Through Wall Imaging Based on the Space-Frequency Time Reversal

Two approaches for through wall imaging are proposed based on the space-frequency time reversal (SF-TR). Through the space-frequency measurement by the antenna array, the electromagnetic returns are recorded and used to form the space-frequency multistatic data matrix (SF-MDM). Applying the singular value decomposition (SVD) to the SF-MDM generates the left singular vectors that can be used to construct the imaging pseudo-spectrum for the target. Instead of the traditional SF-MDM, two new SF-MDMs are employed for wall clutters mitigation. As for the stationary target detecting, the total SF-MDM is used to enhance the target response and mitigate the wall clutters. As for the moving target tracking, the differential SF-MDM is used to suppress the wall clutters by exploiting the target movement which achieves high efficiency. To evaluate the performance of the proposed methods, numerical simulations are carried out and it is demonstrated that the proposed methods are effective in detecting target obstructed by the wall and tracking target moving behind the wall in real time.