A Radial Velocity Estimation Method of Moving Target for Azimuth Multichannel Hrws Sar

In the azimuth multichannel (AMC) synthetic aperture radar (SAR) system, the large receiver is divided into several small receivers with uniform distribution, and high-resolution wide-swath (HRWS) imaging is achieved by using a low pulse repetition frequency (PRF). However, a low PRF will result in Doppler ambiguity for each channel and ambiguous radial velocity estimation. In this paper, an effective unambiguous radial velocity estimation method for a ground moving target is proposed. First, the baseband radial velocity is estimated quickly by calculating the energy ratio of the reconstructed Doppler spectrum. Then, the Doppler ambiguity number is estimated by using the Radon transform (RT). Finally, unambiguous radial velocity estimation can be achieved, and the proposed method has lower time complexity than the method based on traversal search. Numerical simulation results prove the effectiveness and accuracy of the proposed method.