Underwater Acoustic Scatter from a Model of the Arctic Ice Canopy

Abstract

When low frequency underwater sound interacts with the Arctic ice cover, not only will it be reflected from the plane and scattered in all directions from roughness elements, but it will also be diffracted at leads and reradiated from flexural waves in the ice. These phenomena have been studied in an anechoic tank by pulse transmission from an underwater point source to a series of large floating acrylic plate models, each representing a different type of ice cover. The flexural wave speed, the plate and lead dimensions and the acoustic roughness are accurately scaled, and the specific acoustic impedance contrast is approximately modeled by the selection of the acrylic material. The physical contributors to the gross reflection coefficient and backscattering strength are identified and compared for models of a plane ice layer, an Arctic ice pressure ridge, edges of leads, and a rubble field of ice. Keywords: Underwater Acoustics; Scatter, Backscatter; Arctic Ice; Reflection Coefficient; Flexural Waves; Theses.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1986
Accession Number
ADA176654

Entities

People

  • Kevin R. Johnson
  • Patrick L. Denny

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Acoustic Impedance
  • Acoustic Properties
  • Acoustics
  • Backscattering
  • Diffraction
  • Forward Scattering
  • Geometry
  • Grazing Angles
  • Measurement
  • Physical Properties
  • Physics Laboratories
  • Processing Equipment
  • Reflection
  • Research Facilities
  • Scattering
  • Signal Processing
  • United States

Fields of Study

  • Physics

Readers

  • Acoustical Oceanography.
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Polar and Arctic Studies