Which system provides primary radar returns and interference data?

The surveillance radar system is designed specifically to detect and track aircraft and other objects within a defined airspace. It provides primary radar returns, which include the raw data necessary to locate and identify targets, such as the position, altitude, and speed of aircraft. Additionally, this system plays a crucial role in gathering interference data, which is vital for ensuring the safety and efficiency of air traffic management by detecting potential threats or anomalies in the airspace.

In contrast, while a weather monitoring system focuses on atmospheric conditions and weather patterns, it does not primarily serve the function of tracking aircraft. The control tower system is a component within the airport environment that manages the movement of aircraft on the runways and taxiways but relies on data from surveillance radar rather than providing primary radar returns itself. The National Airspace System encompasses all elements of air traffic management, including surveillance radar systems, but it is not a specific system that provides radar returns directly. Therefore, the surveillance radar system is the most accurate answer for providing the primary radar returns and interference data.