Linear and nonlinear iterative scalar inversion of multi-frequency multi-bistatic experimental electromagnetic scattering data

This paper reports results obtained by linear and nonlinear iterative scalar inversion of experimental electromagnetic scattering data sets for different targets. The applied inversion schemes are a linear diffraction tomography algorithm and three nonlinear iterative methods. Two domain integral equation based methods, namely a modified gradient in field algorithm and a contrast source inversion method, are used. The third method is a real-coded genetic algorithm based on a boundary integral equation formulation. Inversion results are presented and compared for dielectric targets (penetrable scatterers) and metallic targets (perfect scatterers) using measurements for the transverse magnetic polarization case acquired in an anechoic chamber.