Semi-Automatic Ground Environment

The Semi-Automatic Ground Environment (SAGE) was the Cold War operator environment created for the automated air defense (AD) of North American and by extension, the name of the associated network of radars, computer systems, and aircraft command and control equipment ("SAGE Defense System") to replace the United States Air Force "manual air defense system" (Col John Morton). SAGE radar networks were created by the development of each of 24 Direction Centers (DC) in large "cube" buildings and housing IBM AN/FSQ-7 Combat Direction Centrals. Each DC provided radar netting for an Air Defense Region using data from numerous remote Air Force Stations each manned by SAGE radar squadrons operating several radars for searching/detecting, height finding, and for those which guided Bomarc missiles, tracking radars. The DCs also were linked with each other via a "crosstelling" communication network and interfaced with the Army Air Defense Command Posts including 10 Missile Masters for the smaller Nike missile radar networks. Each SAGE DC provided data to a Combat Center for "supervision of the several sectors within the division" and which had an IBM AN/FSQ-8 Combat Control Central that gave "each combat center the capability to coordinate defense for the whole nation" (cf. Cheyenne Mountain--operational in 1966). SAGE included a Canadian DC at CFB North Bay for the Northern NORAD Region (Goose Air Defense Sector) with the SAGE DC operational on October 1, 1963, and which was the only DC with an underground/hardened nuclear bunker

SAGE was operational from December 1, 1958 (Hancock Field NY for the Syracuse Air Defense Sector) and the Joint Surveillance System replaced SAGE in 1983.