ATLAS/ICESat-2 L2A Global Geolocated Photon Data, Version 6 USER GUIDE
This user guide describes NASA ATLAS/ICESat-2 L2A Global Geolocated Photon Data, Version 6, also identified as the ATL03 data product. It explains the data parameters, HDF5 file structure, data groups, ground-track and granule organization, and spatial and temporal coverage.
The guide also covers data acquisition and processing, including the signal-finding algorithm, geophysical corrections, height computation, photon event geolocation, range bias correction, surface masks, and geolocation segment rate parameters. It includes sections on quality, errors, and limitations, version history, and document information.
| Data Format | HDF5 formatted files |
|---|---|
| Parameters | Height above the ellipsoid, time, and geodetic latitude and longitude for individual photons |
| Reference Frame | Heights in ITRF2014; geographic coordinates referenced to WGS84 ellipsoid |
| Granule Span | About 1/14th of an orbit |
| Ground Track Width | Approximately 14 m wide |
| Spot Separation | Approximately 90 m across-track and 2.5 km along-track within each pair |
| Beam Energy Ratio | Approximately 1:4 between strong and weak beams |
| Reference Ground Tracks | 1,387 different RGTs |
| Repeat Cycle | Each RGT is targeted once every 91 days |
ATL03 data are provided as HDF5 formatted files.
The data provide height above the ellipsoid, time, and geodetic latitude and longitude for individual photons.
ATL03 data are segmented into granules that span about 1/14th of an orbit.
The beams within each pair have different transmit energies, with an energy ratio of approximately 1:4.