Accession Number : ADA322719

Title :   High-Frequency Acoustic Propagation in a Bottom Boundary Layer: The Acoustic Medium Stability Experiment,

Corporate Author : DYNAMICS TECHNOLOGY INC ARLINGTON VA

Personal Author(s) : Clements, G. M.

PDF Url : ADA322719

Report Date : 1993

Pagination or Media Count : 32

Abstract : The Acoustic Medium Stability Experiment used a horizontal array of hydrophones to measure high-frequency acoustic propagation in a coastal shelf environment. Medium properties varied along the acoustic path, which slanted through a vertically inhomogeneous bottom boundary layer. We apply synthetic spatial aperture filtering to isolate the contribution to acoustic scintillation from medium fluctuations localized at a fixed altitude above the bottom. Using Rytov theory, we compare the filtered acoustic data with direct measurements of medium fluctuations obtained at a corresponding altitude. Analyzing several different examples, we find good agreement between acoustic and temperature-conductivity sensor measurements using a simple, anisotropic model for the three-dimensional spectrum of medium fluctuations.

Descriptors :   *ACOUSTIC MEASUREMENT, MEASUREMENT, STABILITY, HIGH FREQUENCY, COASTAL REGIONS, ENVIRONMENTS, MODELS, ARRAYS, BOUNDARY LAYER, VARIATIONS, THREE DIMENSIONAL, SPECTRA, ANISOTROPY, SOUND TRANSMISSION, HORIZONTAL ORIENTATION, FILTERS, HYDROPHONES, ALTITUDE, SPATIAL FILTERING, ACOUSTIC DATA, BOTTOM, SCINTILLATION, ACOUSTIC DETECTORS, SYNTHETIC APERTURE SONAR.

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE