ON THE UNDERWATER ACOUSTIC FIELD OF A MOVING POINT-SOURCE .1. RANGE-INDEPENDENT ENVIRONMENT

Hawker [J. Acoust. Soc. Am. 65, 675-681 (1979)] derived the acoustic f ield of a slowly moving point source with constant horizontal velocity in a uniform waveguide. The acoustic field for sources moving with ar bitrary but small horizontal velocities, a more general result, is obt ained in this paper. The wave equation is solved via a temporal Green' s function, and the ensuing acoustic field is naturally expressed in t erms of retarded times familiar in relativity theory and electrodynami cs. This contrasts sharply with conventional solutions in acoustics th at are expressed in terms of contemporary time. For a given source mot ion, the solution may be recast entirely in terms of contemporary time . In the special case of a slowly moving source with constant horizont al velocity, the new solution reduces to that of Hawker. An example is given to illustrate the form of the new solution for a point source i n circular motion in a horizontal plane.