National Aeronautics and Space Administration

Goddard Space Flight Center

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Data Products

Data Products

Level 1 Waveform Data Records

Orbital format waveform data records at the full data rate which contain the time, location altimeter return waveform, and retracking parameters.

Level 2 Ice Data Records

Orbital format ice data records at the full data rate which contain the time, precise location, altimeter height measurement, corrected precise surface elevation, atmospheric corrections, tidal values, retracking corrections, and AGC. This data is updated on-line as more precise orbits, corrections, and tide values become available.

Level 3 Geo-referenced Database

Contain surface height measurements derived from altimetry data, ordered by geographic areas or "bins". Each data record contains the geodetic position, revolution number, surface elevation relative to a reference ellipsoid, and slope correction.

Level 4 Elevation Grids

Gridded elevations are calculated from the data by a weighted fitting of a bi-quadratic function (bi-linear where data distribution is poor) on a polar stereographic projection with a nominal spacing of 5 km (ERS-1) 10 km (GEOSAT) and 20 km (Seasat).

Crossover Data

Gives interpolated elevations for different tracks at the same location including the corrections also interpolated to the crossover location.