Robust model for retrieval sea surface current from different RADARSAT-1 SAR mode data

Abstract

This paper presents the application of robust model to simulate sea surface current pattern. We have developed the horizontal surface velocity model which is estimated from the Doppler frequency theory to model out the sea surface current velocity. The robust model was applied to the RADARSAT-1 SAR satellite at three different modes (Wide-3, High extended-6 and Standard-2). The results of the study were validated using real time in situ current measurements that were acquired by AWAC equipment. It is found that the velocity and direction of the current changed through the period of the study according to the changing of Doppler frequency shift. Onshore sea surface current was modeled from Wide-3 mode varied between 0.22 to 0.25 m/s, while sea surface current velocities extracted from the Extended High-6 and Standard-2 modes were ranged between 0.16 to 0.53 m/s and 0.52 to 0.65 m/s, respectively. The RMS difference between the three RADARSAT-1 SAR images is 0.136, 0.364, and 0.485 in the Standard-2, Wide-3, and Extended High-6 mode, respectively. This shows that RADARSAT-1 Standard-2 mode is the best mode which can be used to simulate sea surface current patterns (velocity and direction).