Animated Atlas: Air Traffic over North America

Air Traffic Control

The tracking of flights is based on a combination of flight plan and radar tracking data that are collected by 20 FAA Air Route Traffic Control Centers (ARTCC; see map below). This data is transmitted in real-time via geostationary satellite link to the Transportation Systems Center (TSC) in Cambridge, Mass. (also called the Volpe Center). A computer system at the TSC merges this data into a single coherent data stream, which is then redistributed by satellite to the Air Traffic Control System Command Center at FAA Headquarters in Herndon, Virginia, near Washington, D.C., as well as to the Traffic Management Units at each of the ARTCCs, and to a handful of companies that make the data available to private subscribers and to the public.

The major purpose of air traffic control is to separate aircraft to avoid collisions. Air traffic control applies to most commercial and many general aviation aircraft that fly under Instrument Flight Rules (IFR).  In contrast to Visual Flight Rules (VFR ) in which pilots keep their distance from other aircraft under "see and be seen" principles, aircraft under IFR are positioned by air traffic controllers.  Radar is used to keep track of the location of the aircraft.