Statistical Characterization of Seafloor Roughness

Abstract

Topography of the seabed can strongly affect underwater sound propagation in the ocean. Seafloor features fall into 3 overlapping categories according to size; large features that block propagation, intermediate features that act primarily as sloping bottoms, and small-scale features that act as scatterers. This paper presents statistical parameters of bottom topography for the 2 latter categories. Spatial wavenumber spectra of ocean bottom and subbottom roughness are determined from narrow-beamwidth echosounding and seismic reflection profiling. The spectra are compared to the expression P(K) = CK to the minus b power where P(K) is the power spectral density, C is a proportionality constant, K is the wavenumber, and b is a constant that characterizes the class of roughness. The parameter b is often assumed to be 3; however, this study shows that b can range from about 1 to 5. Topographic samples were found to have probability density functions which were both non- Gaussian and Gaussian. It is suggested that a first-order roughness data base include band-limited RMS roughness; K sub 1 and K sub 2 (the wavenumbers of the estimate); b; sediment type; physiographic province, water depth, and location. Reprints.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1984
Accession Number
ADA201155

Entities

People

  • J. E. Matthews
  • Jonathan M. Berkson

Organizations

  • United States Naval Research Laboratory

Tags

DTIC Thesaurus Topics

  • Acoustics
  • Databases
  • Diffraction
  • Frequency
  • Fresnel Zones
  • Measurement
  • North Pacific Ocean
  • Oceans
  • Pacific Ocean
  • Power Spectra
  • Probability
  • Probability Density Functions
  • Reflection
  • Scattering
  • Seabed
  • Sonar
  • Topography

Readers

  • Acoustical Oceanography.
  • Oceanography.
  • Statistical inference.