Coupled canonical grid/discrete dipole approach for computing scattering from objects above or below a rough interface

Abstract

Abstract-A numerical model for computing scattering from a three-dimensional (3-D) dielectric object above or below a rough interface is described. The model is based on an iterative method of moments solution for equivalent electric and magnetic surface current densities on the rough interface and equivalent volumetric electric currents in the penetrable object. To improve computational efficiency, the canonical grid method and the discrete dipole approach (DDA) are used to compute surface to surface and object to object point couplings, respectively, in ( log ), where is the number of surface or object sampling points. Two distinct iterative approaches and a preconditioning method for the resulting matrix equation are discussed, and the solution is verified through comparison with a Sommerfeld integral-based solution in the flat surface limit. Results are illustrated for a sample landmine detection problem and show that a slight surface roughness can modify object backscattering returns.

Electromagnetic Interactions Analysis Between Two 3-D Scatterers Using the E-Pile Method Combined With the Po Approximation

“…Note that the harmonic time convention e iωt is assumed and suppressed throughout this paper. The plane wave in Equation (1) can be tapered to avoid edge limitations as in [12,13]. To obtain the first coupling integral equation between S 1 and S 2 we use the boundary conditions on scatterer 1 (the object)…”

“…Some methods have been developed for the efficient analysis of composite scattering for a two-dimensional problem (2-D) [1][2][3][4][5][6][7][8][9]. Other examples for a three-dimensional problem (3-D) can be found in [10][11][12][13][14][15][16][17]. However it is important for practical application to study the case of 3-D problem.…”

“…In [12] only small problems are investigated from a fast rigorous method. In [13,14] some assumptions are made on the coupling mechanisms from the four-path model. In [15,16] the electromagnetic scattering of a 3-D object above a 2-D rough surface is studied using the Finite-difference time-domain (FDTD) approach.…”

A Monte-Carlo MPSTD Analysis of Scattering From Cylinders Buried Below a Random Periodic Rough Surface

“…An application of the small perturbation method (SPM) for studying the scattering is presented in [1]. For a numerical simulation of objects above or below a rough surface, integral equations have been formulated and solved by the method of moments (MoM) [2][3][4][5][6][7][8][9]. In particular, itwas employed together with a steepestdescent fast multipole method [4][5][6][7]; and in the analysis presented in [5,8,9], a layered structure was considered.…”

Composite Electromagnetic Scattering From the Plate Target Above a One-Dimensional Sea Surface: Taking the Diffraction Into Account

“…Chiu et al [8] utilized the reciprocity theorem to solve the interaction between a dielectric cylinder and a slightly rough surface. Johnson et al [9][10][11] studied the scattering from an object above or below rough surface using different methods. Pino et al [12] researched the scattering from targets on oceanlike surfaces with the forward-backward method.…”