BMEWS

The Ballistic Missile Early Warning System, or BMEWS, had the longest vision of all the ground radars and was meant for locating and tracking ICBMs (intercontinental ballistic missiles) up to 4800 kilometres.  It was also the oldest ICBM warning system.

The three stations of the system were at Clear, Alaska (which also drew on a phased array radar in the Aleutians), Thule, Greenland, and Gylingdales, Moor Yorkshire.  The project began when Thule was created on September 30, 1961.

The system gave fifteen to twenty-five minutes warning time of a missile, sending all information to NORAD automatically.

It relied on two types of radar, detection radar (DR) and tracking radar (TR).  The DR was the radar that first detected missiles using two fans of energy to do this.  The TR then tracked the missile using pulses.

Canada was not involved in this project.