Retrieval of Subsurface Properties of Layered Dielectric Structures Using Hybrid Global and Local Optimization

In this paper, we present an inversion scheme to retrieve subsurface properties of layered dielectric structures with random slightly rough interfaces. We use the small perturbation method in the forward model. To solve the inverse-scattering problem, we utilize a novel global optimization technique, which takes advantage of the speed of local optimization while ensuring convergence to a global minimum. More specifically, by modifying the perturbation scheme in the simulated annealing method using a non-linear simplex search algorithm, we enhance the performance of global search by choosing effective perturbation directions. We have demonstrated the strength of the method in solving the inverse-scatting problems by some numerical results.