The Nike system was part of the joint American-Canadian North American Air Defense Command (NORAD) and the U.S. Continental Air Defense Command (NORAD). Within NORAD, the Canadian and American air forces were responsible for detecting, identifying (as friend or foe). and destroying or turning back targets. The detection phase began with the identification of intruders through the Distant early warning radar system, commonly known as the DEW Line. The DEW Line, designed to give warning of hostile aircraft approaching from the north, consisted of a net of radar stations near the 69 north parallel that initially extended from northwestern Alaska to northeastern Canada.
The United States and Canada jointly built and operated the DEW Line. The DEW Line became operational on July 3 1,1957, extended to the Aleutian Islands in 1959. and across Greenland in 1961. The U.S. Navy and U.S. Air Force provided sea flanks for the DEW Line with radar-equipped aircraft. operating from the Aleutian Islands to the mid-Pacific and from Newfoundland to the mid-Atlantic. The DEW Line provided up to six hours of advance warning of aircraft penetrating the northern hemisphere, complementary to the Ballistic Missile Early Warning System (BMEWS), which since June 1961 had been on guard to detect approaching ballistic missiles.
The DEW Line also alerted the back-up defenses of NORAD, including the Mid-Canada (55th parallel) and the Pine Tree (49th parallel) radar warning and control lines. The Mid- Canada Line was about 600 miles to the south, built and manned by Canada, and used Doppler detection equipment. The U.S. contiguous radar system was extended offshore by the Navy, as well as by Air Force radar-equipped aircraft. In the Atlantic Ocean, Air Force radar platforms (Texas Towers) were part of a system that was tied together by a communication network terminating in the NORAD command post.
The Semi-Automatic Ground Environment (SAGE), an Air Force command and control system, received all data from these radar networks. SAGE centers were located in several sectors and attempted to identify the intruders and transmit intruder locations to the appropriate Air Force and ARADCOM control and direction centers. Hypothetically, when an enemy intruder entered the band of contiguous radar coverage overlapping the United States- Canadian border, SAGE would initiate attack by sending fighter-interceptor squadrons and launching BOMARC missiles. If the area defense provided by these weapons failed. SAGE continued tracking the intruder and passed this information to ARAACOM Nike fire units. Nike batteries then came into play as "the ultimate defense" of the protected localities.
Once notified of an intruder. ARAACOM would alert the appropriate Army Air Defense Command Post which, in turn, would designate one or more Nike batteries to attack the incoming target. The Nike system utilized a command guidance type of control system that revolved around the use of several types of radars and a computer. The target was initially picked up by the Nike acquisition radars, the LOPAR (low-power radari or HIPAR (high-power radar in the Hercules) systems. From the information provided by the acquisition radar, the target-tracking radar acquired the designated target and tracked it throughout the engagement. The missile-tracking radar locked on the missile prior to firing, and tracked that missile throughout its entire flight.
The two tracking radars fed target and missile position data into a computer located in the battery control trailer. Using this information, the computer continuously determined a predicted point of intercept and issued the steering orders that guided the missile toward that point. At the point of "highest kill probability," the computer issued a burst order to the missile. This order simultaneously detonated the three warheads in the Nike Ajax, and the single warhead in the Nike Hercules. The computer transmitted this order to the missile through the missile-tracking radar.
The battery control officer, stationed in the battery control trailer. received all of the information and controls necessary to engage the enemy target. A series of lights and a meter showed the officer the number of missiles prepared for firing, and the progress of the fire unit in accomplishing the steps necessary to prepare and fire the missile. Prior to firing, the predicted point of intercept and the current position of the target were continuously displayed on two plotting boards in the battery control trailer. With this information, and knowing the rules of engagement and the restricted areas, the battery control officer determined the most advantageous time to fire the missile. After the missile was fired. the two plotting boards illustrated the course of the target and the missile flight path. These plots provided the battery control officer with a graphic presentation of the missile and target flight paths. Controls necessary for premature or delayed detonation of the warheads were incorporated into the system.
The Nike system operated with four batteries in one battalion. Each battery could acquire and track targets, as well as launch and control missiles. Each battery had three underground storage facilities, which had the capability of firing one missile from the elevator/launcher and three others from satellite launchers loaded from the same facility. As sophisticated as the Nike missile was, however, each battery could only track and fire one missile at a time.