What are the operating principles of Secondary Surveillance Radar?

• A. It uses only radio waves from the ground
• B. It relies on transponder responses to interrogations from ground radar
• C. It captures data through visual observation
• D. It functions independently of aircraft technology

Answer: (B)

Secondary Surveillance Radar (SSR) operates on the principle of receiving responses from transponders installed in aircraft. When the ground radar sends an interrogation signal, the transponder on the aircraft responds with a signal containing specific information, such as the aircraft's identity and altitude. This interaction allows SSR to provide much more detailed data than primary radar, which only detects the presence of an object and does not identify it or provide altitude information.

The use of transponders enables SSR to enhance situational awareness, improve air traffic management, and increase the accuracy of tracking aircraft. By actively engaging with aircraft, SSR can receive and process information that is essential for safe navigation and communication in busy airspace.