Accession Number : ADD005038

Title :   Acoustic Presence Detection Method and Apparatus.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON D C

Personal Author(s) : Pharo,Lawrence C , Jr

Report Date : 04 Apr 1978

Pagination or Media Count : 7

Abstract : This patent describes a method and means for passively detecting presence of noise radiating devices in a noise environment by determining the number of times per time sample that a received noise signal upwardly crosses a preselected threshold level, comparing this number with the number of upward crossings caused by a standard noise signal or background noise signal, and applying a predetermined ratio criteria. The noise sensors in the detection system may comprise a directional acoustic transducer in combination with an omnidirectional acoustic transducer, and acoustic transducer in combination with an artificially generated noise signal, or a single acoustic transducer. (Author)

Descriptors :   *Patents, *Acoustic detectors, *Target discrimination, Radiated noise, Threshold effects

Subject Categories : Acoustic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE