A comparison of two computer models of sound propagation for a wedge shaped ocean over a penetrable bottom

Abstract

The problem of determining the acoustic pressure in a wedge shaped wave guide is examined. Two computer models, one using the method of images, the other using coupled normal modes, are compared. This comparison is over the benchmark wedge of the Acoustic Society of America. Three scenarios were examined: isovelocity water over a pressure release bottom, isovelocity water over a penetrable, lossless bottom, and isovelocity water over a penetrable, lossy bottom. In all cases good agreement was seen between both models, with some differences due to a rigid subbottom in the normal mode model. The strengths and weaknesses of each model is examined. An analytic solution in normal modes of the waveguide with a pressure release surface, rigid bottom, and a discontinuous speed of sound profile is presented. A brief history of research into the wedge problem is included in the introduction. Acoustic models, Computer models, Normal mode determination, Method of images