A DORT-Uniform Diffraction Tomography Algorithm for Through-the-Wall Imaging

Abstract

Strong reflections of the front wall in a through-the-wall imaging (TWI) system can challenge the detection of the scatterers behind the wall, and cause defocusing and displacement of the images. In this article, a generalized pencil-of-function (GPOF)-based wall mitigation approach is introduced and implemented along with a selective focusing algorithm for TWI. We develop and employ a wideband decomposition of the time-reversal operator (DORT) in conjunction with the uniform diffraction tomographic (UDT) imaging algorithm to image through a stratified medium. Selective focusing is achieved by tracking the singular value decomposition (SVD) of the time-reversal operator over the entire bandwidth of operation. The frequency independent phase of SVD is the main challenge in this process and has been solved by a new approach based on the decomposition formulation of UDT. The formulation of the proposed mitigation algorithm and DORT-UDT are presented along with simulated and measured results for validation. The efficacy of the method is demonstrated on a multistatic TWI system.