Oceanographic Applications of Spaceborne Bistatic SAR

This work presents an analysis of the attainable performance of a bistatic SAR for oceanographic applications, such as the determination of sea state parameters and the reconstruction of the sea wave spectrum. The analysis has been developed with regard to the spaceborne bistatic SAR of the BISSAT mission. It is based on a receiving-only antenna, flying on board a small satellite, that gathers echoes from the area illuminated by an active SAR operating on an independent large platform. It is shown that in the case of bistatic acquisitions the region of the sea wave spectrum that can be retrieved through linear inversion is wider than the one relevant to a monostatic survey. Specifically, the improvement consists of higher sea states (up to 15-20%) and a wider range of azimuth angles of propagation of the sea waves, increasing for larger antenna baselines. Also, the image degradation due to acceleration smearing is reduced. Improvements can achieve 20% for larger azimuth angles of propagation and baselines.