E801M

The E801M “Oko” (Э-801 «Око») is an L-band (IEEE designation) or D-band (NATO designation) pulse-Doppler radar designed for air and sea surveillance, with an instrumented range of 135 nautical miles (250 km) and a range resolution of less than 500 meters. It supports air-to-surface, air-to-air, or combined operational modes, capable of simultaneously tracking up to 40 airborne or surface threats. Utilized by the Ka-31 helicopter for airborne early warning, patrol, anti-piracy, and search-and-rescue missions, the radar incorporates a 6-meter-long, 1-meter-high, 200 kg phased-array antenna. This antenna, comprising four rows of 24 radiators each, is rotatably mounted under the helicopter’s fuselage, enabling electronic scanning in elevation and providing 6 hits per scan.

radartutorial.eu: https://www.radartutorial.eu/19.kartei/08.airborne2/karte002.en.html