Identification, friend or foe (IFF) is a combat identification system designed for command and control. It uses a transponder that listens for an interrogation signal and then sends a response that identifies the broadcaster. IFF systems usually use radar frequencies, but other electromagnetic frequencies, radio or infrared, may be used. [1] .

When the transponder receives an interrogation request, it broadcasts the configured transponder code (or "squawk code"). This is referred to as "Mode 3A" or more commonly, Mode A. A separate type of response called "Ident" can be initiated from the airplane by pressing a button on the transponder control panel.

2025年1月24日 · As mentioned earlier, there are three main modes: Mode A, Mode C, and Mode S. Each mode transmits different types of information to help ATC and other pilots identify and track your aircraft. On the other hand, a transponder “code” is a specific four-digit number that you, as the pilot, will input into your transponder.

2021年2月26日 · Mode 3 (Military) / Mode A (Civilian) This is the 4-digit code we set in the cockpit as assigned by ATC or what we are doing at the time, often called "Mode 3/A" and usually combined with Mode C to provide altitude information. Mode 3 (Military) / Mode C (Civilian) Provides the aircraft's pressure altitude, sometimes called "Mode 3C." Mode 4 ...

2019年6月17日 · Mode 3 has two different submodes. The first one is Mode A, which is is 4 digit, octal code (digits are between 0–7) that provides temporary identity. Mode C is pressure altitude...

2025年1月22日 · Several IFF modes are in use for military and civilian applications. Modes 1, 2, 4 and 5 are military only, with Modes 4 and 5 possessing encryption capabilities and being designated for use by NATO forces. Mode 3 may be used by both military and civilian aircraft, and Modes A, C and S are civilian only.

2019年12月19日 · According to NATO STANAG 4193 (not publicly available, summary from Wikipedia), the "3" in that description refers to the mode in the Identification of Friend or Foe ("IFF") system: Mode 1 – 2-digit octal "mission code" that identifies the aircraft type or mission. Mode 2 – 4-digit octal unit code or tail number

The SSR interrogation format (sometimes called uplink format) in Mark Ⅹ standard is very simple, consisting of two pulses (P1 and P3) of 0.8 µs width which are separated by a certain time - this determines the mode of interrogation. The table shows the time spacing of the different military and civil modes and indicates their use.

2021年3月9日 · Identification Friend-or-Foe (IFF) is a secure aircraft identification system that detects and tells us the difference between the friendly and hostile aircrafts. These systems use electromagnetic and RF devices to communicate with the aircrafts and identifying friendly, foe or neutral forces in airspace.

Military IFF systems use four modes of operation, identified as mode 1 through mode 4. The basic SSR (civilian) mode is mode A, which is essentially identical to the military mode...