolocation error. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) ref_coelv[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Co-elevation (Type is String) units: degrees (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Coelevation (CE) is direction from vertical of the laser beam as seen by an observer located at the laser ground spot. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) sigma_geo_r[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Radial Orbit Error (Type is String) units: meters (Type is String) source: ATL06 ATBD - Segment Geolocation (Type is String) contentType: qualityInformation (Type is String) description: Radial orbit component of the geolocation error. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) seg_azimuth[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Segment Azimuth (Type is String) units: degrees (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Azimuth of the pair-track, east of local north. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) sigma_geo_xt[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Across Track Geolocation Error (Type is String) units: meters (Type is String) source: ATL06 ATBD - Segment Geolocation (Type is String) contentType: qualityInformation (Type is String) description: Across-track component of the geolocation error. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) ref_azimuth[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Azimuth (Type is String) units: degrees (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: The direction, eastwards from north, of the laser beam vector as seen by an observer at the laser ground spot viewing toward the spacecraft (i.e., the vector from the ground to the spacecraft). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) x_atc[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float64) attributes _FillValue: 1.7976931348623157e+308 (Type is Float64) long_name: X Along Track (Type is String) units: meters (Type is String) source: ATL06 ATBD - Local Coordinate Systems (Type is String) contentType: referenceInformation (Type is String) description: The along-track x-coordinate of the segment, measured parallel to the RGT, measured from the ascending node of the equatorial crossing of a given RGT. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) y_atc[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Y Along Track (Type is String) units: meters (Type is String) source: ATL06 ATBD - Local Coordinate Systems (Type is String) contentType: referenceInformation (Type is String) description: Along-track y coordinate of the segment, relative to the RGT, measured along the perpendicular to the RGT, positive to the right of the RGT. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) dem(Type is Group) attributes description: Contains reference DEM and geoid heights. (Type is String) data_rate: Data within this group are stored at the land_ice segment rate. (Type is String) dem_flag[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes long_name: DEM Source Flag (Type is String) units: 1 (Type is String) source: ATL03 (Type is String) valid_min: 0 (Type is Int8) valid_max: 4 (Type is Int8) contentType: referenceInformation (Type is String) description: Indicates source of the DEM height. Values: 0=None, 1=Arctic, 2=Global, 3=MSS, 4=Antarctic. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: none arctic global mss antarctic (Type is String) flag_values: 0, 1, 2, 3, 4 (Type is Int8) geoid_free2mean[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Geoid Free-to-Mean conversion (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: modelResult (Type is String) description: Additive value to convert geoid heights from the tide-free system to the mean-tide system. (Add to geoid to get the geoid heights in the mean-tide system.) (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) dem_h[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: DEM Height (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Height of the DEM, interpolated by cubic-spline interpolation in the DEM coordinate system to the PE location. (Best available DEM value in priority of Arctic/Antarctic/Global/MSS) (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) geoid_h[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Geoid Height (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Geoid height above WGS-84 reference ellipsoid (range -107 to 86m) in the tide-free system. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) geophysical(Type is Group) attributes description: The sun_and_clouds group contains parameters related to solar background and parameters indicative of the presence or absence of clouds. (Type is String) data_rate: Data within this group are stored at the land_ice_height segment rate. (Type is String) msw_flag[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: Multiple Scattering Warning Flag (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: -1 (Type is Int8) valid_max: 5 (Type is Int8) contentType: referenceInformation (Type is String) description: Multiple Scattering warning flag. The multiple scattering warning flag (ATL09 parameter msw_flag) has values from -1 to 5 where zero means no multiple scattering and 5 the greatest. If no layers were detected, then msw_flag = 0. If blowing snow is detected and its estimated optical depth is greater than or equal to 0.5, then msw_flag = 5. If the blowing snow optical depth is less than 0.5, then msw_flag = 4. If no blowing snow is detected but there are cloud or aerosol layers detected, the msw_flag assumes values of 1 to 3 based on the height of the bottom of the lowest layer: < 1 km, msw_flag = 3; 1-3 km, msw_flag = 2; > 3km, msw_flag = 1. A value of -1 indicates that the signal to noise of the data was too low to reliably ascertain the presence of cloud or blowing snow. We expect values of -1 to occur only during daylight. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: cannot_determine no_layers layer_gt_3km layer_between_1_and_3_km layer_lt_1km blow_snow_od_lt_0.5 blow_snow_od_gt_0.5 (Type is String) flag_values: -1, 0, 1, 2, 3, 4, 5 (Type is Int8) layer_flag[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes units: 1 (Type is String) source: ATL09 (Type is String) _FillValue: 127 (Type is Int8) long_name: Consolidated cloud flag (Type is String) valid_min: 0 (Type is Int8) valid_max: 1 (Type is Int8) contentType: referenceInformation (Type is String) description: This flag is a combination of multiple flags (cloud_flag_atm, cloud_flag_asr, and bsnow_con) and takes daytime/nighttime into consideration. A value of 1 means clouds or blowing snow are likely present. A value of 0 indicates the likely absence of clouds or blowing snow. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: likely_clear likely_cloudy (Type is String) flag_values: 0, 1 (Type is Int8) bsnow_conf[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: Blowing Snow confidence (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: referenceInformation (Type is String) description: Confidence flag for presence of blowing snow (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) bsnow_h[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Blowing Snow Layer Top Height (Type is String) units: meters (Type is String) source: ATL09 (Type is String) contentType: referenceInformation (Type is String) description: Blowing snow layer top height (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) tide_ocean[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Ocean Tide (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Ocean Tides including diurnal and semi-diurnal (harmonic analysis), and longer period tides (dynamic and self-consistent equilibrium). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) tide_earth[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Earth Tide (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Solid earth tides in the tide-free system. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) solar_azimuth[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: solar azimuth (Type is String) units: degrees_east (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: The direction, eastwards from north, of the sun vector as seen by an observer at the laser ground spot. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) r_eff[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Effective uncorrected reflectance (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Top-Level Fitting Routine (Type is String) contentType: referenceInformation (Type is String) description: Effective reflectance, uncorrected for atmospheric effects. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) dac[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Dynamic Atmosphere Correction (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) tide_load[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Load Tide (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Load Tide - Local displacement due to Ocean Loading (-6 to 0 cm). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) tide_earth_free2mean[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Earth Tide Free-to-Mean conversion (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Additive value to convert solid earth tide from the tide-free system to the mean tide system. (Add to tide_earth to get solid earth tides in the mean-tide system.) (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) bsnow_od[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Blowing snow OD (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) contentType: modelResult (Type is String) description: Optical thickness of blowing snow layer. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) tide_equilibrium[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Equilibrium Tide (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Long period equilibrium tide self-consistent with the ocean tide model (+-0.04m). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) cloud_flg_atm[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: Cloud Flag ATM (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 10 (Type is Int8) contentType: referenceInformation (Type is String) description: Number of layers found from the backscatter profile using the DDA layer finder. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) solar_elevation[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: solar elevation (Type is String) units: degrees (Type is String) source: ATL03 (Type is String) valid_min: -90. (Type is Float32) valid_max: 90. (Type is Float32) contentType: referenceInformation (Type is String) description: Solar Angle above or below the plane tangent to the ellipsoid surface at the laser spot. Positive values mean the sun is above the horizon, while negative values mean it is below the horizon. The effect of atmospheric refraction is not included. This is a low-precision value, with approximately TBD degree accuracy. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) tide_pole[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Solid Earth Pole Tide (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Solid Earth Pole Tide -Rotational deformation due to polar motion (-1.5 to 1.5 cm). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) e_bckgrd[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Expected background count rate (Type is String) units: hz (Type is String) source: ATL06 ATBD - Background PE Rate (Type is String) contentType: referenceInformation (Type is String) description: Expected background count rate based on sun angle, surface slope, for unit surface reflectance (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) cloud_flg_asr[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Int8) attributes _FillValue: 127 (Type is Int8) long_name: Cloud Flag ASR (Type is String) units: 1 (Type is String) source: ATL09 (Type is String) valid_min: 0 (Type is Int8) valid_max: 5 (Type is Int8) contentType: referenceInformation (Type is String) description: Cloud flag (probability) from apparent surface reflectance. 0=clear with high confidence; 1=clear with medium confidence; 2=clear with low confidence; 3=cloudy with low confidence; 4=cloudy with medium confidence; 5=cloudy with high confidence (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) flag_meanings: clear_with_high_confidence clear_with_medium_confidence clear_with_low_confidence cloudy_with_low_confidence cloudy_with_medium_confidence cloudy_with_high_confidence (Type is String) flag_values: 0, 1, 2, 3, 4, 5 (Type is Int8) bckgrd[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Background count rate (Type is String) units: hz (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Background count rate, derived from the ATL03 50-shot-average, interpolated to the segment center. (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) neutat_delay_total[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: Total Neutral Atmospheric Delay (Type is String) units: meters (Type is String) source: ATL03 (Type is String) contentType: referenceInformation (Type is String) description: Total neutral atmosphere delay correction (wet+dry). (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) bias_correction(Type is Group) attributes description: The bias_correction group contains information about the estimated first-photon bias, and the transmit-pulse-shape bias. (Type is String) data_rate: Data within this group are stored at the land_ice segment rate. (Type is String) fpb_mean_corr_sigma[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes units: meters (Type is String) _FillValue: 3.402823466e+38 (Type is Float32) long_name: fpb mean corr sigma (Type is String) source: ATL06 ATBD - First-Photon Bias Correction (Type is String) contentType: qualityInformation (Type is String) description: Estimated error in fpb_mean_corr (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) fpb_med_corr_sigma[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: fpb median corr sigma (Type is String) units: meters (Type is String) source: ATL06 ATBD - First-Photon Bias Correction (Type is String) contentType: qualityInformation (Type is String) description: Estimated error in fpb_med_corr (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) fpb_mean_corr[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: first photon bias mean correction (Type is String) units: meters (Type is String) source: ATL06 ATBD - First-Photon Bias Correction (Type is String) contentType: qualityInformation (Type is String) description: Estimated first-photon bias (fpb) correction to mean segment height (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) med_r_fit[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: mean median residual (Type is String) units: meters (Type is String) source: ATL06 ATBD - Top-Level Fitting Routine (Type is String) contentType: qualityInformation (Type is String) description: Difference between uncorrected mean and median of linear fit residuals (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) fpb_med_corr[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: fpb median corr (Type is String) units: meters (Type is String) source: ATL06 ATBD - First-Photon Bias Correction (Type is String) contentType: qualityInformation (Type is String) description: First-photon-bias correction giving the difference between the mean segment height and the corrected median height (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) tx_mean_corr[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: tx shape mean correction (Type is String) units: meters (Type is String) source: ATL06 ATBD - Transmit-pulse shape correction (Type is String) contentType: qualityInformation (Type is String) description: Estimate of the difference between the mean of the full-waveform transmit-pulse and the mean of a broadened, truncated waveform consistent with the received pulse (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) fpb_n_corr[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: fpb number photons corr (Type is String) units: counts (Type is String) source: ATL06 ATBD - First-Photon Bias Correction (Type is String) contentType: qualityInformation (Type is String) description: Estimated window photon count after first-photon-bias correction (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) tx_med_corr[ /gt3r/land_ice_segments/delta_time= 0..187] (Type is Float32) attributes _FillValue: 3.402823466e+38 (Type is Float32) long_name: tx shape median correction (Type is String) units: meters (Type is String) source: ATL06 ATBD - Transmit-pulse shape correction (Type is String) contentType: qualityInformation (Type is String) description: Estimate of the difference between the median of the full-waveform transmit-pulse mean and the median of a broadened, truncated waveform consistent with the received pulse (Type is String) coordinates: ../delta_time ../latitude ../longitude (Type is String) residual_histogram(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) data_rate: Data within this group are stored at the 200-meter along-track rate. (Type is String) description: This group contains histograms of the residuals between PE heights and the least-squares fit segment heights, at 200-meter along-track resolution. (Type is String) Dimensions: [ /gt3r/residual_histogram/delta_time = 0..21 ] [ /gt3r/residual_histogram/bin_top_h = 0..747 ] [ /gt3r/residual_histogram/ds_segment_id = 0..9 ] ds_segment_id[ /gt3r/residual_histogram/ds_segment_id= 0..9] (Type is Int8) attributes long_name: Segment ID Index (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) valid_min: 1 (Type is Int8) valid_max: 10 (Type is Int8) contentType: auxiliaryInformation (Type is String) description: Relative index of each segment_id used in the derivation of the histogram. (Type is String) lat_mean[ /gt3r/residual_histogram/delta_time= 0..21] (Type is Float64) attributes long_name: Latitude Mean (Type is String) standard_name: latitude (Type is String) units: degrees_north (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) valid_min: -90. (Type is Float64) valid_max: 90. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Mean latitude of the segments included in the histogram (Type is String) coordinates: delta_time lon_mean (Type is String) lon_mean[ /gt3r/residual_histogram/delta_time= 0..21] (Type is Float64) attributes long_name: Longitude Mean (Type is String) standard_name: longitude (Type is String) units: degrees_east (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) valid_min: -180. (Type is Float64) valid_max: 180. (Type is Float64) contentType: physicalMeasurement (Type is String) description: Mean longitude of the segments included in the histogram (Type is String) coordinates: delta_time lat_mean (Type is String) delta_time[ /gt3r/residual_histogram/delta_time= 0..21] (Type is Float64) attributes long_name: Elapsed GPS seconds (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) contentType: referenceInformation (Type is String) description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: lat_mean lon_mean (Type is String) bin_top_h[ /gt3r/residual_histogram/bin_top_h= 0..747] (Type is Float32) attributes long_name: Bin Top Height (Type is String) units: meters (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) contentType: physicalMeasurement (Type is String) description: Height of the top of each histogram bin, listed in increasing order. The bottom of each bin is equal to the top of the next- lowest bin. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) count[ /gt3r/residual_histogram/delta_time= 0..21] [ /gt3r/residual_histogram/bin_top_h= 0..747] (Type is Int32) attributes _FillValue: 2147483647 (Type is Int32) long_name: Bin Counts (Type is String) units: counts (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) contentType: physicalMeasurement (Type is String) description: Residual count falling with each histogram bin. The top height of each histogram bin may be found in the bin_top_h dataset. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) pulse_count[ /gt3r/residual_histogram/delta_time= 0..21] (Type is Float32) attributes long_name: Number of Histogram Segment Pulses (Type is String) units: counts (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) contentType: physicalMeasurement (Type is String) description: Number of pulses potentially included in the histogram (pulses are counted if they are in the central 20 m of each segment, even if no PE from the pulse are selected). (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) x_atc_mean[ /gt3r/residual_histogram/delta_time= 0..21] (Type is Float64) attributes long_name: Along Track Coordinate Mean (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) contentType: physicalMeasurement (Type is String) description: Mean along-track coordinate of the segments included in the histogram. (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) segment_id_list[ /gt3r/residual_histogram/delta_time= 0..21] [ /gt3r/residual_histogram/ds_segment_id= 0..9] (Type is Int32) attributes long_name: Segment ID List (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) contentType: referenceInformation (Type is String) description: Segments ids included in each column of the histogram (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) _FillValue: 2147483647 (Type is Int32) bckgrd_per_m[ /gt3r/residual_histogram/delta_time= 0..21] (Type is Float32) attributes long_name: Expected background PEs (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Residual_histogram calculation (Type is String) contentType: physicalMeasurement (Type is String) description: Number of background PE expected for each vertical meter of the histogram based on the observed background rate (bckgrd). (Type is String) coordinates: delta_time lat_mean lon_mean (Type is String) segment_quality(Type is Group) attributes DODS_EXTRA Unlimited_Dimension: delta_time (Type is String) data_rate: Data within this group are stored at the ICESat-2 20m segment rate. (Type is String) description: The segment_quality group contains a dense record (i.e. for every possible segment in the granule) of the success or failure of the surface-finding strategies, and gives the locations of the reference points on the RPTs. For segments with adequate data quality (i.e. with more than 10 PE) it also contains offsets into the data structures for the other groups that allow each segment to be efficiently located within the file. (Type is String) Dimensions: [ /gt3r/segment_quality/delta_time = 0..201 ] reference_pt_lat[ /gt3r/segment_quality/delta_time= 0..201] (Type is Float64) attributes long_name: Latitude (Type is String) units: degrees_north (Type is String) source: ATL06 ATBD - segment_quality group (Type is String) valid_min: -90. (Type is Float64) valid_max: 90. (Type is Float64) contentType: referenceInformation (Type is String) description: Latitude of the reference segment location on the RPT (Type is String) coordinates: delta_time reference_pt_lon (Type is String) standard_name: latitude (Type is String) reference_pt_lon[ /gt3r/segment_quality/delta_time= 0..201] (Type is Float64) attributes long_name: Longitude (Type is String) units: degrees_east (Type is String) source: ATL06 ATBD - segment_quality group (Type is String) valid_min: -180. (Type is Float64) valid_max: 180. (Type is Float64) contentType: referenceInformation (Type is String) description: Longitude of the reference segment location on the RPT (Type is String) coordinates: delta_time reference_pt_lat (Type is String) standard_name: longitude (Type is String) delta_time[ /gt3r/segment_quality/delta_time= 0..201] (Type is Float64) attributes long_name: Elapsed GPS seconds (Type is String) standard_name: time (Type is String) units: seconds since 2018-01-01 (Type is String) source: ATL06 ATBD - segment_quality group (Type is String) contentType: referenceInformation (Type is String) description: Number of GPS seconds since the ATLAS SDP epoch. The ATLAS Standard Data Products (SDP) epoch offset is defined within /ancillary_data/atlas_sdp_gps_epoch as the number of GPS seconds between the GPS epoch (1980-01-06T00:00:00.000000Z UTC) and the ATLAS SDP epoch. By adding the offset contained within atlas_sdp_gps_epoch to delta time parameters, the time in gps_seconds relative to the GPS epoch can be computed. (Type is String) coordinates: reference_pt_lat reference_pt_lon (Type is String) record_number[ /gt3r/segment_quality/delta_time= 0..201] (Type is Int32) attributes long_name: Land Ice Height Index (Type is String) units: 1 (Type is String) source: ATL06 ATBD - segment_quality group (Type is String) contentType: referenceInformation (Type is String) description: For those segments that have adequate signal strength, this parameter gives the record for the pair within the other groups in the granule. (Type is String) coordinates: delta_time reference_pt_lat reference_pt_lon (Type is String) signal_selection_source[ /gt3r/segment_quality/delta_time= 0..201] (Type is Int8) attributes long_name: Signal Selection Source (Type is String) units: 1 (Type is String) source: ATL06 ATBD - Signal selection base on ATL03 flags (Type is String) valid_min: 0 (Type is Int8) valid_max: 3 (Type is Int8) contentType: qualityInformation (Type is String) description: Indicates the last algorithm attempted to select the signal for ATL06 fitting. 0=Signal selection succeeded using ATL03 detected PE; 1=Signal selection failed using ATL03 detected PE but succeeded using all flagged ATL03 PE; 3=All signal-finding strategies failed. (Type is String) coordinates: delta_time reference_pt_lat reference_pt_lon (Type is String) flag_meanings: succeeded_using_pe succeeded_using_flagged_pe failed (Type is String) flag_values: 0, 1, 3 (Type is Int8) segment_id[ /gt3r/segment_quality/delta_time= 0..201] (Type is Int32) attributes long_name: Reference Point, m (Type is String) units: 1 (Type is String) source: ATL06 ATBD - segment_quality group (Type is String) contentType: referenceInformation (Type is String) description: Segment number corresponding to the second of two ATL03 segments in the ATL06 segment, counted from the RGT equator crossing (Type is String) coordinates: delta_time reference_pt_lat reference_pt_lon (Type is String) signal_selection_status(Type is Group) attributes description: The signal selection status subgroup contains the success or failure for each surface-finding strategies (Type is String) data_rate: Data within this group are stored at the ICESat-2 20m segment rate. (Type is String) signal_selection_status_all[ /gt3r/segment_quality/delta_time= 0..201] (Type is Int8) attributes units: 1 (Type is String) long_name: Signal Selection Status Flag (Type is String) source: ATL06 ATBD - Signal selection base on ATL03 flags (Type is String) valid_min: 0 (Type is Int8) valid_max: 3 (Type is Int8) contentType: qualityInformation (Type is String) description: Indicates confidence of the signal-selection algorithm using all ATL03-flagged PEs. 0=Signal selection succeeded using all ATL03-flagged PEs (or algorithm not attempted); 1=Signal selection using all ATL03-flagged PEs failed the 20-meter-spread test; 2=Signal selection using all ATL03-flagged PEs failed the 10-photon-count test; 3=Signal selection using all ATL03-flagged PEs failed both tests (Type is String) coordinates: ../delta_time ../reference_pt_lat ../reference_pt_lon (Type is String) flag_meanings: succeeded failed_20 failed_10 failed_both (Type is String) flag_values: 0, 1, 2, 3 (Type is Int8) signal_selection_status_confident[ /gt3r/segment_quality/delta_time= 0..201] (Type is Int8) attributes units: 1 (Type is String) long_name: Signal Selection Confident Flag (Type is String) source: ATL06 ATBD - Signal selection base on ATL03 flags (Type is String) valid_min: 0 (Type is Int8) valid_max: 3 (Type is Int8) contentType: qualityInformation (Type is String) description: Indicates confidence of the signal-selection algorithm using low or better PEs. 0=Signal selection succeeded using ATL03 low-or-better confidence PEs; 1=Signal selection using ATL03 low-or-better confidence PEs failed the 20-meter-spread test; 2=Signal selection using ATL03 low-or-better confidence PEs failed the 10-photon-count test; 3=Signal selection using ATL03 low-or-better confidence PEs failed both tests (Type is String) coordinates: ../delta_time ../reference_pt_lat ../reference_pt_lon (Type is String) flag_meanings: succeeded failed_20 failed_10 failed_both (Type is String) flag_values: 0, 1, 2, 3 (Type is Int8)

dataset: ATL06_20250913142324_13722807_007_01.h5
(dmr)

OPeNDAP Hyrax (1.17.1-997)
Documentation Questions? Contact Support

dataset: ATL06_20250913142324_13722807_007_01.h5 (dmr)

OPeNDAP Hyrax (1.17.1-997) Documentation Questions? Contact Support

dataset: ATL06_20250913142324_13722807_007_01.h5
(dmr)

OPeNDAP Hyrax (1.17.1-997)
Documentation Questions? Contact Support