Active protection system
Encyclopedia
An active protection system is a system (usually for a military
Military
A military is an organization authorized by its greater society to use lethal force, usually including use of weapons, in defending its country by combating actual or perceived threats. The military may have additional functions of use to its greater society, such as advancing a political agenda e.g...

 application) designed to prevent sensor
Sensor
A sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument. For example, a mercury-in-glass thermometer converts the measured temperature into expansion and contraction of a liquid which can be read on a calibrated...

-based weapon
Weapon
A weapon, arm, or armament is a tool or instrument used with the aim of causing damage or harm to living beings or artificial structures or systems...

s from acquiring and/or destroying a target.

Electronic countermeasures
Electronic countermeasures
An electronic countermeasure is an electrical or electronic device designed to trick or deceive radar, sonar or other detection systems, like infrared or lasers. It may be used both offensively and defensively to deny targeting information to an enemy...

 that alter the electromagnetic, acoustic or other signature(s) of a target thereby altering the tracking and sensing behavior of an incoming threat (e.g., guided missile
Guided Missile
Guided Missile is a London based independent record label set up by Paul Kearney in 1994.Guided Missile has always focused on 'the underground', preferring to put out a steady flow of releases and developing the numerous GM events around London and beyond....

) are designated softkill measures.

Measures that physically counterattack an incoming threat thereby destroying/altering its payload/warhead in such a way that the intended effect on the target is majorly impeded are designated hardkill measures.

Softkill measures

Softkill measures are applied when it is expected that a sensor-based weapon system can be successfully interfered with. The threat sensor can be either an artificial one, e.g., a solid-state
Solid state (electronics)
Solid-state electronics are those circuits or devices built entirely from solid materials and in which the electrons, or other charge carriers, are confined entirely within the solid material...

 infrared detector
Infrared detector
An infrared detector is a photodetector that reacts to infrared radiation. The two main types of detectors are thermal and photonic.The thermal effects of the incident IR radiation can be followed through many temperature dependent phenomena....

, or the human sensory system (eye and/or ear).

Softkill measures generally interfere with the signature of the target to be protected. In the following the term signature refers to the electromagnetic signature of an object in either the ultraviolet
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...

 (wavelength: 0.3-0.4 µm), visual (0.4-0.8 µm), or infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...

 (0.8 - 14 µm) spectral range as well as cm-radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

 range (frequency: 2–18 GHz), mmw-radar (35, 94, 144 GHz) and finally sonar
Sonar
Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...

 range (either 50 Hz - 3 kHz and/or 3– 15 kHz).

One or more of the following actions may be taken to provide softkill:
  • Reduction of signature
  • Augmentation of signature

Softkill countermeasures can be divided into on-board and expendable countermeasures.
Whereas on-board measures are fixed on the platform to be protected, expendable measures are ejected from the platform.

Preemptive action of countermeasures is directed to generally prevent lock-on of a threat sensor to a certain target. It is based on altering the signature of the target by either concealing the platform signature or enhancing the signature of the background, thus minimizing the contrast between the two.

Reactive action of countermeasures is directed toward break-lock of a threat already homing in on a certain target. It is based on the tactics of signature imitation, augmentation, or reduction.

Aerial countermeasures

Generally one has to distinguish between infrared and radar countermeasures. the wavelength range between 0.8 and 5 µm is considered as Infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...

 (IR), The frequency range between 2 and 18 GHz is considered as Radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

.

In the wake of shoulder-launched missile
Shoulder-launched missile weapon
A shoulder-fired missile, shoulder-launched missile or man-portable missile is a projectile fired at a target, small enough to be carried by a single person, and fired while held on one's shoulder...

 attacks against civilian passenger and cargo airliner
Airliner
An airliner is a large fixed-wing aircraft for transporting passengers and cargo. Such aircraft are operated by airlines. Although the definition of an airliner can vary from country to country, an airliner is typically defined as an aircraft intended for carrying multiple passengers in commercial...

s in the early 2000s, various agencies investigated the feasibility of equipping countermeasures such as chaff
Chaff (radar countermeasure)
Chaff, originally called Window by the British, and Düppel by the Second World War era German Luftwaffe , is a radar countermeasure in which aircraft or other targets spread a cloud of small, thin pieces of aluminium, metallized glass fibre or plastic, which either appears as a cluster of secondary...

 and flare
Flare (countermeasure)
A flare is an aerial infrared countermeasure to counter an infrared homing surface-to-air missile or air-to-air missile. Flares are commonly composed of a pyrotechnic composition based on magnesium or another hot-burning metal, with burning temperature equal to or hotter than engine exhaust...

s. Many commercial carriers found the estimated price of countermeasures to be too costly. However, the Israel
Israel
The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...

i airline El-Al, having been the target of the failed 2002 airliner attack, in which shoulder-launched surface-to-air missiles were fired at an airliner
Airliner
An airliner is a large fixed-wing aircraft for transporting passengers and cargo. Such aircraft are operated by airlines. Although the definition of an airliner can vary from country to country, an airliner is typically defined as an aircraft intended for carrying multiple passengers in commercial...

 while taking off, began equipping its fleet with radar-based, automated flare
Flare (pyrotechnic)
A flare, also sometimes called a fusee, is a type of pyrotechnic that produces a brilliant light or intense heat without an explosion. Flares are used for signalling, illumination, or defensive countermeasures in civilian and military applications...

 release countermeasures from June 2004. This caused concerns in some European countries, regarding the possible fire hazard at civilian airports, resulting in banning such aircraft from landing at their airports. In 2007, Saab
Saab
Saab AB is a Swedish aerospace and defence company, founded in 1937. From 1947 to 1990 it was the parent company of automobile manufacturer Saab Automobile, and between 1968 and 1995 the company was in a merger with commercial vehicle manufacturer Scania, known as Saab-Scania.-History:"Svenska...

 announced a new infrared countermeasure system called CAMPS
CAMPS
Civil Aircraft Missile Protection System or CAMPS is an infrared countermeasure against infrared-homed anti-aircraft missiles, specifically designed to defend civilian aircraft flying under against MANPADS....

 that does not use pyrotechnic flares
Flare (countermeasure)
A flare is an aerial infrared countermeasure to counter an infrared homing surface-to-air missile or air-to-air missile. Flares are commonly composed of a pyrotechnic composition based on magnesium or another hot-burning metal, with burning temperature equal to or hotter than engine exhaust...

, thereby directly addressing these concerns.

IR-decoy flares

IR-decoy flares serve to counter infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...

-guided surface-to-air missile
Surface-to-air missile
A surface-to-air missile or ground-to-air missile is a missile designed to be launched from the ground to destroy aircraft or other missiles...

s (SAM) or air-to-air missile
Air-to-air missile
An air-to-air missile is a missile fired from an aircraft for the purpose of destroying another aircraft. AAMs are typically powered by one or more rocket motors, usually solid fuelled but sometimes liquid fuelled...

s (AAM) and can be expelled from a craft according to an anticipated threat in defined sequences.

Radar decoys

To counter radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

-guided missiles, chaff is used. These are copper nickel-coated glass fibers or silver-coated nylon fibers having lengths equal to half of the anticipated radar wavelength.

Naval decoys

Land and sea-based forces can also use such countermeasures, as well as smoke-screen
Smoke-screen
thumb|right|205px|A [[U.S. Army]] [[Humvee]] laying a smoke screenA smoke screen is smoke released to mask the movement or location of military units such as infantry, tanks, aircraft or ships....

s that can disrupt laser
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...

 ranging, infrared detection, laser weapons, and visual observation.

Hardkill measures

Except for countering intercontinental ballistic missile
Intercontinental ballistic missile
An intercontinental ballistic missile is a ballistic missile with a long range typically designed for nuclear weapons delivery...

s, hardkill measures generally refer to measures taken in the so-called "end-game" shortly before a warhead/missile hits its target.
The hardkill measure in general physically affects the incoming warhead/missile by means of either blast and/or fragment action.
The action may lead to:
  • disturbance of the stability of a kinetic energy penetrator
    Kinetic energy penetrator
    A kinetic energy penetrator is a type of ammunition which, like a bullet, does not contain explosives and uses kinetic energy to penetrate the target....

     which will decrease its penetration ability as the deflection angle increases.
  • premature initiation of a shaped charge
    Shaped charge
    A shaped charge is an explosive charge shaped to focus the effect of the explosive's energy. Various types are used to cut and form metal, to initiate nuclear weapons, to penetrate armor, and in the oil and gas industry...

     (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
    Airframe
    The airframe of an aircraft is its mechanical structure. It is typically considered to include fuselage, wings and undercarriage and exclude the propulsion system...

     of an inbound missile
    Missile
    Though a missile may be any thrown or launched object, it colloquially almost always refers to a self-propelled guided weapon system.-Etymology:The word missile comes from the Latin verb mittere, meaning "to send"...

     or shell
    Shell (projectile)
    A shell is a payload-carrying projectile, which, as opposed to shot, contains an explosive or other filling, though modern usage sometimes includes large solid projectiles properly termed shot . Solid shot may contain a pyrotechnic compound if a tracer or spotting charge is used...

    .

Reactive armor

An example of a Hardkill countermeasure is the reactive armor found on many modern armored vehicles.

Antiaircraft weapons

Another example of hardkill countermeasures is the use of short-range missiles or rapid-fire guns to protect warships and fixed installations from cruise missile, bomb and artillery attacks.

Anti-ballistic missiles

Countermeasure
Countermeasure
A countermeasure is a measure or action taken to counter or offset another one. As a general concept it implies precision, and is any technological or tactical solution or system designed to prevent an undesirable outcome in the process...

s are a complicating factor in the development of anti-ballistic missile
Anti-ballistic missile
An anti-ballistic missile is a missile designed to counter ballistic missiles .A ballistic missile is used to deliver nuclear, chemical, biological or conventional warheads in a ballistic flight trajectory. The term "anti-ballistic missile" describes any antimissile system designed to counter...

 defense systems targeting ICBMs. Like aircraft, ICBMs theoretically could evade such systems by deploying decoy
Decoy
A decoy is usually a person, device or event meant as a distraction, to conceal what an individual or a group might be looking for. Decoys have been used for centuries most notably in game hunting, but also in wartime and in the committing or resolving of crimes.-Duck decoy:The term duck decoy may...

s and chaff in the midcourse phase of flight. Novel proposed chaff mechanisms describe the creation of a "threat cloud" by deploying large aluminized PET film
PET film (biaxially oriented)
BoPET is a polyester film made from stretched polyethylene terephthalate and is used for its high tensile strength, chemical and dimensional stability, transparency, reflectivity, gas and aroma barrier properties and electrical insulation.A variety of companies manufacture boPET and other...

 balloons which could conceal a warhead among a large number of inert objects having similar radar profiles.

Explosive Warhead

Once intercepted by the active protection system, a few meters ahead of the Tank,
the shock-wave shaves any piece of equipment off that tank, including the APS itself.

Clutter

Mountains and neighbouring vehicles reflect radar energy, thus creating clutter which adversely affects radar-detection and radar-lock performance.

No Off-Road Protection

Protection needs be provided when a vehicle is driving, especially off-road, rattling and shaking badly continuously.
That includes fast driving plus agile maneuvering. Yet, no comments were made about testing while on the go.
The effect of a moving vehicle to be protected, is exacerbated by the fact that the APS projectile is unguided,
which means that deflections to its initial trajectory, caused by the rattling of the vehicle while driving off road,
cannot be corrected later.

Diving munitions

Diving ATGMs like FGM-148 Javelin
FGM-148 Javelin
The FGM-148 Javelin is a United States-made man-portable third generation anti-tank missile fielded to replace the Dragon antitank missile.-Overview:Javelin is a fire-and-forget missile with lock-on before launch and automatic self-guidance...

 (USA), Trigat
Trigat
The PARS 3 LR in German service, also known as TRIGAT-LR and AC 3G in French, is a currently in development fire-and-forget missile which can be used against air or ground targets...

 (Germany) and Spike
Spike
Spike may refer to:-Device to puncture or fasten:* Nail , especially one over ten inches long* Rail spike, or Screw spike used to construct railroad tracks* Tree spiking, making a tree dangerous to cut with a chainsaw...

 (Israel) attack the tank turret's top,
requiring the APS to attack nearly vertically, which it might have not been designed for.
The same is true for an RPG being fired in a steep downwards angle from a high floor at the road below
or from atop a rocky wall along a mountainous road.

See also

  • Electronic countermeasures
    Electronic countermeasures
    An electronic countermeasure is an electrical or electronic device designed to trick or deceive radar, sonar or other detection systems, like infrared or lasers. It may be used both offensively and defensively to deny targeting information to an enemy...

  • Infrared countermeasures
  • Flare (countermeasure)
    Flare (countermeasure)
    A flare is an aerial infrared countermeasure to counter an infrared homing surface-to-air missile or air-to-air missile. Flares are commonly composed of a pyrotechnic composition based on magnesium or another hot-burning metal, with burning temperature equal to or hotter than engine exhaust...

  • Anti-aircraft
  • Anti-ballistic missile
    Anti-ballistic missile
    An anti-ballistic missile is a missile designed to counter ballistic missiles .A ballistic missile is used to deliver nuclear, chemical, biological or conventional warheads in a ballistic flight trajectory. The term "anti-ballistic missile" describes any antimissile system designed to counter...

  • National Missile Defense
    National Missile Defense
    National missile defense is a generic term for a type of missile defense intended to shield an entire country against incoming missiles, such as intercontinental ballistic missile or other ballistic missiles. Interception might be by anti-ballistic missiles or directed-energy weapons such as lasers...

  • Strategic Defense Initiative
    Strategic Defense Initiative
    The Strategic Defense Initiative was proposed by U.S. President Ronald Reagan on March 23, 1983 to use ground and space-based systems to protect the United States from attack by strategic nuclear ballistic missiles. The initiative focused on strategic defense rather than the prior strategic...

  • Camera countermeasures  LEDS active protection system
    LEDS-150
    LEDS-150 Land Electronic Defence System is an active protection system, developed by Saab Avitronics, a South African subsidiary of the Swedish aerospace and defence company, Saab....

     Drozd active protection system Arena active protection system
    Arena Active Protection System
    The Arena is an active protection system developed at Russia's Kolomna-based Engineering Design Bureau for the purpose of protecting armoured fighting vehicles from destruction by light anti-tank weapons, anti-tank guided missiles , and missiles with top attack warheads. It uses a Doppler radar...

     Iron Fist active protection system
    Iron Fist Active Protection System
    Iron Fist is a hard-kill active protection system designed by Israel Military Industries , with a modular design allowing adaptation to a range of platforms ranging from light utility vehicles to heavy armoured fighting vehicles. The concept was revealed by IMI in 2006 and was expected to enter...

     Quick Kill active protection system Trophy active protection system
    TROPHY Active Protection System
    Trophy is an active protection system , designed to supplement the armor of both light and heavy armored fighting vehicles. It intercepts and destroys incoming missiles and rockets with a shotgun-like blast...

     AMAP-ADS Active Protection System
    AMAP-ADS Active Protection System
    AMAP-ADS is a hard-kill active protection system , developed by the German company ADS Gesellschaft für aktive Schutzsysteme, a daughter company of IBD Deisenroth Engineering, as part of their Advanced Modular Armor Protection protection concept. The system is also known under the name AAC in...

     Zaslon Active Protection System

External links

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