Fourier-based radar processing for multistatic millimetre-wave imaging with sparse apertures

Fourier-based radar processing algorithms have attracted a lot of interest among imaging techniques mostly because they are extremely fast. Moreover, such techniques can be integrated with a Multiple-Input Multiple-Output (MIMO) effective aperture to form a cost-effective imaging system that can retrieve an estimation of the scene in real-time. The proposed technique leverages the phase center approximation and a multistatic-to-monostatic data conversion to render the back-scattered measurements compatible with fast Fourier processing. Whereas the phase center approximation is applicable for imaging in the far-field of the synthesized aperture, in the near-field, a more sophisticated aperture design should be considered to reduce the distortion in the reconstructed images. This paper presents a theoretical study for a sparse aperture design and the optimization of the aperture layout for near-field imaging. Furthermore, it proposes a GPU accelerated reconstruction algorithm able to form 3D images in a few milliseconds with low-cost hardware.