An Extended Time Scaling Algorithm based on the Spatial Inverse Mapping for Bistatic SAR Imaging with Complex Trajectory

Bistatic synthetic aperture radar (BiSAR) can perform remote imaging at any position, thus playing a crucial role in remote sensing applications. In BiSAR imaging with complex trajectory (CT-BiSAR), an inevitable issue is the complicated correspondence between the geometry space and signal space, which will cause Doppler parameters mismatch and affect the imaging performance. To address this problem, the spatial inverse mapping relationship is skillfully constructed through the method of series reverse (MSR), which accurately describes the specific correspondence between the geometry space and signal space. On this basis, an extended time scaling (ETS) algorithm is proposed. Its innovation is compensating for spatially variant Doppler phase that causes image distortion and defocusing by introducing the preprocessing and scaling functions in the time and frequency domains, respectively. Simulation experiments validate the effectiveness of the proposed method.