Accession Number : ADD004028

Title :   Sequential Observer Multi-Functional Friend Accept Decider.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON D C

Personal Author(s) : Bishop,Walton B

Report Date : 26 Apr 1977

Pagination or Media Count : 8

Abstract : In a military environment, it is essential to determine whether an approaching aircraft or other vehicle is a friend or an enemy. This determination is generally accomplished by decision making apparatus called Identification-Friend-or-Foe (IFF) systems. Virtually every IFF system has as its fundamental element a Friend-Accept decider, also commonly known as a Reply Evaluator. It is this Friend-Accept decider which determined whether a sufficient number of received correct reply-signals come from a friend or an enemy. An enemy may be attempting to guess the code, or repeat previously intercepted friend replies or attempt to interface with reception of replies transmitted by friends. Hopefully, a Friend-Accept decider will be able to detect these attempts and initiate appropriate action. One type of Friend-Accept decider utilizes a Friend-Accept decision criteria that accepts an approaching vehicle as a friend only when it responds with a series of correct replies to a predetermined number of interrogations.

Descriptors :   *Patents, *IFF systems, *Decision making, Multipurpose, Observation, Threshold effects, Sequential

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE