ATI and GMTI Performance Analysis of Post-Sentinel-1 SAR Systems based on Simulations using OASIS

With the Sentinel-1 expected to be launched at the end of 2013, ESA is already funding activities to study the next generation of C-band SAR instruments. One of the drivers for these developments is the strong user re-quirement for high resolution and wide swath (HRWS) operations, which can be realized by using Multiple Azi-muth Phase centers (MAPS). The current reference system for a post-Sentinel-1 instrument features a 12.8 m long antenna divided along-track in 8 panels which, on receive, are sampled independently. To investigate the final performance in terms of surface current velocity estimation errors, a full multi-channel SAR simulator for open-oceans (OASIS: Ocean ATI-SAR SImulator) has been implemented. This simulator generates multi-channel raw data corresponding to a time-varying simulated ocean surface that includes all main environmental effects, and uses prototypes of the proposed processing algorithms. A detailed performance analysis in terms of final ATI performance is presented in this paper.