An accelerated boundary integral equation scheme for propagation over the ocean surface

Abstract

[1] In two recent papers, C. L. Rino, H. Ngo and V. Kruger (RNK) proposed a novel scheme for tropospheric propagation over one-dimensional (1D) terrain or ocean surfaces. This scheme is based on a boundary integral equation (BIE) formalism, the iterative solution of which is carried out efficiently via the method of ordered multiple interactions (MOMI). An important merit of the RNK scheme is the fact that, being a BIE-based model, it rigorously accounts for the effect of the multiple-scale ocean surface roughness on the propagated field. In their most recent paper, C. L. Rino and V. Kruger suggested that the accelerated version of MOMI proposed by H.-T. Chou and J. T. Johnson (MOMI/ CJ) could substantially enhance the efficiency of their scheme. Motivated by this suggestion, this paper proposes a combined RNK/CJ algorithm for propagation over finitely conducting (FC) ocean surfaces. While maintaining its accuracy, the proposed scheme enhances the computational efficiency of the rigorous RNK model by reducing the number of mathematical operations needed in the iterative solution of the governing BIE.INDEX TERMS: 6964 Radio Science: Radio wave propagation; 0659 Electromagnetics: Random media and rough surfaces; 0644 Electromagnetics: Numerical methods; KEYWORDS: wave propagation, rough surface scattering, integral equation methods, fast numerical algorithms Citation: Awadallah, R. S., M. T. Lamar, and J. R. Kuttler, An accelerated boundary integral equation scheme for propagation over the ocean surface,

Fast and Accurate Algorithm for Electromagnetic Scattering From 1-D Dielectric Ocean Surfaces

“…Once (5) and (6) are solved for the surface quantities, the scattered field can be calculated via the far-field form of the formula (9) The normalized scattering cross section (NSCS) in the direction is given by (10) In (10), is the power incident on the mean plane of the rough surface. In order to eliminate the edge effects in the MoM solution, the tapered incident field suggested in [3] was used in this paper.…”

“…Many iterative procedures for solving the rough surface scattering problem have been reported in the literature. Among these are the generalized conjugate gradient (GCG) method ( [5], [6]) the generalized conjugate residual (GCR) method [7] and the method of ordered multiple interactions (MOMI) ( [8], [9]). All these iterative schemes require the repeated multiplication of the MoM matrix with the different iterates of the surface current vector.…”

Low-Grazing Angle Propagation and Scattering Above the Sea Surface in the Presence of a Duct Jointly Solved by Boundary Integral Equations

“…In [5]- [8], the BIE method is applied for the scattering from rough sea surfaces at grazing angles without ducting effects. In [9], an accelerated BIE scheme is proposed for propagation over the ocean surface.…”

Brief review on PE method application to propagation channel modeling in sea environment

“…The 2D PE (1) loses validity when problems involving propagation over terrain with steep transverse gradients leading to substantial lateral (cross-range) effects (diffraction, scattering, depolarization) are to be solved [38,56]. Given the rigorous 3D modeling of those scenarios with accounting for an inhomogeneous troposphere is extremely difficult (including their treatment with Integral Equation methods as well, see the discussion in [98]), an alternative may be searched for in pseudo-3D PE applications. The full treatment of those problems requires a 3D vector PE [87,[99][100][101].…”