Polarization calibration technique of fully polarimetric radar

Disturbed by the non-ideal factor, the polarimetric measuring radar can not get the correct polarization scattering matrix(PSM) of the target directly, so high-accuracy polarimetric calibration is the foundation of acquiring and using polarimetric information. This paper begins with the principle of polarimetric calibration, and then builts the error model of PSM measurement, analyzes the impact of error factors on the PSM measurement results, introduces the main passive and active polarimetric calibration methods and compared the property and applied situation of them, and finally, analyzes the influence of calibration object parameters on the calibration precision, all of which lays a foundation for the using of polarimetric information. The analytical results show that the measuring value of the target cross-polarization is different from its true value apparently when the target cross-polarization approximately equals the polarimetric isolation of the system. The measuring deviation caused by the system polarimetric isolation can be reduced by passive or active polarimetric calibration object whose polarimetric isolation is better than that of the radar system. All these works will lay foundations for the design and preparation of the polarimetric calibration object, and also the calibration of the fully polarimetric radar.