Active protection system
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Active_protection_system".

An active protection system, or APS, protects a tank or other armoured fighting vehicle from incoming fire before it hits the vehicle's armour. There are two general categories: soft kill systems, which use jamming or decoys to confuse a missile's guidance system, and hard kill systems, which attempt to detect and destroy incoming projectiles. In 2008, Time Magazine names the APS #8 in Time's Top 50 Inventions of 2008.¹

Land vehicle APS

Soft-kill systems were (unsuccessfully) deployed by Iraq in the Gulf War. Iraqi tanks were fitted with strobe lights that masqueraded as the guidance beacon on the back of a TOW missile. The multinational force was aware of their use and adjusted the frequency of their guidance systems so they would not be confused^{citation needed}. A soft-kill system currently in service is the Russian Shtora, deployed on Russian and Ukrainian tanks.

Hard-kill systems are activated when a millimetre-wavelength radar or other sensor detects an incoming projectile. In considerably less than a second, they launch a counter-projectile in an attempt to physically damage or destroy the incoming round. Examples include the TROPHY and Iron Fist from Israel, the Quick Kill system from the United States, and the Russian Drozd and Arena.

Aircraft APS

Attempts to use aircraft-mounted flak cannon as such an APS against anti-aircraft missiles proved ineffective^{citation needed}. Anti-aircraft missiles are designed for effectiveness in a near-miss shot, making APS inefficient and unreliable. Among the effective countermeasures for aircraft are ECM, flares or anti-radar chaff.

DARPA is presently developing the High Energy Liquid Laser Area Defense System, which is planned to be capable of knocking out missiles, and may be used to actively defend future combat aircraft.

Naval APS

Warships have been equipped with similar systems (more frequently known as Close-In Weapon Systems, CIWS), which use small- to medium-caliber (12.7-76mm) guns and guided missiles to destroy inbound missiles and cannon shells. Examples include the US Phalanx CIWS, Dutch Goalkeeper, Russian Kashtan, joint USA/German Rolling Airframe Missile, British Sea Wolf, Chinese Type 730 and Turkish Sea Zenith.

External links

• Active Protective Systems: Impregnable Armor or Simply Enhanced Survivability? — An overview of modern tank active protection systems (PDF)
• Active Protective Systems overview - Defense Update
• Soft Kill Active Protective Systems overview - Defense Update0