'Hen House' ballistic missile warning radar

Operational ballistic missile early warning was provided by 11 large HEN HOUSE detection and tracking radars deployed at six locations on the periphery of the USSR. Most of these radars are located outside the territory of Russia. These radars can distinguish the size of an attack, confirm the warning from the satellite and over-the-horizon radar systems, and provide target-tracking data in support of antiballistic missile (ABM) deployments.