Comparison and application in 3D Matlab-based finite-difference frequency-domain method

• Online Access: http://hdl.handle.net/2047/d10008202

The FDFD electromagnetic model computes wave scattering by directly discretizing Maxwell's equations along with specifying the material characteristics in the scattering volume. No boundary conditions are need except for the outer grid termination absorbing boundary. We use a sparse matrix Matlab code with generalized minimum residue (GMRES) Krylov subspace iterative method to solve the large sparse matrix equation, along with the Perfectly Matched Layer (PML) absorbing boundary condition. The PML conductivity profile employs the empirical optimal value from[4-6]. The sparse Matlab-based model is about 100 times faster than a previous Fortran-based code implemented on the same Alpha-class supercomputer. The 3D FDFD model is easily manipulated, it can handle all types of layer-based geometries if the target region is less than 25% of the total computational space. Several cases have been investigated. The scattered electromagnetic fields due to spherical and elliptic mine-like TNT targets buried in simulated Bosnian soil are computed and compared to reference solutions. The field distribution of dipole in the half space is computed and compared to the half-space Born approximation forward Modeling[8].