Sequential Frequency-Domain Imaging Algorithm for Near-Field MIMO-SAR With Arbitrary Scanning Paths

This paper presents a sequential algorithm for near-field multiple-input multiple-output synthetic aperture radar (MIMO-SAR) imaging. This method can be decomposed into a reconstruction for MIMO array with the range migration technology and a reconstruction for synthesis aperture with the backprojection technology. Different to the range migration algorithm (RMA), the method does not adopt the Fourier transform along the scanning direction; therefore, it can be used for MIMO-SAR systems with arbitrary scanning paths and can perform imaging during the array scanning. In addition, due to its sequential imaging scheme, the proposed method is conducive to parallel processing and reduces the computational memory consumption. Both theoretical analysis and experimental results show that, compared with the RMA and the backprojection algorithm, the proposed method can achieve the same imaging results but with the lowest computational load.