Inversion of surface wave dispersion data

The principal goal of the study to be outlined here was to obtain a systematic and practical means of determining structural models of the earth from the observed dispersion of surface waves or from the free oscillation spectrum. This was accomplished through a perturbation scheme which has its basis in Rayleigh's Principle. That is, an initial test structure is assumed and then perturbed until its theoretical dispersion agress with the observed dispersion to within some preselected degree of accuracy. The problem is therefore to determine the necessary perturbations for rapid convergence of the theoretical spectrum to the observed spectrum