Efficient Correction Method for Polarimetric Distortion Error of Polarimetric Scatterometer

The full-polarization scatterometer is a new type of microwave scatterometer that can simultaneously measure the co-polarization and cross-polarization backscatter of the target. It can solve the wind direction ambiguity problem of the traditional scatterometer in the sea surface wind retrieval and improve the wind measurement accuracy. Moreover, the cross-polarization backscatter can effectively increase the sea surface wind speed measurement range and can be used for typhoon monitoring. High-precision sea surface wind retrieval using full-polarization scatterometer data first needs to correct the polarization distortion error of the full-polarization scatterometer system. To solve this problem, the polarimetric scattering coefficient model influenced by polarimetric distortion error is built based on the signal model of polarimetric scatterometer, and then the influence of polarimetric distortion error in quantitatively analyzed. Based on the polarimetric scattering coefficient model, some assumptions of ocean scattering characteristic and polarimetric calibration are introduced to establish the correction model of polarimetric scattering coefficients. Simulation data based on RADARSAT-2 polarimetric scattering coefficients of different sea region is corrected and results show that the proposed method can effectively correct of polarimetric distortion error and greatly improve the measurement accuracy of polarimetric scattering coefficients.