What is a key difference between primary radar and secondary radar?

What is a key difference between primary radar and secondary radar?

• A. Primary radar needs a transponder to function
• B. Secondary radar sends signals but receives no feedback
• C. Primary radar transmits signals and waits for a response
• D. Secondary radar operates independently of other signals

Answer: (C)

The key difference between primary radar and secondary radar is that primary radar transmits signals and waits for a response from a target. This involves the emission of radio waves that reflect off objects, such as aircraft, and return to the radar system, allowing it to determine the location, speed, and other attributes of the object based on the time it takes for the signals to return. In contrast, secondary radar systems rely on transponders installed on aircraft. When the secondary radar sends out an interrogation signal, the transponder on the aircraft responds with information, including the aircraft's identity and altitude. This two-way communication enhances the information available to the radar operator. Understanding this fundamental operation helps clarify the broader context of each system's use and functionality in air traffic control and surveillance operations.

The key difference between primary radar and secondary radar is that primary radar transmits signals and waits for a response from a target. This involves the emission of radio waves that reflect off objects, such as aircraft, and return to the radar system, allowing it to determine the location, speed, and other attributes of the object based on the time it takes for the signals to return.

In contrast, secondary radar systems rely on transponders installed on aircraft. When the secondary radar sends out an interrogation signal, the transponder on the aircraft responds with information, including the aircraft's identity and altitude. This two-way communication enhances the information available to the radar operator.

Understanding this fundamental operation helps clarify the broader context of each system's use and functionality in air traffic control and surveillance operations.