Observations of Fluctuation of Transmitted Sound in Shallow Water

R. J. Urick, G. R. Lund, David Bradley

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

An 1120 Hz CW sound source was placed on the bottom in 60 ft of water off Fort Lauderdale, Florida. The sound from the source was monitored by a number of hydrophones placed on the bottom about 5000 ft away in the direction parallel to the shore. The received sound was observed to be unsteady, and to exhibit fluctuations of two kinds. One fluctuation had a periodicity of 3 to 4 sec, the same as that of the sea and swell in a 5 to 15 kt wind, and was accompanied by phase difference fluctuations between hydrophones. The other had a periodicity the same as that of the tides, with fades of 15 dB or more occurring at the times of low water. This tidal variation has been accounted for by both a simplified form of normal mode and by image theory in terms of the interference between the first few modes or rays responsible for the transmission.

Original languageEnglish (US)
Pages (from-to)683-690
Number of pages8
JournalJournal of the Acoustical Society of America
Volume45
Issue number3
DOIs
StatePublished - 1966

Fingerprint

shallow water
acoustics
hydrophones
periodic variations
tides
water
rays
interference
Fluctuations
Water
Sound

All Science Journal Classification (ASJC) codes

  • Acoustics and Ultrasonics
  • Arts and Humanities (miscellaneous)

Cite this

Urick, R. J. ; Lund, G. R. ; Bradley, David. / Observations of Fluctuation of Transmitted Sound in Shallow Water. In: Journal of the Acoustical Society of America. 1966 ; Vol. 45, No. 3. pp. 683-690.
@article{798cb64d13234e0f8896bef9cad97da6,
title = "Observations of Fluctuation of Transmitted Sound in Shallow Water",
abstract = "An 1120 Hz CW sound source was placed on the bottom in 60 ft of water off Fort Lauderdale, Florida. The sound from the source was monitored by a number of hydrophones placed on the bottom about 5000 ft away in the direction parallel to the shore. The received sound was observed to be unsteady, and to exhibit fluctuations of two kinds. One fluctuation had a periodicity of 3 to 4 sec, the same as that of the sea and swell in a 5 to 15 kt wind, and was accompanied by phase difference fluctuations between hydrophones. The other had a periodicity the same as that of the tides, with fades of 15 dB or more occurring at the times of low water. This tidal variation has been accounted for by both a simplified form of normal mode and by image theory in terms of the interference between the first few modes or rays responsible for the transmission.",
author = "Urick, {R. J.} and Lund, {G. R.} and David Bradley",
year = "1966",
doi = "10.1121/1.1911441",
language = "English (US)",
volume = "45",
pages = "683--690",
journal = "Journal of the Acoustical Society of America",
issn = "0001-4966",
publisher = "Acoustical Society of America",
number = "3",

}

Observations of Fluctuation of Transmitted Sound in Shallow Water. / Urick, R. J.; Lund, G. R.; Bradley, David.

In: Journal of the Acoustical Society of America, Vol. 45, No. 3, 1966, p. 683-690.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Observations of Fluctuation of Transmitted Sound in Shallow Water

AU - Urick, R. J.

AU - Lund, G. R.

AU - Bradley, David

PY - 1966

Y1 - 1966

N2 - An 1120 Hz CW sound source was placed on the bottom in 60 ft of water off Fort Lauderdale, Florida. The sound from the source was monitored by a number of hydrophones placed on the bottom about 5000 ft away in the direction parallel to the shore. The received sound was observed to be unsteady, and to exhibit fluctuations of two kinds. One fluctuation had a periodicity of 3 to 4 sec, the same as that of the sea and swell in a 5 to 15 kt wind, and was accompanied by phase difference fluctuations between hydrophones. The other had a periodicity the same as that of the tides, with fades of 15 dB or more occurring at the times of low water. This tidal variation has been accounted for by both a simplified form of normal mode and by image theory in terms of the interference between the first few modes or rays responsible for the transmission.

AB - An 1120 Hz CW sound source was placed on the bottom in 60 ft of water off Fort Lauderdale, Florida. The sound from the source was monitored by a number of hydrophones placed on the bottom about 5000 ft away in the direction parallel to the shore. The received sound was observed to be unsteady, and to exhibit fluctuations of two kinds. One fluctuation had a periodicity of 3 to 4 sec, the same as that of the sea and swell in a 5 to 15 kt wind, and was accompanied by phase difference fluctuations between hydrophones. The other had a periodicity the same as that of the tides, with fades of 15 dB or more occurring at the times of low water. This tidal variation has been accounted for by both a simplified form of normal mode and by image theory in terms of the interference between the first few modes or rays responsible for the transmission.

UR - http://www.scopus.com/inward/record.url?scp=79956149223&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79956149223&partnerID=8YFLogxK

U2 - 10.1121/1.1911441

DO - 10.1121/1.1911441

M3 - Article

AN - SCOPUS:79956149223

VL - 45

SP - 683

EP - 690

JO - Journal of the Acoustical Society of America

JF - Journal of the Acoustical Society of America

SN - 0001-4966

IS - 3

ER -