220 GHz Sparse Imaging with Multi-static Aperiodic Array

Abstract

This paper proposes a simple design method for a multi-static aperiodic array to achieve 220 GHz sparse imaging, and a corresponding image reconstruction algorithm based on Fast Fourier Transform (FFT) and sparse data recovery. The proposed aperiodic sparse array originates from the linear sparse periodic array (SPA), it can further save the number of sampling data, transceivers and system cost compared to SPA imaging system. Low rank matrix recovery technique with principal component pursuit by alternating directions method (PCPADM) is used to recover the missing data caused by the sparse sampling. In order to achieve fast image reconstruction, FFT-based matched filtering method is used in which multistatic-to-monostatic conversion and interpolation are applied for data pre-processing. The proposed imaging scheme has been verified in experiments. An imaging resolution of 6 mm resolution is achieved at 1.4 m with 192 mm × 300 mm field of view, with a significantly reduced reconstruction time in comparison to the generalized synthetic aperture focusing technique (GSAFT).