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

3aUW3. Laboratory measurements of variability in high-frequency bottom backscatter due to thermal fluctuations.

P. Jason White

Kenneth E. Gilbert

Ralph R. Goodman

Appl. Res. Lab. and the Graduate Prog. in Acoust., Penn State Univ., P.O. Box 30, State College, PA 16804

From the World War II era to the present, researchers in ocean acoustics have observed fluctuations (scintillation) in high-frequency backscatter from the seafloor. In general, the fluctuations have been regarded as a nuisance to be gotten rid of if possible. Here the possibility that the fluctuations may actually provide a means to learn more about the scattering process than would be possible with an unchanging signal is considered. Laboratory experiments are described in which known targets are insonified in the presence of artificially induced thermal fluctuations. The resulting backscattered signals are discussed and analyzed within the framework of a weak scatter theory. Possible applications to ocean data are pointed out. [Work supported by ONR and NRL.]