Jason-CS Interleaved Mode Data Simulations, Echo Model Generation and Performances Assessment
Boy, Francois; Picot, Nicolas; Desjonqueres, Jean-Damien

In the frame of the Sentinel3 project, CNES has developped an instrument simulator called the SAR Altimeter Simulator (SAS) able to generate Doppler echoes for different flight and instrument configuration and sea state. Today, this simulator is the core system of the SAR/Doppler numerical model and retracking algorithm used to process CRYOSAT-2 SAR data on CNES side. Results of CRYOSAT-2 SAR data processed using this simulator have been largely presented at OSTST, 2012 and AGU, 2012 and its efficiency has been demonstrated. On another hand, Jason-CS will embark an interleaved mode which will provide simultaneously LRM and SAR measurements. While the LRM echoes can be processed using a classical Brown model, the SAR echoes from the interleaved mode will exhibit a very new shape that can not be retracked with current SAR/Doppler models developped for CRYOSAT-2 and Sentinel-3. A dedicated SAR model must be developped for the Jason-CS interleaved mode. In preparation, CNES has upgraded the SAS to include this new technique. In the frame of the ESA living planet symposium, using the SAS simulator, we propose first to show Jason-CS echoes simulations for different sea states. Then we will present how did we build a SAR doppler model for the interleaved mode. To finish we will assess the performances of this new mode on simulated data.