How are airport surveillance systems primarily used?

Airport surveillance systems are primarily utilized to monitor and guide aircraft movements within controlled airspace. They play a critical role in enhancing aviation safety and efficiency by providing real-time tracking of aircraft positions and movements. This allows air traffic controllers to manage takeoffs, landings, and taxiing on the runways and taxiways, thereby preventing collisions and ensuring smooth operations in busy airspace.

The systems employ various technologies, such as radar, transponders, and satellite-based navigation, to gather data on an aircraft's location, speed, and heading. This information is crucial for maintaining situational awareness among air traffic control and for providing timely instructions to pilots, thereby facilitating safe and efficient traffic flow in the airspace surrounding the airport.

In contrast, the other options focus on aspects not directly related to the primary function of airport surveillance systems, which centers on aircraft movement monitoring and guidance.