Autofocusing imaging through the unknown building wall with EM inverse scattering algorithm

The through‐wall imaging (TWI) problem is studied within the context of EM inverse scattering in this article.A novel real time TWI algorithm is proposed by employing the spectrum Green's function and exploding source model under Born approximation. The complex scattering process because of the presence of the wall is well modeled in the imaging formulation through the layered medium Green's function. Inspired by the concept of time reversal imaging, a novel autofocusing strategy is incorporated in the proposed algorithm. The autofocusing is achieved by introducing a time factor in the TWI formulation to get a dynamic image at different focusing time. The image at the time instant, when the defined entropy is minimized, is stored as the output of the imaging result. Numerical and experimental results are presented to show that the proposed method can provide high quality focused image in a short computation time regardless of the estimated value of the wall parameters.