Comparison of Improved Forward Backward Method and Symmetric Successive over Relaxation for computing the scattering from randomly rough lossy surfaces

The Improved Forward Backward Method and Symmetric Successive over Relaxation (SSOR) method are proposed to compute electromagnetic (EM) scattering from 1-D dielectric rough surfaces. In addition the Spectral Acceleration (SA) technique is applied to reduce the computational complexity of each matrix-vector product from O(N²) to O(N). The proposed methods are referred as IFBM-SA and SSOR-SA. They are compared with the FBM-SA which is a well-known and effective method in computing the scattering from randomly rough lossy surfaces in terms of convergence rate and run time. FBM-SA is shown to be a special case of SSOR-SA where the relaxation parameter is unity. The numerical analysis demonstrates that IFBM-SA has a higher convergence rate than the SSOR-SA and FBM-SA.