Moving Target Localization in Building Shadow Areas

‍ ‍Urban environments are typically comprised of a variety of buildings， which obstruct each other and produce multiple building shadow areas. Detecting targets within these shadow areas is very challenging for radar systems because of the lack of line-of-sight signals owing to blockage by buildings. To address this issue， this study proposes a novel method to locate moving targets within building shadow regions based on multipath reflection signals. First， fast Fourier transform （FFT） and spectral analysis are jointly used to estimate the relative distance and velocity of the targets based on the high-resolution abilities of linear frequency modulated continuous wave （LFMCW） signals in terms of distance and velocity. Second， by exploring the relationship between the multipath signal propagation law and building layout， the absolute distance and velocity of the moving targets are further estimated by leveraging a distributed radar architecture. Finally， utilizing the geometric relationship between the radar system and building layout， the absolute position and velocity of the targets within the shadow regions are estimated， enabling the localization of moving targets. To validate the performance of the proposed approach， extensive simulation experiments were conducted for targets with different moving speeds and directions. The simulation results demonstrate that the proposed method can achieve high accuracy in localization of moving targets in building shadow regions， regardless of the moving speeds and directions. This significantly increases the detection coverage area and demonstrates potential for improving the detection effectiveness-cost ratio of radar systems by utilizing multipath signals.