Target-to-Target Interaction in Through-the-Wall Radars under Path Loss Compensated Multipath Exploitation-Based Signal Model for Sparse Image Reconstruction

Abstract

Multipath caused by reflections from interior walls of buildings has been a long-standing challenge that affects through-the-wall radar imaging. Multipath creates ghost images that introduce confusion when detecting desired targets. Traditionally, multipath exploitation techniques under the compressive sensing framework have widely been applied to address the challenge. However, the multipath component emanating from target-to-target interactions has not been considered–a consequence that may, under multiple target scenarios, lead to incorrect image interpretation. Besides, far targets experience more attenuation due to free space path loss, hence resulting into target undetectability. This study proposes a signal model, based on multipath exploitation techniques, by designing a sensing matrix that incorporates multipath returns due to target-to-target interaction and path loss compensation. The study, in addition, proposes the path loss compensator that, if integrated into the proposed signal model, reduces path loss effects. Simulation results show that the Signal to Clutter Ratio and the Relative Clutter Peak improved by 4.9 dB and 1.9 dB, respectively, compared with the existing model.