2D Beamforming for Through-the-Wall Microwave Imaging applications

Recently, microwave imaging has received a considerable amount of interest with respect to other imaging techniques. A large number of studies rely on microwaves, as a powerful electromagnetic tool to retrieve physical and electrical properties of penetrable and impenetrable objects. The capability of microwave signals to penetrate light opaque materials and sense distant or inaccessible objects with reasonable spatial resolution makes them attractive for different industrial, civil and medical applications. Our Through-the-Wall Microwave Imaging (TWMI) radar system facilitates us to detect and localize objects behind the wall. Measurements with mono-static radar configuration are made with various sizes of metallic materials inside the room with wooden wall (of known thickness and dielectric constant) using 2D antenna positioning assembly and scattering data is recorded in frequency domain. The simple and fast algorithm for compensation of different wave velocity inside the wall is used and the measured raw data is processed with 2D SAR Beamforming algorithm in time domain to reconstruct the image of the targets behind wall. This paper provides an overview of the basic concepts, foundation prototype system of TWMI, SAR Beamforming algorithm and Comparison of Various matched filter approaches and their effects on quality of image are elaborated in detail.