Close-in weapon system

A close-in weapon system (CIWS), often pronounced "sea-whiz", is a point-defense weapon system for detecting and destroying short-range incoming missiles and enemy aircraft which have penetrated the outer defenses, typically mounted shipboard in a naval capacity. Nearly all classes of modern warships are equipped with some kind of CIWS device.

There are two types of CIWS systems. A gun-based CIWS usually consists of a combination of radars, computers, and multiple-barrel, rotary rapid-fire cannons placed on a rotating gun mount. Missile systems use infra-red, passive radar/ESM or semi-active radar terminal guidance to guide missiles to the targeted enemy aircraft or other threats. In some cases, CIWS are used on land to protect military bases. In this case, the CIWS can also protect the base from shell and rocket fire.

A gun-based CIWS usually consists of a combination of radars, computers and rotary or revolver cannon placed on a rotating, automatically-aimed gun mount. Examples of gun-based CIWS products in operation are:

CIWS are also used in a land-based anti-mortar and missile defense role to protect fixed and temporary bases and other facilities.

On a smaller scale, active protection systems are used in some tanks, and several are in development. The Drozd system was deployed on Soviet Naval Infantry tanks in the early 1980s, but later replaced by explosive reactive armour. Other systems that are available or under development are the Russian (Arena), Israeli (Trophy), American (Quick Kill) and the South African-Swedish (LEDS-150).

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