A theoretical method for the prediction of underwater explosion pulses at caustics

Abstract

Our concern [Refs. 1 and 2J is with the effect of refraction on the long range propagation of underwater explosion shock waves. Here, as with acoustic sources, ray tracing can be used to predict refraction effects. From the divergence or convergence of rays, an amplification factor can be calculated. This is defined as the square root of the ratio of the cross sectional area between rays at a given point assuming spherical spreading to the cross sectional area between rays at the same point when the actual sound velocity profile is specified. We can then multiply the pressure history expected at a given point if no refraction occurred by the appropriate amplification factor. This then gives us the pressure history expected at that point when refraction is accounted for.