Ground Moving Target Focusing and Motion Parameter Estimation Method via Modified Second-order Keystone Transform for Synthetic Aperture Radar

In this study, a ground moving target focusing and motion parameter estimation method based on modified second-order keystone transform (MSOKT) have been proposed for a synthetic aperture radar. Firstly, a cross-track velocity matching compensation function is derived to remove range walk migration and estimate the cross-track velocity of the moving target. Secondly, an MSOKT is proposed to remove the range curvature and Doppler frequency migration simultaneously. Lastly, a well-focused result of the moving target is obtained, and the motion parameters of the moving target are estimated. Compared with the traditional KT-based method, the proposed method works well in situations where Doppler centre blur and Doppler spectrum ambiguity are present. The computational complexity of the proposed method is considerably lower than that of the traditional optimum method, such as Radon-Lv's distribution. Simulation and real data processing results validate the effectiveness of the proposed method.