3-DIMENSIONAL ACOUSTIC MODELING BY THE FOURIER METHOD

A three dimensional forward modeling algorithm, allowing arbitrary density and arbitrary wave propagation velocity in lateral and veritcal directions, directly solves the acoustic wave equation through spatial and temporal discretization. Spatial partial differentiation is performed in the Fourier domain. Time stepping is performed with a second-order differencing operator. Three dimensional forward modeling represents a challenge for computer technology. Computation of meaningfully sized models requires extensive calculations and large three-dimensional data sets which must be retrieved and restored during the computation of each time step. The computational feasibility of the Fourier method is demonstrated by implementation on the multiprocessor CRAY X-MP computer system using the large secondary memory of the solid-state storage device (SSD). The similarity of numerical and analytical results indicates sufficient accuracy for many applications. 10 Refs.