A novel acceleration algorithm for the computation of scattering from two-dimensional large-scale perfectly conducting random rough surfaces with the forward-backward method

Abstract

The forward-backward method with a novel spectral acceleration algorithm (FB/NSA) has been shown to be an extremely efficient iterative method of moments (MoM) for the computation of scattering from one-dimensional (1-D) perfect electric conducting (PEC) and impedance rough surfaces [1]. The NSA algorithm is employed to rapidly compute interactions between widely separated points in the conventional FB method and is based on a spectral domain representation of source currents and the associated Green's function. For fixed surface roughness statistics, the computational cost and memory storage of the FB/NSA method are ( ) as the surface size increases, where is the total number of unknowns to be solved. This makes studies of scattering from large surfaces, required in low grazing-angle scattering problems, tractable. In this paper, the FB/NSA method is extended to analyze scattering from two-dimensional (2-D) rough surfaces. The NSA algorithm for this case involves a double spectral integral representation of source currents and the 3-D free-space scalar Green's function. The coupling between two spectral variables makes the problem more challenging, and the efficiency improvements obtained for 2-D surfaces are appreciable but not as dramatic as those for 1-D surfaces. However, the computational efficiency of the FB/NSA method for 2-D rough surfaces remains ( ) as one of the surface dimensions increases. Comparisons of numerical results between the conventional FB method and the FB/NSA method for large-scale PEC rough surfaces show that the latter yields identical results to the former with a reduction of CPU time and only a slight increase in memory storage. In addition, the numerical results of FB/NSA method are in good agreement with experimental data obtained from the University of Washington, Seattle, WA.Index Terms-Forward-backward method, novel spectral acceleration algorithm, tough surfaces.

Inversion for refractivity parameters from radar sea clutter

“…Despite the considerable progress in low grazing angle backscatter modeling (see, e.g. the special issue on low-grazing angle backscatter) [Brown, 1998;Toporkov et al, 1999;Voronovich and Zavorotny, 2000;West, 2000;Torrungrueng et al, 2000] this ability is only used indirectly as it will complicate the inversion considerably. The output of linked weather, wave, clutter and propagation models may eventually be brought into the refractivity inversion algorithms.…”

Scattering of electromagnetic waves from two-dimensional randomly rough perfectly conducting surfaces: The full angular intensity distribution

“…This approach has been applied to the study of the scattering of electromagnetic waves from a two-dimensional randomly rough perfectly conducting surface [6,7]. It has been elaborated and made faster by Johnson and his colleagues, resulting in an O(N ) method in some cases, and has been applied to the scattering of electromagnetic waves from a two-dimensional randomly rough perfectly conducting surface [8]. Soriano and Saillard [9] have developed a sparse-matrix flat-surface iterative approach, in which the matrix equations are solved by an iterative Krylov method, the biconjugate gradient stabilized method [10].…”

The E-Pile+smcg for Scattering From an Object Below 2d Soil Rough Surface

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