MC-RMA: Multi-Coset Range Migration Algorithm for Near-Field MIMO-SAR Imaging

This paper addresses the important problem of near field MIMO-SAR imaging with non-uniform MIMO radar. We propose a new approach referred as Multi-Coset Range Migration Algorithm (MC-RMA), which leverages the well known periodic block scanning of MIMO radars in RMA to create uniformly spaced multiple sub-arrays. These sub-arrays are formed by combining corresponding elements across this periodic block scan, and the elements in these sub-arrays are uniformly spaced despite the non-uniformity of the MIMO radar. By visualizing them as decimated and translated versions of a larger array, a closed-form expression connecting their Fourier transforms (FT) and the FT of the larger non-uniform array is derived. Unlike existing methods, MC-RMA requires computation of smaller dimensional FFTs making it more deployment friendly. Further, experimental results are presented which demonstrate a significant improvement in image reconstruction with reduced computation compared to state-of-the-art methods.