An Accelerated Back Projection Algorithm via Recursive Spectrum Fusion for High-Speed High-Squint SAR Imaging with Curved Trajectory

For high-speed-high-squint synthetic aperture radar (HSHS-SAR) with curved trajectory, the ineffectively aligned spectrum is inevitably involved in state-of-the-art fast back projection algorithms (FBPAs), which degrades their imaging performance both in efficiency and accuracy. In this paper, the polar coordinates (PC) based-FBPA is proposed for HSHS-SAR with curved trajectory, which is referred to as PC-FBPA. In the designed PC, the spectra of different scatterers exhibit consistent support regions, which significantly facilitates the spectrum alignment for the non-interpolated sub-image merging process. This approach achieves high performance both in efficiency and accuracy for HSHS-SAR with curved trajectory. Simulation and raw data experiments are provided and analyzed to validate the performance superiority of the proposed algorithm.