Acoustic Wave Dispersion and Scattering in Complex Marine Sediment Structures

Abstract

Major challenges in testing dispersion theories against measured data include separating the competing effects of structures that occur in virtually all natural marine sediments including discrete layering, gradients (sound speed, attenuation and density), shear waves, interface roughness, sediment volume heterogeneities (sub-wavelength scale), lateral variability (many wavelength scale) and anisotropy. All of these effects exhibit their own frequency dependence and if ignored, can badly bias dispersion estimates. One of the competing effects, sediment volume scattering, is important not only for establishing the correct frequency dependence of the attenuation, but also crucial for understanding long-range reverberation prediction. Recent evidence has suggested that sediment volume scattering is a dominant mechanism for controlling the frequency dependence of reverberation. The long-term goal of the research is to substantively improve understanding of the physical mechanisms that control propagation and scattering in the seabed.

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Document Details

Document Type
Technical Report
Publication Date
Mar 21, 2018
Accession Number
AD1049148

Entities

People

  • Charles W. Holland

Organizations

  • Pennsylvania State University Applied Research Laboratory

Tags

Communities of Interest

  • Autonomy

DTIC Thesaurus Topics

  • Acoustic Waves
  • Acoustics
  • Autonomous Underwater Vehicles
  • Complex Systems
  • Dispersions
  • Doppler Effect
  • Frequency
  • Geometry
  • Heterogeneity
  • Measurement
  • Reflection
  • Roughness
  • Scattering
  • Seabed
  • Secondary Waves
  • Three Dimensional
  • Waves

Readers

  • Acoustical Oceanography.
  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Educational Psychology