The S-300 system was first deployed by the Soviet Union in 1979, designed for the air defence of large industrial and administrative facilities, military bases and control of airspace against enemy strike aircraft. The system is fully automated, though manual observation and operation are also possible. Components may be near the central command post, or as distant as 40 km. Each radar provides target designation for the central command post. The command post compares the data received from the targeting radars up to 80 km apart, filtering false targets, a difficult task at such great distances. The central command post features both active and passive target detection modes.