2-D Spatial Variation Bistatic Forward-Looking SAR Imagery

Under the special geometric model of bistatic forward-looking synthetic aperture radar (SAR), the 2-D spatial variation problem makes it difficult for traditional algorithms to achieve well-focused imaging, which limits the imaging area. In this letter, from the perspective of range-azimuth decoupling of signal, dechirping processing and keystone transform are used to realize range-variant phase compensation and range cell migrations (RCMs) correction. Based on the range-azimuth decoupled signal, the overlapped subaperture processing can eliminate the azimuth-variant quadratic chirp rate phase in each range cell. Experimental results demonstrate that the proposed method is suitable for the bistatic forward-looking SAR (BFSAR) system to solve the 2-D spatial variation problem and achieve well-focused imaging.