Iterative extended boundary condition method for scattering by objects of high aspect ratios

The limitations of the T-matrix procedure or the extended boundary condition method (EBCM) for wave scattering problems, when used for long slender objects, are due to the shrinking volume over which the incident field is extinguished. The resulting ill-conditioning of the matrices involved makes it impossible to invert them. For nondissipative objects only, we observe that the Reinforced Modified Gram—Schmidt (RMGS) orthogonalization procedure works best of all such unitary approaches investigated, but information about the surface and the internal fields is lost in the process. An alternate approach, called the iterative EBCM (IEBCM) is more general in its scope since it provides convergent surface and internal field values and can also work for dissipative targets. This success of the IEBCM results because it extends the interior volume over which the incident field is extinguished.