Which major subsystem of the AN/TPS-75 Aircraft Control and Warning System determines the position of all aircraft?

The major subsystem of the AN/TPS-75 Aircraft Control and Warning System that determines the position of all aircraft is the search radar. This subsystem operates by emitting radar waves and listening for their reflections off any airborne objects, allowing it to detect and track the position, altitude, and speed of aircraft within its operational range.

The search radar is essential for air surveillance, as it provides the foundational data needed for air traffic control and situational awareness in a given airspace. By continuously scanning the skies, this subsystem generates a real-time picture of all aircraft in its vicinity, enabling operators to monitor air traffic effectively.

In contrast, other components such as communications primarily facilitate information exchange among personnel and between different systems, while the local control interface group serves as a user interface for operators, and the identification, friend or foe/selective identification feature focuses on distinguishing between friendly and hostile aircraft rather than on their position.