What is the function of the IFF selective ID feature transponder?

The transponder's IFF (Identification Friend or Foe) selective ID feature primarily serves the function of determining whether an aircraft is friendly or hostile. This technology enables military forces to differentiate between their own assets and potential threats in the operational environment. When a radar system sends a query to an aircraft equipped with an IFF transponder, the transponder responds with a coded signal that indicates whether the aircraft is recognized as a friend based on the system's pre-established criteria. This identification process is crucial for ensuring heightened situational awareness, preventing friendly fire incidents, and facilitating safe coordination in complex airspaces.

The other options do not represent the core functionality of the IFF selective ID feature. While enhancing communication, improving navigation, and coordinating air traffic are important aspects of aviation operations, they do not specifically relate to the identification of aircraft as friend or foe, which remains the primary purpose of IFF systems.