Ballistic Missile Early Warning System, Site I, Thule

 military, radar station, early warning radar

The BMEWS sensors consist of an AN/FPS-120 two-faced phased array radars located at Thule AB, Greenland, AN/FPS-120 at Clear AFS, AK, and an AN/FPS-126 three faced phased array radar at Royal Air Force (RAF) Fylingdales, United Kingdom.

12th Space manages and operates the AN/FPS-120 model solid state phased array radar or SSPAR for short. The radar became operational June 24, 1987, replacing the old system consisting of the AN/FPS-50 Detection Radar and AN/FPS-92 Tracking Radar, which was in use for more than a quarter of a century.

Thule (Site 1) was the first UHF phased array radar designed for BMEWS ICBM warning. This dual-faced phased array radar contains 3169 antenna elements per face of which 2560 per face transmit and receive RF energy. Each array provides 870 kW of RF power. The arrays receive target returns, which are processed by the signal processors and sent to the prime mission computers for final processing and transmission to forward users.

On October 5, 1960, the moonrise occurred directly in the path of the Thule detection radar, producing a strong signal return. While the computer system never generated an impact prediction, the large amount of data caused enough concern that the equipment was subsequently modified to reject moon returns based on their long (2 second) delay.

Phased Array Radar,used in present day.
upload.wikimedia.org/wikipedia/commons/9/9b/PAVE_PAWS_R...

www.radomes.org/museum/documents/BMEWS.html