The official name of the "north finding system (NFS)" is what?

The official name of the "north finding system (NFS)" is known as the Bearing-distance heading indicator (BDHI). This system plays a critical role in air defense operations by providing directional guidance and helping to establish a reference point for navigation.

The BDHI utilizes various inputs to determine the aircraft's heading in relation to true north, which is essential for effective airspace management and ensuring accurate target tracking. Proper understanding of this system is vital for operators as it enhances their situational awareness and decision-making capabilities in air defense scenarios.

In contrast, the other options represent different types of systems or technologies that serve other purposes in navigation or orientation but do not serve as the official name for the north finding system.