Experimental measurements of three-dimensional underwater sound propagation over a variable bathymetry laboratory scale model

Experimental measurements have been conducted giving a complete survey of the acoustic field from a point source in a three-dimensional shallow-water environment. The measurements have been conducted over a 1/10 000th scale model of the Santa Lucia Escarpment off the coast of California. The results of the experiment show three-dimensional propagation effects and areas of modal cutoff in the shallow-water regions. In addition, a discontinuity in the acoustic field was observed for propagation over a joint in the model. This observation has implications for localizing changes in seafloor composition from propagation measurements. Numerical predictions of the acoustic field for selected tracks in the survey show good agreement with the experimental results. [Work supported by the Office of Naval Research, Ocean Acoustics Program.]