Wiktionary
n. 1 (''in a civilian aircraft'') a transponder that responds by sending a code identifying itself 2 (''in a military aircraft'') a transponder that responds by sending a similarly coded signal, only when detecting a code indicating the radar is part of the friendly-forces' network
Wikipedia
Identification, friend or foe (IFF) is an identification system designed for command and control. It enables military and national (civilian air traffic control) interrogation systems to identify aircraft, vehicles or forces as friendly and to determine their bearing and range from the interrogator. IFF may be used by both military and civilian aircraft.
IFF was first developed during the Second World War, with the arrival of radar, and early friendly fire incidents.
The term IFF is a misnomer, as IFF can only positively identify friendly targets, not hostile ones. If an IFF interrogation receives no reply or an invalid reply, the object cannot be identified as friendly, but is not positively identified as foe. There are in addition many reasons that friendly aircraft may not properly reply to IFF.
IFF is a tool within the broader military action of Combat Identification (CID), "the process of attaining an accurate characterization of detected objects in the operational environment sufficient to support an engagement decision." The broadest characterization is that of friend, enemy, neutral, or unknown. CID not only can reduce friendly fire incidents, but also contributes to overall tactical decision-making.
Usage examples of "identification friend or foe".
The Identification Friend or Foe was supposed to tell American radars and missiles that he was on their side, but Winters didn't entirely trust computer chips with his life, and so he squinted his eyes to look for smoke trails that weren't going sideways.
The antivehicle batteries functioned automatically, irrespective of the target's Identification Friend or Foe signal.
The antivehicle batteries functioned automatically, irrespective of the targets Identification Friend or Foe signal.
Burke-who was also responsible for the Wolverine assault rifles-and came complete with an Identification Friend or Foe targeting microchip housing a library of enemy ground signatures, even those recently cooked up by the GMU's computers to indicate Invid Scouts and Shock Troopers.
Camp Charon's central routing system simply assigned each shuttle a unique code derived from its Identification Friend or Foe beacon and then automatically interrogated the beacon whenever a shuttle transmitted a message.
Camp Charons central routing system simply assigned each shuttle a unique code derived from its Identification Friend or Foe beacon and then automatically interrogated the beacon whenever a shuttle transmitted a message.