Accession Number : ADD007868

Title :   Long Range Listening System.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Ellingson,Herman E

Report Date : 16 Sep 1980

Pagination or Media Count : 7

Abstract : The present invention relates to a system for locating and determining the range to a source of vibration. More particularly, this invention relates to a method and apparatus using correlation techniques in determining the direction and range of a source of sound. Previous devices for determining the direction and distance to a source sound or for locating objects have been of several types. In general, such previous devices have been characterized by the use of triangulation techniques for determining the direction and range to objects or to sources of sound. Also most of the prior art devices are amplitude sensitive and are therefore unable to distinguish the desired signal from local and ambient noise. Many of the prior art devices of this type also have disadvantages resulting from the distortions introduced into transmission of the vibration from the desired source by thermal and other discontinuities in the transmitting medium. The present invention avoids these difficulties by utilizing the correlation of the polarities of the vibrations received from at least two receiving elements.

Descriptors :   *Patents, *Direction finding, *Acoustic arrays, *Clipper circuits, Ambient noise, Correlation techniques, Long range(Distance), Transmitting, Inventions, Vibration, Sources, Sound

Subject Categories : Electrical and Electronic Equipment
      Direction Finding
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE