Study of Environmental Influences on Phase Fluctuations and Their Effect on Synthetic Aperture Sonars (SAS)

Abstract

An acoustic propagation experiment designed to investigate how Synthetic Aperture Sonar (SAS) is affected by the underwater environment was conducted off the eastern U.S. coastline near Marthas Vineyard in August 1996. This report describes the effect of this shallow-water, underwater environment on the phase of propagating acoustic signals. This experiment made measurements of acoustic ping-to-ping phase fluctuations at a frequency of 20 kHz. These fluctuations were measured using a submersible tow body on which were mounted two acoustic arrays that received pulses transmitted once per second from sources that were mounted on two stationary, spatially separated towers. The phase fluctuations are calculated after correcting for any phase errors induced by the motion of the tow body. The results showed that the use of SAS techniques in this environment would be, at best, marginal at 20 kHz. The measured phase fluctuations led, in some cases, to theoretically calculated SAS beam patterns that were nearly omnidirectional.

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Document Details

Document Type
Technical Report
Publication Date
Mar 25, 1999
Accession Number
ADA362278

Entities

People

  • Edward J. Yoerger
  • J. S. Stanic
  • Timothy H. Ruppel

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Materials and Manufacturing Processes
  • Sensors

DTIC Thesaurus Topics

  • Accuracy
  • Acoustic Propagation
  • Acoustic Signals
  • Acoustics
  • Arrays
  • Coordinate Systems
  • Data Analysis
  • Environment
  • Flight Paths
  • Frequency
  • Linear Arrays
  • Measurement
  • Military Research
  • Sonar
  • Synthetic Aperture Sonar
  • Water
  • Waves

Fields of Study

  • Physics

Readers

  • Acoustical Oceanography.