A Novel Motion Compensating Method for MIMO-SAR Imaging Based on Compressed Sensing

Multiple-input multiple-output-synthetic aperture radar (MIMO-SAR) can realize high-resolution imaging by its predominance of parallel sampling. However, the motion compensation and large data amount are the inevitable problems to be solved. In this paper, a novel motion compensating method for MIMO-SAR imaging with the under-sampled echo signal is put forward. First, the echo signal model of MIMO-SAR system with motion error is analyzed and a compensating method with the Nyquist-sampled echo data is proposed. Using the technique of two-step compensation, the motion error is compensated and the imaging result is obtained. Second, to compensate the motion error with the under-sampled echo signal, based on the above compensating method, the transform operator and the CS-based imaging scheme are constructed, which could implement the first-step compensation, range compression, and range cell migration correction simultaneously. At last, the imaging result is obtained by the second-step compensation and azimuth compression. Using the proposed method, just a small amount of imaging data is required for MIMO-SAR imaging. Finally, the effectiveness of the proposed method is proved by the imaging simulations.