Duga-3 (NATO reporting name Steel Yard) was a Soviet over-the-horizon radar system. It was developed for the Soviet ABM early-warning network. The system operated from 1976 to 1989. Its distinctive and mysterious shortwave radio signal came to be known in the west as the Russian Woodpecker.
The transmitter for the western Duga-3 was located a few kilometers southwest of Chernobyl (south of Minsk, northwest of Kiev). The receiver was located about 50 km northeast of Chernobyl (just west of Chernihiv, south of Gomel).
The Soviets had been working on early warning radar for their anti-ballistic missile systems through the 1960s, but most of these had been line-of-sight systems that were useful for raid analysis and interception only. None of these systems had the capability to provide early warning of a launch, which would give the defenses time to study the attack and plan a response. At the time the Soviet early-warning satellite network was not well developed, and there were questions about their ability to operate in a hostile environment including anti-satellite efforts. An over-the-horizon radar sited in the USSR would not have any of these problems, and work on such a system for this associated role started in the late 1960s. Duga-3 could detect submarines and missile launches in all of Europe and the Eastern coast of United States.
The first experimental system, Duga-1, was built outside Mykolaiv in Ukraine, successfully detecting rocket launches from Baikonur Cosmodrome at 2,500 kilometers. This was followed by the prototype Duga-2, built on the same site, which was able to track launches from the far east and submarines in the Pacific Ocean as the missiles flew towards Novaya Zemlya. Both of these radar systems were aimed east and were fairly low power, but with the concept proven work began on an operational system. The new Duga-3 systems used a transmitter and receiver separated by about 60 km.
- John Pike. "Steel Yard OTH". GlobalSecurity.org. Retrieved 2010-04-08.
- Bukharin, Oleg; et al. (2001). Pavel Podvig, ed. Russian Strategic Nuclear Forces (in English). Cambridge, Massachusetts: MIT Press.