A Novel Approach for Ground Moving Targets SAR Imaging Based on Second Order Keystone Transform

In ground moving target imaging, migration through range cells (MTRC) would cause worse imaging result than that in static target imaging. For the large range curvature cannot be effectively resolved by usual keystone algorithms, a novel approach aiming at solving this phenomenon is proposed in this paper. It uses second order keystone transform to correct the range curvature in the data after range compression. Then, the matched filter can be constructed with estimated Doppler center frequency and Doppler rate. Therefore, the moving targets can be indicated in focused SAR image. Simultaneously, the estimated Doppler parameters can be used to calculate the instantaneous motion parameters. Finally, simulation imaging result of point targets shows the effectiveness of the proposed approach.