Non-Line-of-Sight ISAR Imaging Via Millimeter-Wave Automotive Radar

Non-line-of-sight (NLOS) imaging of moving targets is of tremendous interest in the fields of urban sensing and autonomous driving. In this paper, a novel NLOS inverse synthetic aperture radar (ISAR) imaging method is proposed for moving targets by automotive millimeter-wave (MMW). In this scheme, an imaging model of the moving target in urban scenes is developed and analyzed. A low-frequency filtering method is employed to remove stationary interfering signals, a typical threshold method is applied to extract the triple-reflected echo of a hidden moving target, and the range migration algorithm (RMA) is utilized to achieve envelope alignment. Then, the well-focused image of the moving target is achieved by the polar format algorithm (PFA) with Prominent Point Processing (PPP) autofocus algorithm. Finally, an outfield experimental system for the obscured moving targets is built by TI MMW sensors. The results demonstrate our method can provide a high-resolution image of the moving target.