Accession Number:

ADA609557

Title:

Effect of Internal Waves on Acoustic Interference Structure

Descriptive Note:

Annual rept.

Corporate Author:

WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB

Personal Author(s):

Report Date:

2000-09-30

Pagination or Media Count:

6.0

Abstract:

Our long-term goal is to determine the extent to which a single scalar parameter can characterize observed striations in acoustic intensity patterns. In the second edition of Fundamentals of Ocean Acoustics, Brekhovskikh and Lysanov 1991 introduced the concept of waveguide invariance to a larger audience. They showed how contour plots of acoustic intensity, mapped in range and frequency, would exhibit striations. They defined a parameter beta as a simple function of range, frequency and the slope of the striations, and claimed that this parameter was invariant. They considered a deep-water ocean waveguide problem with a sound speed duct and found -3. In shallow water, they assumed an isovelocity water column and found 1. The objectives of the present work are to estimate beta for more realistic scenarios and to determine the extent to which it is truly an invariant. In particular, the effects of time-varying shallow water internal waves are studied.

Subject Categories:

  • Physical and Dynamic Oceanography
  • Electrical and Electronic Equipment
  • Numerical Mathematics
  • Operations Research
  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE