Merchant Ship Signatures

Abstract

Ship signatures in the form of 1/10 octave band time series and narrowband spectra (0.15 Hz resolution) over the frequency range 10 to 500 Hz are presented. These signatures, detected on a near-bottom receiver in the mid- northeast Pacific Ocean during the CHURCH OPAL exercise, are characterized by greater than 20 dB signal-to-noise ratios over the entire frequency band of 10 to 500 Hz for all merchant ships that approached the receiver site to within 10 nm. The high signal-to-noise ratios resulted from very low noise levels observed in this ocean area. Estimates of source level based on reported ship positions and theoretical propagation loss are 10 dB greater than expected.

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Document Details

Document Type
Technical Report
Publication Date
Aug 18, 1977
Accession Number
ADC014132

Entities

People

  • Jack A. Shooter
  • K. Russell Peterman

Organizations

  • University of Texas at Austin

Tags

Communities of Interest

  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Acoustic Measurement
  • Acoustics
  • Ambient Noise
  • Background Noise
  • Broadband
  • Computations
  • Error Analysis
  • Errors
  • Frequency
  • Frequency Bands
  • Geometry
  • Intellectual Property
  • Network Protocols
  • Physics Laboratories
  • Sound Pressure
  • Spectra
  • Transmission Loss

Readers

  • Acoustical Oceanography.
  • Atmospheric Science/Meteorology
  • Radar Systems Engineering.