REVISED INTEGRATION METHODS IN A GALERKIN BOR PROCEDURE

Abstract

Several relatively simple numerical changes improve the speed and accuracy of the early Mautz and Harrington discretization procedure for boundary element method calculations of scattering from axially symmetric bodies. This method is still in common use in programs such as CICERO and GRMBOR. For a fixed set of geometry points, changes in the azimuthal (o) integration reduce computer time, especially when lossy materials are involved. Changes in the integration along the generating curve (t) improve accuracy. The most interesting of these is the use of the equal area rule from parallel wire modeling of solid surfaces to answer the old question of the optimal constant for dealing with an integrable singularity in some of the t integrals. Some of these changes are applicable to a variety of integral equations and boundary conditions. Most of them can be implemented with little programming effort. Tests are shown for difficult cases involving spheres, and Mie series calculations are used for comparison. [Vol. 10, No. 2 (1995), pp 5-16]