A novel technique to overcome wall ambiguities in through-the-wall radar imaging applications

In the through-the-wall radar imaging applications, errors in wall parameters cause targets to be imaged away from their true positions. The shifts of target locations depend on the estimation errors in the wall thickness and dielectric constant as well as the target locations with respect to the antenna array. In this paper, we propose a novel technique that enables proper imaging to be performed with unknown wall characteristics. In this technique, the imaging is performed for different sets of the assumed wall parameters at different standoff distances from the wall. For each set of wall parameters, the combined image for different standoff distances is obtained. A focusing metric is then applied to determine the wall characteristics corresponding to the maximum sharpness of the image. The proposed standoff-based imaging technique has several advantages in practical use, including safety, covertness, and rapid acquisition time.