Modeling a spiral wave front source in an ocean environment

Abstract

A spiral wave front source generates a pressure field which has a phase that depends on the azimuthal angle at which it is measured [J. Acoust. Soc. Am. 129(6), (2011)]. This type of source can be used in conjunction with a reference source to form a navigation beacon. A remote receiver can determine the direction to the beacon from the phase difference between the pulses transmitted from each of the sources. To determine the accuracy of this navigation technique, it is necessary to model the output of the spiral wave front source in ocean environment. To this end, the spiral wave front analogue of the acoustic point source is examined and is shown to be related to the point source through a simple transformation. This makes it possible to transform the point source solution in a particular ocean environment into the solution for a spiral source in the same environment. This transformation is applied to simple cases, such as reflection from the sea surface, as well as to the more general case of propagation in a horizontally stratified waveguide. [Work supported by the Office of Naval Research.]