Accession Number : ADP003793

Title :   Multisite Acoustic Location,

Corporate Author : MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB

Personal Author(s) : Walton,R.

Report Date : DEC 1978

Pagination or Media Count : 5

Abstract : Two acoustic arrays 10 km apart are used to locate a sub-sonic aircraft in the horizontal plane. The arrays measure azimuth of sound from the aircraft. If the latter is flying very slowly, it is located at the intersection of straight lines drawn from the sensors in the direction of the azimuths measured at the time the plane is to be located. If the plane is flying faster, the straight lines become curved because of the finite speed of sound, and measurements made over intervals of time must be used instead of measurements made at a single time. But the general picture remains very much the same. The effects of azimuth errors ae similar for slow and fast aircraft, though geometrical diagrams relating error magnitude to aircraft location distort as the aircraft velocity changes. Aircraft height, which causes no error for very slow aircraft, causes only small errors for fast aircraft flying below 1 km. (Author)

Descriptors :   *Acoustic detectors, *Acoustic arrays, *Aircraft detection, Locators, Subsonic flight, Microphones, Azimuth, Errors, Height

Distribution Statement : APPROVED FOR PUBLIC RELEASE