| /gt1r/bckgrd_atlas/bckgrd_int_height: | Array of 32 bit Reals [delta_time = 0..89489] contentType: modelResult coordinates: delta_time description: The height of the altimetric range window. This is the height over which the 50-shot sum is generated. Parameter is ingested at 50-Hz, and values are repeated to form a 200-Hz array. long_name: Altimetric range window width source: ATL03 ATBD Section 7.3 units: meters |
| /gt1r/bckgrd_atlas/delta_time: | Array of 64 bit Reals [delta_time = 0..89489] description: Elapsed GPS Seconds from the ATLAS SDP GPS Epoch, referenced to the start of the 50-shot sum. This is based on every fiftieth laser fire time, which leads to a very close alignment with major frame boundaries (+/- 1 shot). 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. long_name: Time at the start of ATLAS 50-shot sum source: ATL02 standard_name: time units: seconds since 2018-01-01 |
| /gt1r/heights/lat_ph: | Array of 64 bit Reals [delta_time = 0..4102520] coordinates: delta_time lon_ph description: Latitude of each received photon. Computed from the ECF Cartesian coordinates of the bounce point. long_name: Latitude source: ATL03g ATBD, Section 3.4 standard_name: latitude units: degrees_north valid_max: 90. valid_min: -90. |
| /gt1r/heights/delta_time: | Array of 64 bit Reals [delta_time = 0..4102520] contentType: referenceInformation coordinates: lat_ph lon_ph description: The transmit time of a given photon, measured in seconds from the ATLAS Standard Data Product Epoch. Note that multiple received photons associated with a single transmit pulse will have the same delta_time. 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. long_name: Elapsed GPS seconds source: Operations standard_name: time units: seconds since 2018-01-01 |
| /gt1l/heights/dist_ph_along: | Array of 32 bit Reals [delta_time = 0..2923410] coordinates: delta_time lat_ph lon_ph description: Along-track distance in a segment projected to the ellipsoid of the received photon, based on the Along-Track Segment algorithm. Total along track distance can be found by adding this value to the sum of segment lengths measured from the start of the most recent reference groundtrack. long_name: Distance from equator crossing. source: ATL03 ATBD, Section 3.1 units: meters |
| /gt1l/heights/delta_time: | Array of 64 bit Reals [delta_time = 0..2923410] contentType: referenceInformation coordinates: lat_ph lon_ph description: The transmit time of a given photon, measured in seconds from the ATLAS Standard Data Product Epoch. Note that multiple received photons associated with a single transmit pulse will have the same delta_time. 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. long_name: Elapsed GPS seconds source: Operations standard_name: time units: seconds since 2018-01-01 |
| /gt3l/geolocation/segment_ph_cnt: | Array of 32 bit Integers [delta_time = 0..163492] _FillValue: 0 coordinates: delta_time reference_photon_lat reference_photon_lon description: Number of photons in a given along-track segment. In the case of no photons within the segment (segment_ph_cnt=0), most other parameters are filled with invalid or best-estimate values. Maintaining geolocation segments with no photons allows for the geolocation segment arrays to be directly aligned across the gtx groups. long_name: Number of photons source: Derived units: counts |
| /gt3l/geolocation/segment_length: | Array of 64 bit Reals [delta_time = 0..163492] coordinates: delta_time reference_photon_lat reference_photon_lon description: The along-track length of the along-track segment. Nominally these are 20m, but they vary from 19.8m to 20.2m. long_name: along-track segment length source: ATL03 ATBD, Section 3.1 units: meters |
| /gt3l/geolocation/delta_time: | Array of 64 bit Reals [delta_time = 0..163492] contentType: physicalMeasurement coordinates: reference_photon_lat, reference_photon_lon description: Transmit time of the reference photon, measured in seconds from the atlas_sdp_gps_epoch. If there is no reference photon, this time corresponds to the approximate mid-point time associated with the along-track geolocation segment edge. 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. long_name: Delta Time source: Derived standard_name: time units: seconds since 2018-01-01 |