ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

2pUW26. Sediment layer structure and composition effects on pulse propagation at the Atlantic generating station (AGS) site.

Rensselaer Polytechnic Inst., Troy, NY 12180-3590

Moshen Badiey

Univ. of Delaware, Newark, DE 19716

William L. Siegmann

Rensselaer Polytechnic Inst., Troy, NY 12180-3590

An investigation of broadband pulse propagation in a shallow water environment is performed using high-order frequency- and time-domain parabolic equation models. High resolution geoacoustical profiles are constructed from cores obtained at the extensively sampled AGS site which lies 5 miles offshore southern New Jersey. These, along with CTD and detailed bathymetric data, are used to model the environment. Acoustic experiments recently conducted at this site [M. Badiey et al., 3593--3604 (1994)] provide broadband acoustic data for comparisons with the modeling predictions. Simulations of transmission loss versus frequency show very good agreement with experimental data over several different propagation tracks. Time-domain simulations are compared with time series of pressure variations generated by the impulsive experimental source along corresponding tracks. Strongly range-dependent mechanisms are observed over short ranges with both models and can be correlated with specific sediment features. A discussion of the modeling results in connection with both environmental and acoustic data sets will be given.