Communication channels for SAGE data systems

The sage (semiautomatic ground environment) system is a system of air surveillance and control designed to aid in the air defense of the continental United States. In this system of air surveillance, flight information is transmitted from radars and other sources to a central point where it is processed and evaluated to form a comprehensive picture of the air situation. This picture covers the search area of several radars, thus providing centralized surveillance of a sizable geographic area. The provision of this surveillance capability requires the evaluation of a large amount of information. In addition, to be of any practical use, the surveillance picture must not lag the actual air situation by any very appreciable interval of time. To accomplish this, the flight information must be gathered and evaluated very rapidly. This has been accomplished by minimizing the use of human beings in the surveillance system and leaning heavily on automatic methods. The various automatic data units in the SAGE System are, however, geographically scattered and must be interconnected so that they can process and exchange the flight information. This interconnection is made by special communication systems called data transmission systems which will be described herein.