Application of differential evolution in 2-dimensional electromagnetic inverse problems

Electromagnetic inverse techniques are nondestructive techniques to investigate an unknown region. These techniques use the principle of scattering to determine the number of objects present in the domain, their properties and shapes. However, the scattered field is nonlinear function of the objects´ parameters. Direct search methods prove beneficial in solving such problems. In this paper, we study a two-dimensional domain having dielectric elliptic cylinders of infinite length. We try to estimate the location, contour and relative permittivity of the each of the cylinders. The previous works have majorly contributed to optimization of shapes of cylinders made of perfect electric conductor. Here, we investigate cases of domain having single dielectric elliptic cylinder in different orientations and in noisy/noise-free scenarios. We also present results for a noise-free domain containing two dielectric elliptic cylinders. We use Multiple Signal Classification algorithm to find the exact number of cylinders in the domain and their locations. Then, Differential Evolution is used to estimate the relative permittivities and contours of the cylinders.