Clutter Suppression and Moving Target Indication Using Deramp-STAP with Radon Transform for Multichannel HRWS SAR System

A bstract—Deramp space-time adaptive processing (Deramp-STAP) method can effectively reduce the number of channels used for azimuth ambiguity resolving in multichannel high-resolution and wide-swath (HRWS) SAR system. However, traditional Deramp-STAP needs to be conducted in all the ambiguity intervals of every frequency bin which results in a huge amount of calculation. In this paper, a novel Deramp-STAP method by using Radon Transform (RT) is proposed. Firstly, the STAP is operated in the zero Doppler ambiguity interval to suppress the clutter and extract the range information of the moving targets. After that, the equivalent relative speed of the moving target is estimated through RT, and then the frequency range of the moving target in azimuth Chirp Fourier Transform (CFT) frequency domain can be located. Also, the linear range migration (LRM) can be corrected due to the estimated equivalent relative speed. Then, the traditional Deramp-STAP is performed in the narrowed frequency region for every searching ambiguity number and the moving target can be indicated accurately. The effectiveness of the proposed method is validated by the simulation experiments.