A Frequency Domain Backprojection Algorithm Based on Local Cartesian Coordinate for Generally Bistatic SAR With Curve Track

Bistatic synthetic aperture radar (BiSAR) provides enhanced angle-of-view information compared to monostatic SAR, offering improved target detection capabilities. Nevertheless, the variance of the imaging geometric configuration will change the imaging parameters in the matched filter, causing image defocusing. To address this issue, we proposed a frequency domain back projection (FBP) imaging algorithm for generally BiSAR. First, a local cartesian coordinate is established to reduce the spatial variance of imaging parameters. Then, a discriminant criterion is introduced to classify subregions of the imaging region. Next, a novel FBP method is proposed to solve the spatial variance of the imaging parameters. Compared to other frequency domain algorithms, the FBP imaging algorithm can directly obtain ground image, which have same resolution as back projection algorithm. The results of simulated data and flight experiment demonstrate the effectiveness of the proposed FBP algorithm.