Velocity Estimation of Moving Targets Based on Least Square Fitting of High-resolution SAR Echo Sequences

Velocity estimation of moving targets is a key part of ground moving target imaging and positioning in airborne single-antenna high-resolution SAR system. In order to solute the defects of traditional algorithms, such as high computation brought by searching and interpolation and low reliability caused by range cell migration, a novel method based on least square fitting of echo sequence is proposed. Range changes between adjacent echo sequences are extracted using envelope correlation, and coefficients of range change equation are obtained by least square linear fitting, from which radial velocity and along-track velocity can be derived. Compared with the traditional algorithms, the new method has less computation and can work without RCMC. The mathematical model is presented and the principle of parameter selection is provided, and accuracy, computation and applicable conditions of the algorithm are analyzed. The effectiveness of the proposed algorithm is validated by simulation and real data.