Transformation Method for Results from a Cartesian Finite Element ParabolicEquation Calculation to Spherical Waves

摘要

A finite element parabolic equation code has been linked to an extended boundarycondition (T-matrix) multiplication routine to provide a basin scale active acoustic simulation. The transformation from Cartesian finite elements to spherical waves was achieved by Fourier analyzing the incoming vertical finite element field in sections to determine the directions and amplitudes of various components. These were then integrated over all sections into a spherical representation, using the properties of spherical harmonics. The incoming waves were then scallered using a standard T-matrix multiplication routine. The outgoing waves were evaluated at a new set of points to generate the starter for another finite element parabolic equation calculation.