The influence of rain clutter on analysis of target polarization properties

As we all know, the polarimetric signature of a simple target can be obtained from its scattering matrix, which shows the complete information of target. When the electromagnetic wave travel through in rain medium, the propagation effect should not be ignored. The radar used can work on both circularly polarization and linear polarization mode. For the meteorological targets like rain medium, the reflection symmetry is considered here, basing on that, the analysis of propagation effect matrix at linear and orthogonal characteristic polarization can be easier than circular polarization, because it is the direct consequence of reflection symmetry. Firstly, this paper derives the polarization scattering matrix model of the target when the rain and snow cluster exitand furthermore, derives the scattering matrix inversion equations under two orthogonal vector basis, i.e., linear and orthogonal characteristic polarization. Then, a polarimetric calibration method by analyzing their corresponding polarization information is proposed. Finally, we show the extensive simulation results of sphere and Rayleigh scattering target. The results include the full-polarization scattering matrix inversed and the errors between the measured value and setting value in four polarimetric channels, which all demonstrate the validity of the method in this paper and achieve more accurate polarization characteristics of the target after getting rid of the impacts of rain and snow cluster.