CoAuthors

Luciana Fenoglio-Marc (Univeristy of Bonn, Germany); Salvatore Dinardo (HeSpace/EUMETSAT, Germany); Remko Scharroo (EUMETSAT, Germany); Jerome Benveniste (ESA/ESRIN, Italy); Matthias Becker (TU Darmstadt, Germany)

For Jason-CS, which is going to be launched 2020, a new mode designated to the open ocean called Low Resolution Mode Range Migration Corrected (LRMC) is planned to reduce the data volume. This new processing method is similar to SAR mode but without performing a beam steering to selected surface samples. This leads to a Low Resolution Mode (LRM) kind of footprint which however has a beam forming and range migration correction (RMC) step applied. The resolution is as LRM, the precision is similar to SAR.

This study focuses on the effect of geoid curvature and slope in the generation of the waveforms using RDSAR, LRMC and SAR mode processing and in their successive processing to estimate the Level 2 products. The three usual parameters sea surface height, significant wave height and wind speed are investigated.

This is going to be performed by approximating the local surface around the nadir of the center of four bursts by a torus using methods of elementary differential geometry. This more general surface representation is used to update the range migration correction (RMC) formula and the SINC waveform model for conventional and SAR altimetry.

The area of interest in this study is the CryoSat-2 SAR box including a part of the Mariana Trench extending from 0° N to 17° N and 137° E to 150° E as in this area a high impact of geoid curvatures and slopes is expected. Level 2 parameters are computed for two different surface approximations which are the ellipsoid and the geoid. Results are compared to identify any effect of curvature and slope on the LRMC and SAR mode processing.