Simultaneous Reconstruction of Dielectric and Perfectly Conducting Scatterers Via $T$-Matrix Method

A
$T$
-matrix method is proposed to solve the mixed boundary inverse scattering problem, i.e., perfect electric conductors (PEC) and dielectric scatterers are simultaneously reconstructed under the two-dimensional transverse magnetic (TM) illumination setting. Both the dipole and monopole elements of the
$T$
-matrix are chosen to accurately describe the scattering behavior of the mixed boundary problem. Criteria of utilizing the monopole element of
$T$
-matrix to distinguish the PEC from dielectric scatterers are presented. Apart from synthetic data, the experimental data from Fresnel dataset is also used to verify the validity of the proposed method, showing that it works well in sub-wavelength setting and is quite robust against noise. The pros and cons of the proposed
$T$
-matrix method are further discussed.