A cautionary note on the use of range-dependent propagation models in underwater acoustics

Abstract

A caution is given to the users of range-dependent models that utilize single ocean sound-speed profiles for discrete range intervals. It is shown that, if new profiles are not input every few kilometers, the effect of the discontinuities in the ocean may produce erroneous results. An example illustrates potential errors of as much as 18 dB using the Parabolic Equation Method (PE) to compute propagation through a Gulf Stream ring. It is argued that range interpolation routines should be used to produce closely spaced profiles as a standard part of applying these acoustic propagation codes.