A New Polarimetric Calibration Method for C-band Spaceborne SAR Based on Scattering Model of Amazon Rainforest

In this paper we propose a new polarimetric calibration method for C-band spaceborne SAR based on scattering model of amazon rainforest. The well-known Freeman-Durden model is used to express the polarimetric scattering mechanisms of amazon rainforest for C-band spaceborne SAR, and then nonlinear equations with polarimetric distortion parameters are built by use of covariance matrix and solved iteratively to get the polarinetric distortion matrix (PDM). In comparison with the Quegan method, no approximation is used in our method and therefore we can solve all the polarimetric distortion parameters more accurately, even if the crosstalk is high. Moreover, both channel imbalances and crosstalks can be directly estimated by our method, which is more practical as no artificial reflectors are needed to determine the channel imbalances. Simulations based on the RADARSAT-2 data confirm the validity and feasibility of the proposed method.