Modelling of Pulse Propagation in Layered Media Using a New Fast Field Program

Abstract

Numerical modelling of acoustic pulse propagation in stratified solid media is often found to be impractical due to the comprehensive calculations involved. Here a new numerical model, of the fast field type, is presented. Instead, of using the Thomson-Haskell matrix method, as done in earlier models of the same type, the depth-separated wave equation is solved by a numerical technique very similar to that used in finite element programs. The speed improvement has been considerable, especially in cases with many sources and receivers. The model has been implemented on an FPS164 array processor and used for analysis of seismic pulse propagation in a shallow water environment and reflection of pulsed ultrasonic beams from a fluid-solid interface.