Multifrequency Fusion Imaging Algorithm for Nonuniform Wall Scenarios

Through-the-wall radar (TWR) leverages the excellent penetration capabilities of low-frequency electromagnetic waves to achieve noninvasive and nondestructive detection of targets hidden behind the wall. However, the refraction and attenuation phenomena of complex walls have significantly affected the detection performance and imaging quality. Most of the traditional studies have made compensation based on ideal uniform wall structures. They only consider a single medium or a single thickness, which will lead to huge errors for actual nonuniform wall structures. To address the challenges, a multifrequency fusion imaging algorithm that can handle urban nonuniform walls is proposed in this article. First, a segmented wall compensation algorithm is proposed for nonuniform wall scenarios to address poor focusing effects. Second, this article proposes a multifrequency fusion algorithm that integrates high-frequency data with low-frequency data to improve resolution in nonuniform wall environments. Finally, simulation and experimental results demonstrate the superiority of the proposed algorithm under nonuniform wall scenarios.