FPS-50

AN/FPS-50 radars were the detection, as opposed to tracking, components of the Ballistic Missile Early Warning System (BMEWS). The operational units are located at Thule, Greenland, Flyingdales, United Kingdom and Clear, Alaska.

Initial versions, which became operational, in used fixed, 165 feet tall and 400 feet wide., but mechanically scanned antennas in the UHF frequency band, in the 400 MHz range. They have been replaced by solid-state phased array radars. Each system viewed 120 degrees of the horizon.