Time-Reversal Through-Wall Microwave Imaging in Rich Scattering Environment Based on Target Initial Reflection Method

摘要

In recent years, time reversal (TR) methods have been widely employed in microwave imaging (MI) applications due to their efficient functionality in heterogeneous media. One of the applications turning into a great interest is through-wall microwave imaging (TWMI). In this paper, classic TR method is applied to detect and localize a target obscured by a brick wall inside a rich scattering environment using numerically generated data. Regarding this, it is shown when the signals acquired by a set of receivers are time reversed and backpropagated to the background media, finding an optimum time frame which the constituted image represents a true location of the target becomes infeasible. Indeed, based on target distance and increasing multiple scattering in the media the previously-used maximum E-field method and entropy-based methods fail to select the optimum time frame. As a result, an improved procedure named target initial reflection method (TIRM) is proposed. Even in the case of rich scattering environment, the results show this method prevails over the incapabilities of the former methods.