Monte Carlo simulation of electromagnetic scattering from two-dimensional random rough surfaces (original) (raw)
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IEEE Transactions on Geoscience and Remote Sensing, 1998
A new technique, the steepest descent-fast multipole method (SDFMM), is developed to efficiently analyze scattering from perfectly conducting random rough surfaces. Unlike other prevailing methods, this algorithm has linear computational complexity and memory requirements, making it a suitable candidate for analyzing scattering from large rough surfaces as well as for carrying out Monte Carlo simulations. The method exploits the quasiplanar
2016
Electromagnetic scattering by two dimensional random rough surface is studied. After generating a two-dimensional rough surface, the joint probability density function of the surface height and slope is computed and used to determine the electromagnetic scattering field. The ray-tracing base model is utilized. Also Monte-Carlo method is employed to transform an infinite to a finite integration. In this paper two case studies have been performed and compared with each other. For the first case, we worked on the suggested method on [1] to find the 2D electromagnetic scattering field. In this, the authors for their future work have proposed a way to solve the 2D scattering problem. Their method consisted of computing the PDF of the scattering field in x → and y → direction and use them to determine the scattered field. For second case we discuss our proposed method which is to use the joint PDF of surface height and slope instead of the one proposed in [1] to determine the 2D scatterin...
Monte Carlo calculation for electromagnetic-wave scattering from random rough surfaces
Physical Review Letters, 1984
A Monte Carlo calculation for light intensities scattered from a random Gaussiancorrelated surface is presented for the first time. It is shown that small randomness on a grating surface can considerably change the intensities and, in particular, -the surface polariton resonances. These results should be used to check perturbation-theory calculations.
Fast algorithm for the analysis of scattering by dielectric rough surfaces
Journal of the Optical Society of America A, 1998
A novel multilevel algorithm to analyze scattering from dielectric random rough surfaces is presented. This technique, termed the steepest-descent fast-multipole method, exploits the quasi-planar nature of dielectric rough surfaces to expedite the iterative solution of the pertinent integral equation. A combination of the fastmultipole method and Sommerfeld steepest-descent-path integral representations is used to efficiently compute electric and magnetic fields that are due to source distributions residing on the rough surface. The CPU time and memory requirements of the technique scale linearly with problem size, thereby permitting the rapid analysis of scattering by large dielectric surfaces and permitting Monte Carlo simulations with realistic computing resources. Numerical results are presented to demonstrate the efficacy of the steepest-decent fastmultipole method.
Scattering of Electromagnetic Waves from Two-Dimensional Randomly Rough Penetrable Surfaces
Physical Review Letters, 2010
We present a method giving the bi-static scattering coefficient of two-dimensional (2-D) perfectly conducting random rough surface illuminated by a plane wave. The theory is based on Maxwell's equations written in a nonorthogonal coordinate system. This method leads to an eigenvalue system. The scattered field is expanded as a linear combination of eigensolutions satisfying the outgoing wave condition. The boundary conditions allow the scattering amplitudes to be determined. The Monte Carlo technique is applied and the bi-static scattering coefficient is estimated by averaging the scattering amplitudes over several realizations. The random surface is represented by a Gaussian stochastic process. Results are compared to published numerical and experimental data. Comparisons are conclusive.
Journal of the Optical Society of America A, 2001
The sparse-matrix-flat-surface iterative approach has been implemented for perfectly conducting surfaces and modified to enhance convergence stability and speed for very rough surfaces. Monte Carlo simulations of backscattering enhancement using a beam decomposition technique are compared with millimeter-wave laboratory experimental data. Strong but finite conductivity for metals or thin skin depth for dielectrics is simulated by an impedance approximation. This gives rise to a nonhypersingular integral equation derived from the magnetic field integral equation. The effect of finite conductivity for a metal at visible wavelengths is shown.
A Detailed Study of the Scattering of Scalar Waves from Random Rough Surfaces
Optica Acta: International Journal of Optics, 1981
A multiple scattering theory of scalar waves from random rough surfaces is presented. By using the Ewald-Oseen extinction theorem the scattering integral equation is solved by means of an expansion in powers ( being the standard deviation of the corrugation). Values of the ...
Radio Science, 1998
The forward-backward method has been shown to be an effective iterative technique for the computation of scattering from one-dimensional rough surfaces, often converging rapidly even for very large surface heights. However, previous studies with this method have computed interactions between widely separated points on the surface exactly, resulting in an O(N 2) computational algorithm that becomes intractable for large rough surface sizes, as are required when low grazing incidence angles are approached. An acceleration algorithm for more rapidly computing interactions between widely separated points in the forward-backward method is proposed in this paper and results in an O(N) algorithm with increasing surface size. The approach is based on a spectral domain representation of source currents and the Green's function and is developed for both perfectly conducting and impedance boundary surfaces. The method is applied in a Monte Carlo study of low grazing incidence backscattering from very rough (up to 10 m/s wind speed) ocean-like surfaces at 14 GHz and is found to require only a small fraction of the CPU time required by other competing methods; such as the banded matrix iterative approach/canonical grid and fast multipole methods. 1. Introduction Several efficient numerical methods for the computation of scattering from one-dimensional rough surfaces have been proposed in recent years [Chan et
2004
A fast algorithm for reconstructing the profile of random rough surfaces using electromagnetic scattering data is presented. The algorithm is based on merging a fast forward solver and an efficient optimization technique. The steepest descent fast multipole method (SDFMM) is used as the three-dimensional (3-D) fast forward solver. A rapidly convergent descent method employing a “marching-on” strategy for processing multi-frequency and multiincidence angle data is introduced to minimize an underlying cost function. The cost function represents the error between true (synthetic) and simulated scattered field data. Several key issues impact the accuracy in reconstructing the rough profile are examined in this work, e.g., the location and number of receivers, the incident and scattered directions, the surface roughness, and details regarding the manner in which sensitivity information is computed in the inversion scheme. The results show that using the multiple-incidence (one angle at a...