FOCUSING TRANSLATIONAL VARIANT BISTATIC FORWARD-LOOKING SAR DATA BASED ON TWO-DIMENSIONAL NON-UNIFORM FFT

Forward-looking imaging has extensive potential applications, such as self-navigation and self-landing. By choosing proper geometry, bistatic synthetic aperture radar (BiSAR) can break through the limitations of monostatic SAR on forward-looking imaging and provide possibility of the forward- looking imaging. In this special bistatic conflguration, two problems involving large range cell migration (RCM) and large range-azimuth coupling are introduced by the forward-looking beam, which make it di-cult to use traditional data focusing algorithms. To address these problems, a novel Omega-K algorithm based on two-dimensional non-uniform FFT (2-D NUFFT) for translational variant (TV) bistatic forward-looking SAR (BFSAR) imaging is proposed in this paper. In this study, we derive an accurate spectrum expression based on two-dimensional principle of stationary phase (2-D POSP). 2-D NUFFT is utilized to eliminate the range-variant term, which can make full use of the data and improve the computational e-ciency as well. The experimental results, presented herein, demonstrate the efiectiveness and advantages of the proposed algorithm.