GPR Wave Scattering From Complex Objects Using the Semi-Analytic Mode Matching Algorithm: Coordinate Scattering Center Selection

The semi-analytic mode matching (SAMM) algorithm is a quick and efficient computational method that models wave scattering from objects in half spaces. This algorithm relies on appropriately choosing coordinate scattering centers (CSCs) for modal expansions, and successful automation of the CSC selection process is the goal of this paper. CSCs are found for several complex shaped scattering test objects by considering the radius of curvature (ROC) function for each object. The CSCs are found to be largely independent of frequency and located at cusps in the ROC function for scattering objects of modest aspect ratios. Additional CSCs may be required in numbers that are directly proportional to the aspect ratios of more complicated objects, but again, the extra CSC locations are largely independent of frequency. Excellent results are found comparing SAMM and finite-difference frequency domain for 2-D scattering objects that are 0.1-15 wavelengths in size.