Code 130B, Coastal Systems Sta., Panama City, FL 32407-7001
A way to lift the restriction on transition-matrix-based multiple scattering solutions to obstacles with nonoverlapping circumscribing spheres is investigated. Normally, the rescattering matrix that accounts for interactions between well-separated obstacles is constructed using matrices that translate the positions of the various scattering centers. It is sufficient for these translations to converge if the obstacles are brought no closer than their circumscribing spheres. To lift this restriction when it is desired to bring the obstacles closer, the translations of each scattering center can be replaced by a set of surface integrals over the nearby obstacles. This introduces a dependence on the shape of the obstacles into the rescattering matrix. Numerical calculations to demonstrate this formulation will be presented.