Accession Number:

ADA399089

Title:

Sound Propagation Through Anisotropic, Inhomogeneous and Intermittent Turbulence

Descriptive Note:

Final rept. 1 Aug 1998-31 Jul 2001

Corporate Author:

NEW MEXICO STATE UNIV LAS CRUCES DEPT OF PHYSICS

Personal Author(s):

Report Date:

2001-08-01

Pagination or Media Count:

10.0

Abstract:

Three-dimensional models of anisotropic and inhomogeneous spectra of temperature and wind velocity fluctuations in unstable atmospheric boundary layers have been developed, modified or extended. Furthermore, theories of sound propagation through anisotropic, inhomogeneous, and intermittent atmospheric turbulence have been developed. These theories allow consideration of different geometries of sound propagation line-of-sight sound propagation, interference of the direct and ground reflected waves, sound scattering into a refractive shadow zone, and waveguide sound propagation. Using the spectra developed or adopted from the literature, it was shown that anisotropy, inhomogeneity, and intermittency of atmospheric turbulence can significantly affect the statistical moments of a sound field for these geometries. Some of the theoretical results obtained have been verified experimentally. Two related tasks have also been accomplished. First, a new scheme of source localization in the atmosphere by means of acoustic tomography was proposed. The scheme accounts for sound refraction in the atmosphere and allows retrieval of vertical profiles of temperature and wind velocity. Secondly, it was shown that, in many cases, the effects of sound refraction on acoustic remote sensing of wind velocity and the structure parameters of temperature and velocity fluctuations are significant. Algorithms were developed to account for these effects in acoustic remote sensing of the atmosphere.

Subject Categories:

  • Crystallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE