Polarimetric SAR target detection based on polarization synthesis

This paper addresses the Polarimetric synthetic aperture radar (PolSAR) CFAR target detection utilizing the PolSAR synthesis technique. The optimal polarization ellipticity and orientation angles, which maximizes the ratio of the antenna receiver power between target and clutter (SCR), are searched in the co-polarized and cross-polarized channels, and the obtained antenna receiver power is named as the polarization synthesis enhancement (PSE) metric. Using the PSE metric, a data fitting based target detection scheme is presented. First, the Fisher distribution, which has extensive modeling capacity in a large set of clutters, is utilized to fit the distribution of PSE metric. Then, the corresponding “Second Kind Statistics” (SKS) parameter estimator is presented and the numerical solution of the detection threshold is also derived. Afterward, the CFAR detection is implemented. The experimental results demonstrate the enhancement results of PSE metric are almost comparable with that of the Polarimetric Matched Filter (PMF) detector. However, the computation load of PSE metric is generally less than that of the PMF. Moreover, the target detection results show the CFAR detector based on the Fisher distribution can realize the accurate target detection in homogenous and heterogeneous clutter areas.