Autofocusing imaging through the unknown building walls

A novel autofocusing real time TWI algorithm using SAR technique in the presence of wall ambiguities is proposed in this paper. A focusing time factor is introduced to obtain a dynamic image at different focusing time. The choice of the optimal image and the corresponding focusing time can be determined by a maximum entropy criterion. The spectrum Green´s function is employed to formulate through wall imaging algorithm, where the fast Fourier transform is used to achieve the image in a very short computation time. Simulation results show that the proposed algorithm can provide high quality focused image regardless of the estimated value of the wall parameters.