ASA 125th Meeting Ottawa 1993 May

1aAO6. Predictability of the acoustic field in a shallow water waveguide.

George V. Frisk

Subramaniam D. Rajan

Dept. of Appl. Ocean Phys. & Eng., Woods Hole Oceanographic Inst., Woods Hole, MA 02543

The ability to predict the sound field magnitude and phase in a shallow water waveguide is critically dependent upon accurate knowledge of the acoustic properties of the environment. In this paper, attention is focused on the influence of the geoacoustic properties of the seabed on the predictability of the field. Emphasis is placed on the use of geoacoustic parameter estimates obtained from modal inversion techniques. Some of the research questions to be addressed include: (1) What is the measure of predictability? (2) What are the errors associated with various inversion methods and how do they affect predictability? (3) What is the effect of noise in the data? (4) How useful are geoacoustic parameter estimates obtained over a band of frequencies in predicting the sound field outside that band? Examples using both real and synthetic data will be discussed. [Work supported by ONR.]