An active protection system (APS) is a system designed to actively prevent certain anti-tank weapons from destroying a vehicle. Countermeasures that either conceal the vehicle from or disrupt the guidance of an incoming

guided missile A missile is an airborne ranged weapon capable of Propulsion, self-propelled flight aided usually by a propellant, jet engine or rocket motor. Historically, 'missile' referred to any projectile that is thrown, shot or propelled towards a targ ...

threat are designated soft-kill active protection measures. Countermeasures that physically strike an incoming threat to damage or destroy it and thereby limit its ability to penetrate armor are designated hard-kill active protection measures.

Soft-kill measures

Soft-kill measures are designed to defeat guided weapons either by concealing the protected vehicle from them (for example, with a

smoke screen A smoke screen is smoke released to mask the movement or location of military units such as infantry, tanks, aircraft, or ships. Smoke screens are commonly deployed either by a canister (such as a grenade) or generated by a vehicle (such as ...

) or by disrupting their guidance with radiation (for example, with a dazzler). Some systems use laser dazzlers to blind the operator or sensors of

semi-automatic command to line of sight Semi-automatic command to line of sight (SACLOS) is a method of missile command guidance. In SACLOS, the operator must continually point a sighting device at the target while the missile is in flight. Electronics in the sighting device and/or the ...

(SACLOS)

anti-tank guided missiles An anti-tank guided missile (ATGM), anti-tank missile, anti-tank guided weapon (ATGW) or anti-armor guided weapon is a guided missile primarily designed to hit and destroy heavily armored military vehicles. ATGMs range in size from shoulder- ...

(ATGMs), such as the JD-3 of the Type 99 tank. Others use powerful infrared emitters to mask the IR tracking flare present on many SACLOS ATGMs, such as the Shtora-1. Soft-kill measures can be divided into on-board countermeasures, such as dazzlers, which are fixed to the platform and expendable countermeasures, such as smoke grenades, which are ejected upon use. Soft-kill measures may be used preemptively, but are more commonly employed in reaction to detected threats.

Hard-kill measures

Hard-kill measures kinetically attack threatening missiles or other munitions, usually at very close range to the protected vehicle. Explosively formed penetrators (EFPs) or high explosive fragmentation countermeasures are typically used. The exact mechanism of many APSs has not been published. The action of these countermeasures may lead to: *disturbance of the stability of a

kinetic energy penetrator A kinetic energy penetrator (KEP), also known as long-rod penetrator (LRP), is a type of ammunition designed to penetrate vehicle armour using a flechette-like, high- sectional density projectile. Like a bullet or kinetic energy weapon, this ty ...

which will decrease its penetration ability as the deflection angle increases. *premature initiation of a

shaped charge A shaped charge, commonly also hollow charge if shaped with a cavity, is an explosive charge shaped to focus the effect of the explosive's energy. Different types of shaped charges are used for various purposes such as cutting and forming metal, ...

(e.g., too great stand-off), but most likely improper initiation, thereby impeding optimum jet development of the metallic lining, usually copper, in the shaped charge. The copper jet provides most of the anti armor capabilities of shaped charge weapons. *destruction of the

airframe The mechanical structure of an aircraft is known as the airframe. This structure is typically considered to include the fuselage, undercarriage, empennage and wings, and excludes the propulsion system. Airframe design is a field of aeros ...

of an inbound

missile A missile is an airborne ranged weapon capable of self-propelled flight aided usually by a propellant, jet engine or rocket motor. Historically, 'missile' referred to any projectile that is thrown, shot or propelled towards a target; this ...

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses Science Biology * Seashell, a hard outer layer of a marine ani ...

There are many examples of hard kill countermeasures. The Russian

Arena An arena is a large enclosed venue, often circular or oval-shaped, designed to showcase theatre, Music, musical performances or Sport, sporting events. It comprises a large open space surrounded on most or all sides by tiered seating for specta ...

system utilizes a

Doppler radar A Doppler radar is a specialized radar that uses the Doppler effect to produce velocity data about objects at a distance. It does this by bouncing a microwave signal off a desired target and analyzing how the object's motion has altered the fre ...

to detect incoming threats and fires munition to eliminate the threat. The Israeli

Trophy A trophy is a tangible, decorative item used to remind of a specific achievement, serving as recognition or evidence of merit. Trophies are most commonly awarded for sports, sporting events, ranging from youth sports to professional level athlet ...

system fires a multiple explosively formed penetrator (MEFP) to destroy the threat. An American system known as Quick Kill detects incoming threats using an

Active Electronically Scanned Array An active electronically scanned array (AESA) is a type of phased array antenna, which is a computer-controlled antenna array in which the beam of radio waves can be electronically steered to point in different directions without moving the a ...

, which assesses the threat, and deploys a smaller rocket countermeasure. Another American system, known as

Iron Curtain The Iron Curtain was the political and physical boundary dividing Europe into two separate areas from the end of World War II in 1945 until the end of the Cold War in 1991. On the east side of the Iron Curtain were countries connected to the So ...

, utilizes two sensors to reduce false alarms and defeat threats inches from their target by firing a kinetic countermeasure designed to minimize collateral damage. The Russian Afganit active protection system of the Armata AFVs features a millimeter-wavelength radar to detect and track incoming

anti-tank Anti-tank warfare refers to the military strategies, tactics, and weapon systems designed to counter and destroy enemy armored vehicles, particularly tanks. It originated during World War I following the first deployment of tanks in 1916, and ...

munitions. It can reportedly intercept armour-piercing fin-stabilized discarding sabot

s in addition to

high-explosive anti-tank High-explosive anti-tank (HEAT) is the effect of a shaped charge explosive that uses the Munroe effect to penetrate heavy armor. The warhead functions by having an explosive charge collapse a metal liner inside the warhead into a high-velocity ...

(HEAT) munitions.

Potential performance problems

Clutter

Mountains and neighboring vehicles reflect

radio wave Radio waves (formerly called Hertzian waves) are a type of electromagnetic radiation with the lowest frequencies and the longest wavelengths in the electromagnetic spectrum, typically with frequencies below 300 gigahertz (GHz) and wavelengths g ...

s, thus creating radar clutter, which adversely affects radar-detection and radar-lock performance.

Top attack munitions

The trajectories of

top attack A top attack weapon is designed to attack armored vehicles from above, to take advantage of the fact that the armour is usually thinnest on the top of an armoured vehicle. The device may be delivered as a smart submunition or a primary munition b ...

ATGMs like the

FGM-148 Javelin The FGM-148 Javelin, or Advanced Anti-Tank Weapon System-Medium (AAWS-M), is an American-made man-portable anti-tank system in service since 1996 and continuously upgraded. It replaced the M47 Dragon anti-tank missile in US service. Its fire-and-f ...

(US) and Trigat (Germany) plunge down onto their targets. Not all active protection systems are designed to fire at the extreme elevations necessary to protect against such munitions. RPGs fired at a steep downward angle from elevated positions can pose a similar threat.

Examples by country of origin

Hard-kill measures

; :* GL5 ; :*

DIAMANT The Diamant rocket (French for "diamond") was the first exclusively French expendable launch system and at the same time the first satellite launcher not built by either the United States or USSR. As such, it has been referred to as being a key ...

; :* AMAP-ADS ; :* Iron Fist :*

; :* Afganit :*

:* Drozd ; / :* LEDS-150 ; :* KAPS ; :*

:* Quick Kill ; :* Zaslin