Arena (countermeasure) - System Details

System Details

The Arena system was primarily designed to defeat threats such as the rocket propelled grenade and the anti-tank missile, including newer anti-tank missiles with longer ranges. The active protection system can protect against missiles fired from both infantry carried rocket launchers and from helicopters, which attack the vehicle directly or by overflying it. Modern rocket propelled grenades can penetrate almost 1 metre (39 in) of steel armour, posing a serious threat to tanks operating in environments of asymmetric warfare. Therefore, increased tank protection requires either an increase in armour thickness and weight, or alternatively the use of an active protection system, like Arena.

The system uses a multi-function Doppler radar, which can be turned on and off by the tank commander. In conjunction with radar input, a digital computer scans an arc around the tank for threats, and evaluates which of the tank's 26 quick-action projectiles it will release to intercept the incoming threat. In selecting the projectile to use for defeating the threat, the ballistic computer employs the information processed by the radar, including information such as flight parameters and velocity. The computer has a reaction time of 0.05 seconds and protects the tank over a 300-degree arc, everywhere but the rear side of the turret. The system engages targets within 50 metres (55 yd) of the vehicle it is defending, and the ammunition detonates at around 1.5 metres (1.6 yd) from the threat. It will engage any threat approaching the tank between the velocities of 70 metres per second (230 ft/s) and 700 metres per second (2,300 ft/s), and can detect false targets, such as outgoing projectiles, birds and small caliber bullets. Arena works during the day and night, and the lack of electromagnetic interference allows the system to be used by multiple vehicles as a team. The 27-volt system requires approximately one kilowatt of power, and weighs around 1,100 kilograms (2,400 lb). Arena increases a tank's probability of surviving a rocket-propelled grenade by between 1.5–2 times.

Shtora was a soft-kill system, designed to passively defeat anti-tank missiles by jamming their guidance systems. By contrast, Arena is a hard-kill system like Drozd, designed to destroy the warhead through the use of munitions before the missile can engage the vehicle being protected.