Accession Number : AD0891305

Title :   The Transmission of 1700-Hz Acoustic Energy over the Block Island-Fishers Island (BIFI) Range.

Descriptive Note : Research rept.,

Corporate Author : NAVAL UNDERWATER SYSTEMS CENTER NEWPORT RI

Personal Author(s) : Sussman, Bernard ; Kanabis, William G.

Report Date : 29 NOV 1971

Pagination or Media Count : 27

Abstract : The BIFI (Block Island-Fishers Island) shallow-water studies were undertaken as part of a program designed to formulate a shallow-water acoustic model suitable for sonar performance prediction. Measurements were made of propagation loss, time smear, and frequency smear over a fixed acoustic range. The results obtained at a frequency of 1700 Hz over a period of approximately six years are presented. Under winter conditions, the propagation loss was found to vary from 92 dB at Sea State 0 to 123 dB at Sea State 5. In the summer, the loss was found to be 108 dB at all sea states from 0 to 3. The time smear studies showed that energy from two or three paths contribute to the received signal. The results of the frequency smear tests were found to be useful in determining dispersion as a function of sea state. (Author)

Descriptors :   *UNDERWATER SOUND), (*SONAR EQUIPMENT, ACOUSTICS), (*SOUND TRANSMISSION, SHALLOW WATER, PROPAGATION, MEASUREMENT, TIME, FREQUENCY, WIND, SONAR SIGNALS, SONAR PULSES, MODEL TESTS, ACOUSTIC RANGES.

Subject Categories : Acoustic Detection and Detectors
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE