Three-Dimensional Down-View Imaging Based on MIMO Through-Wall-Radar

MIMO through-wall-radar is traditionally utilized to perform forward-view imaging (FVI) for the hidden targets behind the wall. Due to the limited view angle and target occlusion, FVI usually suffers from the problem of target missing in the case of multiple targets. In this paper, a novel down-view imaging (DVI) mode is presented to obtain robust three-dimensional (3D) multiple target images without target missing. Specifically, the propagation characteristic is analyzed for the 3D DVI in an enclosed building space. Then the DVI algorithm is introduced. Specifically, the back-projection algorithm is applied to form a 3D image and the exponential phase coherence factor (EPCF) weighting is adopted to suppress the multi-path ghosts. Based on the gprMax simulation results, in the presence of target occlusion, it is demonstrated that the presented DVI method has the ability to implement robust imaging for multiple targets, while the FVI misses the obscured target.