High-Frequency EM Characterization of Through-Wall Building Imaging

A high-frequency asymptotic technique based on the Uniform Geometric Theory of Diffraction (UTD) is employed for building interior imaging. The analysis is implemented using a ray-tracing technique to account for multiple scattering interactions in a building, along with a set of heuristic diffraction coefficients for dielectric wedges and corners. Imaging of the synthetic aperture radar data is carried out by the conventional fast Fourier transform method to transform to the downrange domain, and combined with a coherent near-zone imaging function for cross-range. Comparisons with experimental data for a scaled-down building model are given to demonstrate the suitability and efficacy of our analysis for through-wall building imaging. The UTD ray mechanisms account for the dominant scattering features observed in the image.