ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

3aUW12. Shallow-water reverberation measurement and prediction.

James H. Miller

Charles E. Muggleworth

Ching-Sang Chiu

Code EC/Mr, Naval Postgraduate School, Monterey, CA 93943

James F. Lynch

Woods Hole Oceanogr. Inst., Woods Hole, MA 02543

In August 1992, a shallow-water, low-frequency reverberation measurement was made in the Barents Sea utilizing explosive SUS charges as sound sources and a middepth hydrophone as the receiver. The objectives of this work were to analyze the reverberation data from this experiment, compare several theories which have been proposed to model reverberation, develop a technique for estimating the bottom backscattering coefficient in shallow water from single hydrophone acoustic data, and determine the reverberent characteristics of the experimental region. The three-dimensional Hamiltonian Acoustic Ray-tracing Program for the Ocean (harpo) was used as the primary propagation modeling tool. The temporal signal processing consisted of a short-time Fourier-transform spectral estimation method applied to data from the single hydrophone. Chapman's source spectrum model was used. A bistatic Lambert's Law with a frequency-dependent constant was found to fit the data from the experiment. A statistical analysis showed that the reverberation from the Barents Sea experiment was Gaussian to a high degree of confidence.