Accession Number:

AD0755696

Title:

The Coherence of Signals, Noise and Reverberation in the Sea

Descriptive Note:

Corporate Author:

NAVAL ORDNANCE LAB WHITE OAK MD

Personal Author(s):

Report Date:

1972-11-01

Pagination or Media Count:

22.0

Abstract:

Separated hydrophones in the sea show varying degrees of coherence, or waveform similarity, depending on separation, frequency, and kind of sound observed. Over the past ten years we have measured the phase coherence of different kinds of signals, noise and reverberation between vertically separated hydrophones. Such information is basic for the optimum design of arrays. This paper summarizes these measurements. When plotted against normalized separation, the coherence as measured by the clipped correaltion coefficient is found to lie, as it should, between the value of unity for a plane wave and a curve for isotropic noise it depends on the vertical angle within which the sound arrives at the two hydrophones. The most coherent sounds observed were signals in covergence zones the least coherent, the reverberation received from great depths in the deep sea

Subject Categories:

  • Acoustic Detection and Detectors
  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE