This paper mainly deals with the problem of target localization with unknown wall parameters for through-the-wall radar imaging (TWRI) applications. A novel approach is presented to correct the shift in target position due to the ambiguities of the wall parameters. This approach is based on imaging by using at least two assumed wall relative permittivities. For each assumed relative permittivity, a sequence of target images are obtained using different assumed wall thicknesses, and a linear trajectory is formed via Radon transform. The intersection of these linear trajectories corresponding to different assumed relative permittivities is the estimated target position. Besides, the estimated wall parameters are acquired to form the high-quality image. Simulation and experiment results show that the estimated target positions with the proposed approach are well consistent with the true target locations, and the high-quality images are generated with the estimated wall parameters.
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