Jaming Chen (University of Bonn, Institute of Geodesy and Geoinformation, Germany ); Hakan Uyanik (University of Bonn, Institute of Geodesy and Geoinformation, Germany); Jürgen Kusche (University of Bonn, Institute of Geodesy and Geoinformation, Germany)

Advanced radar altimeter processing plays a key role in extracting water level variations in rivers, lakes and coastal zone. The Delay-Doppler processing, also called Un-Focused SAR (UFSAR), involves coherent summation of 64 pulses within a burst, resulting in an along-track resolution limited to 300 m. On the other hand, the Fully-Focused SAR processing (FFSAR) performs coherent summation of all pulses during the illumination time, enabling an along-track resolution approaching the theoretical limit of 0.5 m, allowing to observe smaller targets.

Here the FFSAR L1b processing chain uses the Omega-Kappa method. Impact of posting rate, zero-padding and Hamming window are investigated. As retracker the SAMOSA+ algorithm, known for its excellent performance in coastal and inland areas, is used. The FFSAR results are compared to the UFSAR of standard and in-house processing. This comparison provide an exhaustive evaluation of the similarities and differences between the results of processing applied to Sentinel-6. Finals differences to Sentinel-3 results are discussed.