Russian S-400 anti-aircraft missiles deployed in Syria.
The S-400 is one of Russia's most modern air defence systems with an extraordinary reach. From the airbase near Latakia the S-400's surface-to-air missiles could strike targets in an arc that takes in much of Israel; the eastern Mediterranean

Manufacturer: Almaz-Antey arms firm; Deployment: Hmeimim airbase near Latakia - entered service in Russia in 2007; Range: 400km (248 miles); Speed: up to 4.8km (3 miles) per second; Max target height: 30km - can track hundreds of targets simultaneously; Types of target: aircraft, cruise missiles, medium-range missiles, drones, other airborne surveillance systems. (Sources: RIA Novosti, Russian 1TV.ru)

- Long-range surveillance radar tracks objects and relays information to command vehicle, which assesses potential targets
- Target is identified and command vehicle orders missile launch
- Launch data is sent to the best placed launch vehicle and it releases surface-to-air missiles
- Engagement radar helps guide missiles towards target
Images from Russian MoD:




















