A New wide-swath imaging and ground moving-target imaging scheme for MIMO-SAR based on azimuth phase coding*

In this study, a new wide-swath imaging and ground moving-target imaging (GMTIm) scheme was proposed based on azimuth phase coding (APC) for multiple-input multiple-output synthetic aperture radar (MIMO-SAR) systems. The new scheme transmitted multiple APC waveforms to different sub-regions of a scene for simultaneous imaging, converted range ambiguity into Doppler ambiguity, used azimuth digital beamforming (DBF) to suppress range ambiguity in static scenes, and employed elevation DBF to suppress range ambiguity of moving targets. Finally, imaging space time adaptive processing (ISTAP) was applied to each unambiguous sub-region to obtain imaging results for moving targets in wide swath. The main advantages of the proposed scheme include the suppression of range-ambiguous clutter and ambiguous moving targets via two-dimensional DBF, reduction of the influence of height fluctuations in the range direction on ambiguity suppression, and multiple range resolutions in different sub-regions. Furthermore, the feasibility of the proposed scheme was verified through theoretical analysis and simulations.