A Novel GEO-Airplane Arbitrary Squint Bistatic SAR Imaging Method Using Spectrum Compression and Alignment

Recently, GEO-Airplane Arbitrary Squint Bistatic SAR (GAS-BSAR) has become an attractive SAR imaging mode which could obtain Multi-Angle imformation from illuminated area. However, there is no excellent method to obtain high resolution SAR image from GAS-BSAR data. Fast Factorized BP (FFBP) is considered as an ideal methodology for configuration adaptability, but abundant interpolation operations extremely prolong FFBP imaging period. In this paper, a novel ground Cartesian back-projection (BP) algorithm is purposed for GAS-BSAR imaging. We decrease computation burden by subsitituding interpolation operations with Azimuth Zero-Padding Upsamping operations. Two-step spectrum conpression filters are designed to eliminate Azimuth spectrum aliasing before Azimuth upsamping. The purposed method named Bistatic Ground Cartesian BP (BGCBP) has been successfully applied to L-band GAS-BSAR simulation, where the efficiency improvement and imaging accuracy are demonstrated.