Study on transmitting mode and imaging algorithm of MIMO-SAR

High resolution and wide-swath image can be obtained by Multiple-Input Multiple-Output (MIMO) SAR at the state-of-the-art level. In this paper the technique of MIMO-SAR imaging based on frequency domain bandwidth synthesis is researched. Firstly we use Orthogonal Frequency Division Linear Frequency Modulation (OFD-LFM) waveform as the transmitting signal of MIMO-SAR, and design the system's transmitting mode primarily. Then for the restraints brought by wide bandwidth and wide swath to the imaging algorithm, we choose the high precise Range Migration Algorithm (RMA) to deal with the echo data. Finally an imaging flow using RMA combined with sub-band synthesis in frequency domain is proposed. Compared with the time domain sub-band combination method, the proposed imaging flow not only insures the image precision but also has fewer operating steps and lower computational load, which greatly improves the computing efficiency.