Non-Line-Of-Sight Target Imaging in Tomographic SAR by Multipath Signal Analysis

Non-line-of-sight (NLOS) target imaging is a challenging issue in Synthetic Aperture Radar (SAR), because obstacles may block the direct line of sight between the radar and the target. In SAR tomographic (TomoSAR)3D imaging, the wrong presence of NLOS points can impact the accuracy and interpretability of the results. This paper presents an approach that not only detects but also relocates NLOS targets to their actual positions. The method relies on multipath signal analysis within a geometric model. The simulation and experimental results on a drone-borne system with 4 channels demonstrate that the proposed approach can effectively image NLOS targets, and has the potential for practical applications.