RAF Trerew was part of the CHAIN HOME group of RADAR stations on the south coast providing crucial radar cover during the Battle of Britain, without them there would have been very little warning of incoming enemy aircraft. The RADAR was technically inferior to the German equivalent, but due to its simplicity it was very quick to construct and provide a comprehensive coverage of Britain. Even though they were simple, they proved to be very functional by providing distance and direction of incoming enemy formations – later stations were also able to provide elevations too; even though this was never a design goal.
The Germans were never certain of the British radar capabilities even though they had been investigated in 1939 as the war broke out, but never being able to ascertain whether the 12m high radio masts were radar, they were ignored until the battle of Britain. However, they also proved very difficult to destroy due to the open steel structure of the towers; this meant that the Luftwaffe ignored the stations for the rest of the war. If they had realised the massive threat they provided, the Germans would have thrown everything they had at them.
It was brought back online at the start of the cold war to provide a CHAIN Home radar capability to supplement the GCI and CEW stations that were coming online as part of the ROTOR 1 project.