Optimum polarimetric analysis of backscattering from rough sea surface

Using SIR-C/X-SAR that provided simultaneously images of Southern-China Sea at three microwave wavelengths, L-band quad-polarization, C-band quad-polarization and X-band with VV polarization, the present paper calculate and analyze the optimum polarization of the backscattering from the rough sea surface. The utmost applications of radar remote sensing of ocean come down to quantitative derivation of some oceanographic parameters instead of simple interpretation of patterns on the SAR image itself of ocean surface. Accordingly, we concern mainly the polarimetric parameters of return signals from sea surfaces relate some physical oceanographic variables. Since the backscattering matrix contains the backscattering information of moving sea surface, concentration should be on understanding the properties of this matrix alone. Meanwhile, polarization is a key to aim this goal. A physical approach is to study polarization optimization. The optimization result shows that an optimum polarization changes with position of sea surface. And as a heuristic derivation, we prove that there exist optimum polarimetric responses with orientations at all sea-wind conditions.