Accession Number:

ADA231583

Title:

Application of the Finite Element Method to Random Rough Surface Scattering with Neumann Boundary Conditions

Descriptive Note:

Master's thesis

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s):

Report Date:

1990-01-01

Pagination or Media Count:

51.0

Abstract:

Scattering from a one-dimensional rough surface with Gaussian roughness spectrum is analyzed using a finite element formulation. The method is applied to Monte Carlo simulations satisfying Neumann boundary conditions. Finite element results are compared with results obtained by solving an integral equation. Convergence of the method is verified by varying the number of nodal points in the first order, triangular mesh. Results are in excellent agreement with tapered wave integral equation solutions for large surface length after averaging over realizations. Finite element advantages in time and memory storage are presented for the examples discussed. Comparisons with the Kirchoff approximation and small perturbation theory within their respective regions of validity are also presented. Additionally, analysis of the effects of decreasing surface length on incoherent scattering results of the finite element method is accomplished to investigate the methods likely advantages for large-scale scattering problems. Numerical results of scattering are represented in terms of the normalized bistatic scattering cross section.

Subject Categories:

  • Numerical Mathematics
  • Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE