Through-the-wall microwave imaging: Forward modeling and hybrid inverse-scattering procedures

In this Chapter, an overview of the results achieved by teams from the CNIT research units of the University of Genoa and University of Roma Tre in the framework of through-the-wall imaging is reported. The through-the-wall imaging problem is dealt with through a comprehensive approach, which considers both the solution of the forward-scattering and the inverse-scattering problems. As forward-scattering technique, the Cylindrical Wave Approach is used. It allows the modeling of the response by targets in a trough-the-wall layout, thus providing synthetic data for the validation of imaging approaches. A hybrid two-step approach relying on an inverse-scattering procedure in variable-exponent Lebesgue spaces is adopted for data inversion. In particular, a preliminary reconstruction, which can be obtained through delay-and-sum or truncated singular value decomposition approaches, is used to build the exponent function used in the second step. The reconstructions on experimental data confirm the robustness of the imaging approach in sensing both high-reflecting and low-reflecting targets.