What is the purpose of IFF in radar operations?

• A. Identification Friend or Foe; interrogates transponders to classify contacts as friendly or unknown.
• B. Interrogates enemy radar to jam it.
• C. Measures range to target.
• D. Detects weather phenomena.

Answer: (A)

IFF is a system that identifies whether a radar contact is friendly by sending an interrogation to a target’s transponder and receiving a coded reply. The transponder responds with standardized codes that confirm a friendly identity (and can provide altitude information in some modes). This helps the radar operator quickly distinguish friend from unknown or potentially hostile contacts, reducing the chance of fratricide in busy airspace. It isn’t used for jamming enemy radar, it doesn’t measure range by itself (range comes from the radar’s own timing), and it doesn’t detect weather phenomena. If a target lacks a working transponder or its reply isn’t recognized, it may appear as unknown.