The small slope integral equation method and some applications

Summary form only given. The rigorous solution of scattering by two-dimensional rough surfaces can be performed numerically thanks to advanced numerical methods based on a boundary integral formalism, such as the sparse matrix flat surface iterative approach (SMFSIA). To reduce the large CPU time and memory required, much work has been dedicated to extending the validity of approximate methods. It has been shown (Saillard, M. et al., IEEE Trans. Antennas Propag., vol.52, p.2799-802, 2004) that SMSFIA can be simplified to get a fast approximate method, with lower memory requirements. This method, called the small slope integral equation (SSIE), covers the domain of validity of both the Kirchhoff-tangent plane approximation and the first order small slope approximation. Two applications of SSIE are presented. The advantages of this new model are illustrated, and the original SPM-two scale model and the new SSIE-two scale model are compared.