Numerical and laboratory modeling of propagation over troughs and ridges

Abstract

Numerical predictions and laboratory measurements of the underwater sound pressure field are presented for four different bathymetry profiles: a range-independent control case, two trough shapes, and a ridge. Differences between numerical and experimental transmission loss are shown to be consistent with small differences in assumed water depth and these differences are used to invert the measured data to extract the actual bathymetry, using a simple explicit method applicable to slowly varying but otherwise arbitrary bottom profiles. In retrospect, measurement of the position of interference fringes provides a means of inferring the water depth profile.