64N6E

The 64N6E (Cyrillic: 64Н6Э), known by NATO designators as "Tombstone" and later variants as "Big Bird," is an S-band (2.9–3.3 GHz) phased array radar. Operating as a search and acquisition radar, it is designed to detect both aerial targets and ballistic missiles with an accuracy of 200 meters and 0.5 degrees. Developed for the SA-10A "Grumble" (S-300) surface-to-air missile system starting in 1967 and entering service in 1979, its signal processing capabilities allow it to detect up to 200 targets. The antenna rotates at 6 or 12 revolutions per minute.

radartutorial.eu: https://www.radartutorial.eu/19.kartei/06.missile/karte014.en.html