Time-Frequency Domain Hybrid Algorithm for Near-Field MIMO-SAR Imaging

A time-frequency hybrid algorithm for three dimensional near field sparse multi-input multi-output (MIMO) synthetic aperture imaging is proposed in this paper. The algorithm transforms the data of synthetic aperture dimension in wavenumber domain by fast Fourier transform, and compensates the spares MIMO modulated phases using two dimensional back-projection in each wavenumber slices. Then three dimensional image is reconstructed by inverse fast Fourier transform. Compared to direct back-projection algorithm, the proposed algorithm reduces calculation expenses significantly while providing a fairly precise focusing ability.