A hybrid perturbational and transformational electromagnetics approach for modeling rough surface scattering problems

Perturbation and transformation electromagnetics methods are hybridized for solving electromagnetic scattering from objects with weakly perturbed surfaces within the context of finite element method. A mesh is generated for smooth surface and a transformation medium layer is designed over the smooth surface by using the coordinate transformation technique. The major advantage of this approach is that if multiple solutions are needed for a set of perturbed surfaces, such as in stochastic or inverse problems, computational load decreases to a great extent because the mesh and global matrix are formed only once, and only the right hand side vector is altered with respect to each of the perturbed surfaces. The approach is validated through numerical simulations.