Primary radar vs Secondary radar-Difference between Primary radar and Secondary radar
This page compares Primary radar vs Secondary radar and mentions difference between Primary radar and Secondary radar types. Primary Surveillance Radar (PSR) is called primary radar and Secondary Surveillance Radar (SSR) is called secondary radar.
Figure-1 depicts primary radar principle of operation.
As shown, Primary Surveillance Radar (PSR) transmits electromagnetic signal energy towards
the target i.e. aircraft. The aircraft acts as passive element and reflects the
EM energy back towards the primary radar antenna.
➨Example of primary radar: ATC radar i.e. Air Traffic Control radar
Figure-2 depicts secondary radar principle of operation. As shown, Secondary Surveillance Radar (SSR) transmits EM signal energy towards the target i.e. aircraft. The aircraft acts as active element and answers with the signal back to the secondary radar. Aircraft houses transponder on board. The transponder responds to interrogation by transmitting coded reply signal back. The response contains informations such as altitude, identification code etc.
The secondary radar transmits pulses and receives digital data coming from the
aircraft transponder. These transponders are used to establish flight identity in military applications.
➨Example of secondary radar: IFF Radar i.e. Identification Friend or Foe Radar