A Two-Stage Wall Parameter Estimation Algorithm for UWB Through-the-wall Radar

The knowledge of wall parameters in through-the-wall radar imaging is important since it is the guarantee of high precision target localization. Hence, this paper presents a two-stage wall parameter estimation algorithm to retrieve the unknown distance, thickness, and relative permittivity. In this approach, the time delays of the front and rear surfaces of a wall with respect to all potential wall parameters are calculated by specular reflection and refraction point approximation. Since the echoes of all antennas will constructively accumulate only when the time delays are equal to the true value, the image intensity generated by the back-projection algorithm can be used to discriminate the parameters. Finally, electromagnetic simulations demonstrate that the proposed algorithm can precisely estimate the walls parameter and is flexible for different array structure.