Tomographic Measurements of Barotropic Motions

Abstract

In 1983, continuous acoustic transmissions centered at 133 Hz and with a resolution of 60 ms were transmitted for five days from Oahu to the coast of Northern California (4000 km range). A maximum likelihood estimate of the change in acoustic travel time (based on phase) between received pulses is used to estimate barotropic fluctuations. Analysis of the resulting time series reveals resonant oscillations at nontidal frequencies in the Northeast Pacific. Some of the periods of the resonant oscillations are consistent with theory (Platzman, Curtis, Hansen, and Slater, 1981). A Wiener filter is formulated for estimating the barotropic tides from a basin scale tomographic array. Error analyses indicate an ability to estimate barotropic currents and surface displacements with errors less than 0.01 cm/s and 1 cm, respectively, over a large portion of the Northeast Pacific Ocean. Keywords: Acoustic tomography, Travel time, Ocean models, Ocean tides, Barotropic fluctuations, Spectral analysis, Ocean basins, Underwater sound transmission. Theses.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1987
Accession Number
ADA208843

Entities

People

  • Paul J. Bushong

Organizations

  • Woods Hole Oceanographic Institution

Tags

Communities of Interest

  • Energy and Power Technologies
  • Space
  • Weapons Technologies

DTIC Thesaurus Topics

  • Acoustic Tomography
  • California
  • Cross Correlation
  • Engineering
  • Error Analysis
  • Errors
  • Estimators
  • Filters
  • Frequency
  • Matched Filters
  • Measurement
  • Oceanography
  • Oceans
  • Oscillation
  • Signal Processing
  • United States
  • United States Naval Academy

Readers

  • Coastal Oceanography
  • Oceanography.
  • Optical Physics and Photonics.