ASA 125th Meeting Ottawa 1993 May

2aAO7. On the measurement of environmental parameters with a volumetric array of hydrophones using the ambient acoustic field in an anisotropic, range-independent, shallow-water environment.

George B. Smith

Naval Res. Lab., Code 7173, Stennis Space Center, MS 39529-5004

Charles L. Byrne

University of Lowell, Lowell, MA 01854

Howard A. Chandler

Naval Res. Lab., Stennis Space Center, MS 39529-5004

In a previous paper, a high-resolution estimator function that matched ambient acoustic field data from a vertical array of hydrophones to trial environments from a normal mode environmental model was used to estimate the parameters of the environment through which the acoustic energy passed. Shallow-water simulations were used to explore the response of the estimator as a function of several environmental parameters. The general conclusion was that the estimator produced unique and correct estimates for these parameters, but that the method probably would not extend, without modification, to volumetric arrays and anisotropic environments. In this work, it is shown that the inclusion of horizontal aperture (tilted line array) destroys the ability of this technique to distinguish the correct environment even when that environment is isotropic. Methods are explored to generalize the technique so that it works in anisotropic environments with volumetric arrays. [This work was supported by the Office of Naval Research, Program Element 61153N, with technical management provided by the Naval Research Laboratory, Stennis Space Center, MS.]