Cylindrical MIMO-SAR Imaging and Associated 3-D Fourier Processing

In this paper, we propose a new three dimensional cylindrical imaging system based on the combination of a multiple-input multiple-output arc array in azimuth and a synthetic aperture radar on the vertical dimension for applications focused on buried threat detection. Imaging algorithms are adapted to these specific transceiver distributions in order to accelerate reconstructions in the Fourier domain. Following theoretical developments, an experimental proof of concept is proposed at 6 GHz using a circular dual positioning system specifically designed for these new studies. The validity of the proposed techniques is extended to larger cylindrical arrays using numerical simulations of complex volumetric scenes in the 5-12 GHz band. This work allows for significant gains in computation time for these specific imaging systems, which are more than three orders of magnitude shorter than those of conventional backpropagation techniques in the studied cases composed of more than 250,000 voxels.