| dc.description.abstract | Modelling range dependent sound propagation over layered elastic seafloors with high shear speeds has proved to be a difficult problem for many widely used under water acoustic sound propagation models. Recent research and numerical developments have shown that it is possible to obtain accurate results for these types of range dependent environments, however these numerical methods are not as yet available for general use. This article explores the appropriateness of using an equivalent fluid approximation to represent the reflection phenomena associated with a layered elastic seafloor. The focus is on layered calcareous seafloors that are typical of the Australian continental shelf. A complex density approximation is used to best match a fluid plane-wave reflection coefficient to an elastic plane-wave refection coefficient in order to determine the equivalent fluid bottom param-eters. Synthetic signals are computed using Fourier synthesis to compare reflection from the equivalent fluid bottom and the original elastic bottom. The sound exposure level and peak pressure level, commonly used for practical purposes, are computed from these synthetic signals to assess the accuracy of the equivalent fluid ap-proximation. | en_US |
