Accession Number : ADA305987

Title :   Modeled High-Frequency Acoustic Backscattered Levels from Range-Independent and Simplistic Range-Dependent Sand Bottoms.

Descriptive Note : Final rept.,

Corporate Author : NAVAL RESEARCH LAB STENNIS SPACE CENTER MS

Personal Author(s) : Savage, Kristen D. ; Meredith, Roger W.

PDF Url : ADA305987

Report Date : 21 FEB 1996

Pagination or Media Count : 17

Abstract : Results investigating the effects of variable bottom composition on modeled high-frequency backscattered levels are presented for a typical shallow-water, variable bottom (range-dependent) environment. The modeled environment consisted of a single sound speed profile, a flat sea bottom with range-dependent bottom composition, and a smooth, flat sea surface. Coarse-and fine-grained sandy areas were partitioned in range to create range dependence. Bottom backscattering and reflection loss for each partition were obtained from the recent University of Texas high-frequency ocean bottom backscatter model (N. P. Chotiros and F. A. Boyle, J. Acoust. Soc. Am., vol. 96, no. 5, pt. 2, 3264, (1994)). Maximum differences of S dB were discernible between the fine- coarse-fine sand bottom and a range-independent fine-sand bottom for ranges <500 m. The trend and structure of the backscattered levels were nearly identical for both bottom types. In all cases, surface reverberation had a strong impact on the backscattered levels, trends, and structures. (MM)

Descriptors :   *ACOUSTIC SCATTERING, *SONAR, *MINE DETECTORS, *ACOUSTIC COUNTERMEASURES, OCEAN SURFACE, MINE COUNTERMEASURES, GRAIN SIZE, SAND, BACKSCATTERING, SHALLOW WATER, RAY TRACING, REVERBERATION, ACOUSTIC VELOCITY, SOUND PRESSURE, OCEAN BOTTOM SOILS, ACOUSTIC REFLECTION.

Subject Categories : Acoustic Detection and Detectors
      Acoustic Countermeasures
      Underwater Ordnance

Distribution Statement : APPROVED FOR PUBLIC RELEASE