AN ANALYSIS OF UNDERWATER ACOUSTIC BACKSCATTERING.

Abstract

Experimental observations are conducted in a 4 x 4 x 10 feet steel tank filled with fresh water and equipped with fans for generating a wind driven statistical surface. A pulse-gate technique is employed which utilizes a single transducer. Backscatter pulse data is processed to yield backscattered power vs. incident angle and backscattered power spectral density. Two analytical models are postulated to predict backscattering as a function of surface conditions. The first model considers the surface to be made up of a finite number of random length facet scatters, each tilted at a random angle. Comparisons with the model tank data indicate that this model is unrealistic for measuring backscatter and is inadequate since it cannot predict power spectral density. Therefore, a continuous model is postulated which considers the surface to be made up of differential facets with dipole scattering patterns. Statistical averaging of the product of the backscattered signal and the time delayed signal yields the backscatter autocorrelation function. Comparisons between the literature, the models, and the model tank data are made and the useful ranges of the models are determined. (Author)

Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1966
Accession Number
AD0648825

Entities

People

  • L. R. Leblanc

Organizations

  • University of Rhode Island

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Autocorrelation
  • Backscattering
  • Electromagnetic Scattering
  • Forward Scattering
  • Fresh Water
  • Literature
  • Nuclear Reactions
  • Nuclear Scattering
  • Observation
  • Scattering
  • Surface Properties
  • Transducers
  • Water

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Regression Analysis.