Modelling Broadband Scattering From Shelled Spheres in a Waveguide

Abstract

The broadband scattering characteristics of a target may be used to distinguish echos from a target of interest from those of clutter. This type of classification is of interest in many sonar applications: ASW, torpedo, surface mines, and diver detection. In a shallow water situation the original sonar pulse and the echo from the target will consist of a sequence of pulses corresponding to the various combinations of incident and backscattered multipath arrivals. For a very shallow target or one close to the seabed, it may be difficult to isolate some of these multipath arrivals. It is expected that these waveguide effects could have a significant effect upon some classifiers. In this paper, we discuss the modelling of scattering of sound from an elastic sphere (shelled, solid, water-filled, etc) which is in a waveguide with an upper surface and a lower seabed. An exact propagation solution is implemented and used to benchmark a ray-expansion solution. The scattered signals for a variety of different sonar pulses and different positions of a spherical target in the waveguide are shown.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 2007
Accession Number
ADA502652

Entities

People

  • John A. Fawcett

Organizations

  • Defence Research and Development Canada

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Weapons Technologies

DTIC Thesaurus Topics

  • Abstracts
  • Bandwidth
  • Broadband
  • Classification
  • Detection
  • Engineering
  • Frequency
  • National Security
  • Scattering
  • Security
  • Sequences
  • Shallow Water
  • Sonar Pulses
  • Specular Reflection
  • Spherical Harmonics
  • Two Dimensional
  • Water

Readers

  • Acoustical Oceanography.
  • Fluid Dynamics.