A Fast Algorithm for SAR Imaging of Ground Moving Target Based on TRP-DPT and NUFFT

Unknown relative motion between moving target and radar platform causes defocus of synthetic aperture radar (SAR) image. Doppler ambiguity will occur when the target moves at a high speed due to the system pulse repetition frequency (PRF) limitation. Considering the complex motion in the presence of acceleration makes it difficult to refocus the moving target. This paper proposes a fast algorithm for SAR imaging of ground moving target based on time-reversal process (TRP), discrete polynomial phase transform (DPT) and non-uniform Fourier transform (NUFFT), which can simultaneously estimate the target’s unambiguous cross-track velocity and higher-order motion parameters. This algorithm does not require parameter search and its computational complexity is low. Simulation and radar real data experimental results show that the algorithm has a well-focused effect on high-speed moving targets.