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

2pUW10. On measuring sediment/Biot properties in shallow water at moderate to high frequencies.

Ahmed Abawl

W. S. Hodgkiss

W. A. Kuperman

Scripps Inst. of Oceanogr., Univ. of California San Diego, La Jolla, CA 92093-0701

Michael D. Collins

Naval Res. Lab., Washington, DC 20375

A broadband line array is being designed and constructed to study the acoustics of shallow water in the moderate to high-frequency regime. The 64-element array will consist of nested apertures half-wavelength spaced at 4, 8, and 16 kHz with a total bandwidth of 2--20 kHz. The intention is to study both the forward and inverse problem, the latter with respect to sediment properties. The poroelastic parabolic equation [Collins et al., this meeting] is being used for simulations to (1) aid in the design of the array, (2) study the forward problem, and (3) investigate the potential observables with respect to the inverse problem. In particular, it is of great interest as to whether effects related to the Biot description are observable by measuring waveguide propagation. The use of the parabolic equation formulation will allow for a consistent extension to range-dependent environments in a future study. [Work supported by ONR Code 321OA.]