Section three

Picture talking

The picture shows the radar system commonly used in civil aviation in China. It is a combination of both primary radar and second surveillance radar. On the top of the system we see the SSR antenna which looks like a ladder. It works by sending and interrogation signal which will be responded by the transponders on the aircraft. The SSR can accurately measure the aircraft position and altitude with. At the bottom is the PSR which works by passively bouncing a radio signal off the skin of the aircraft. In China, the two radar systems are always installed together to complement each other so that better surveillance can be offered to ensure flight safety. 

Section four

Video