Study on Polarimetric SAR Range Ambiguity Computation for Distributed Targets
Hong Wen①② Yang Shi-lin①②③ Li Yang①②③ Zhang Jing-jing①②③ Guo Sheng-long①②③
①(Science and Technology on Microwave Imaging Laboratory, Beijing 100190, China) ②(Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China) ③(University of Chinese Academy of Sciences, Beijing 100190, China)
A new approach is proposed to compute spaceborne SAR range ambiguity using covariance matrix. The causation of range ambiguity of spaceborne SAR and the ambiguous energy difference between like-polarized channel and cross-polarized channel are analyzed. In current study, it is common to use polarimetric scattering matrix to compute range ambiguity. Because of the speckle, the scattering matrix of a pixel can not describe the distributed targets precisely. Therefore, it is hard to decide the range ambiguity signal ratio of adjacent pixels. In this paper, the formulation of computing range ambiguity is derived for distributed targets first. Second, this new method is tested by using Radarsat-2 data. The results show that covariance matrix can effectively illustrate distributed targets. The results are smooth and confirmed. The new method is rational to compute range ambiguity of distributed targets.
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