| 摘要 |
The present invention provides a rough surface scattering method and solver for efficiently computing electromagnetic scattered fields resulting from an incident wave (12) being reflected from a surface slowly varying on the scale of the wavelength (10). The wavelength claimed approach to high-frequency scattering is based on the use of expansions of high order in parameter lambd, wavelength of the incident radiation. The resulting high-order expansion approach expands substantially on the range of applicability over low order methods, and can be used in some of the most challenging cases arising in applications. The surface current (14) induced by the incident wave (12) is represented as a high-order high-frequency expansion (20). The surface current ansatz is substituted into the surface current integral equation (22), wherein a surface current series expansion is formed (24) having, a high frequency order. The surface current series expansion includes an oscillatory integral and surface current coefficients. An asymptotic expansion of the oscillatory integral is produced having a Taylor series (26). The Taylor series is evaluated and the surface current coefficients (32) determined. The surface current coefficients are inserted into the surface current series expansion. The surface current series expansion is evaluated to yield the surface current (36). Finally, the scattered field is computed based upon the solved surface current (36).
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