The Russian Woodpecker
is of the Duga radar; a Soviet over-the-horizon (OTH) radar system used
as part of the Soviet anti-ballistic missile early-warning network. The
radar was built near the Chernobyl Power Station as it consumed an immense
amount of power to operate. The location of the radar was kept hidden;
referred to only as a 'childrens' camp' on maps.
The Duga systems were
extremely powerful, over 10 MW in some cases, and broadcast in the shortwave
radio bands. They appeared without warning, sounding like a sharp, repetitive
tapping noise at 10 Hz, which led to it being nicknamed by shortwave listeners
as 'The Russian Woodpecker".