Accession Number : ADD008029

Title :   Hydroacoustic Detection System.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Torok,Steve F ; Formica,Vincent A ; Caro,Jasper

Report Date : 19 Feb 1980

Pagination or Media Count : 8

Abstract : Various types of rivercraft propelled by motor, poling, sculling or paddling are found to generate broadband noise having a superimposed low frequency sinusoidal modulation. To detect the presence of such craft, a hydrophone, tethered in a river from a moored subsurface float is connected to a concealed transmitter located on the bank. The detected audio signal is demodulated and filtered. When classification criteria have been satisfied, a gate opens allowing the demodulation information to be processed by a logic circuit, which, if satisfied, causes the hydroacoustic signal to be transmitted over an RF link to a remote receiver station. (author)

Descriptors :   *Patents, *Hydrophones, *Underwater sound signals, Sonar sound analyzers, Logic circuits, Target discrimination, Demodulators, Low pass filters, Automatic gain control

Subject Categories : Acoustic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE