For armoured vehicle protection, kill the killer!
Today's active vehicle self-protection systems depend on sensors that are either radar, laser or infrared based and connected to countermeasure systems that can either launch a projectile to directly engage the hostile rocket-propelled grenades, missile and shell or deliver smoke to obscure the intended target from the weapon's seeker head. Other systems dispense with the countermeasure, instead using an airbag to envelope the projectile. While exhaustive tests have shown the real potential of many of these systems to successfully engage incoming munitions, they can impose a weight and size penalty on the armoured and light vehicles they equip. This takes the issue of such installations back into the enduring debate surrounding armoured vehicle survivability, namely the trade-off between armour and speed as the best protection.
In Europe, Germany's Diehl BGT Defence has developed its Awiss active self-protection system. Designed to intercept projectiles at up to 75 metres from the launching vehicle with a three-kilo grenade, the Awiss uses aradar to detect the munition before initiating counter-measures launch, a process which takes 0.355 seconds. The radar sensor provides 360[degrees] coverage. The countermeasure is launched from a directional system that can be slewed towards the threat at a speed of 600[degrees] per second. A system mounted on a Krauss-Maffei Wegmann Leopard 2 tank successfully destroyed an MBDA Milan anti-tank missile during a test on 21 July 2007. However, while there are few doubts about the capability of the system, it does impose a 400-kg weight penalty on the vehicle, and raises the vehicle's height 400 mm and extends a similar length below.
Krauss-Maffei Wegmann is working with Eads on the Muss (Multifunction Self-protection System). Development funding for the Muss was forthcoming from Germany's BWB Federal Defence Procurement Agency in 1997, with Eads tapped to provide the systems' electronic counter-measures, sensors and central computer and KMW acting as the systems integrator for the programme. The Muss is activated by a missile and laser warning system that is closely based on the Eads AN/AAR-60 Missile Launch Detection System sensor suite which outfits the Eurocopter EC-665 Tigre attack helicopter. The sensor determines whether the vehicle is being targeted by a laser designator or by an incoming missile. The nature of the threat is conveyed to the computer which then initiates the countermeasure, activating either a jamming signal directed at the missile, or launching a pyrotechnic smoke device to mask the vehicle. The system's response time is around 1.5 seconds, it can engage up to four targets simultaneously and provides 360[degrees] coverage. The total weight of the Muss is reportedly up to 160 kg, which gives it a fairly flexible collection of large armoured vehicles upon which the system could be installed, such as the Artec Boxer, the KMW Fennek armoured reconnaissance vehicle or the Leopard 2.
Rheinmetall developed the Rapid Obscuring System (Rosy) for lightweight vehicles. At the heart of the Rosy system are 40-mm grenades that can be launched up to 32 metres from the vehicle to create a smoke screen measuring 90 square metres. Vehicles can be equipped with up to four launchers which each carry three smoke canister magazines. The smoke screen can be initiated in around 0.53 seconds; it obscures the vehicle visually and can mask it from television, electro-optical and infrared-guided weapons. The system can also launch grenades equipped with either 'flash bang' or Chlorobenzalmalononitrite (better known as 'CS') gas to disperse individuals standing near the vehicle.
In co-operation with the Italian Ministry of Defence, Oto Melara has developed the Scudo system. This uses a similar radar-countermeasures-based system to that used by the Awiss and Muss. An X-band radar monitors the locale around a vehicle and is connected to up to four countermeasures launchers. Upon detecting incoming ordnance, the Scudo ('shield' in Italian) launches two rockets that use a proximity fuse to spray the forward path of the hostile munition with a storm of tungsten balls. The Scudo also provides close-range defence which uses tungsten balls embedded in tiles placed over the skin of the vehicle with the radar initiating the detonation of these tiles towards the projectile.
Given the serious threat that Israeli vehicles have faced from rockets and anti-vehicle weapons during recent operations in the Gaza Strip and Lebanon, it is unsurprising that several Israeli companies have devised innovative systems. One is the 'Trophy' family of systems, which is also known as Aspro (Armoured Shield Protection). The Israeli Ministry of Defense is funding the development of the Trophy, which is being pursued by Elta with Rafael as prime contractor. The Trophy was introduced on 8 March 2005 in Tel Aviv. However, the product is thought to have been in development since 1995.
The Trophy is built around a quartet of Elta flat panel radars that can be placed on a vehicle to provide 360[degrees] coverage. The radar watches for incoming munitions and then calculates the best point of interception. An interceptor is then launched in the direction of the threat and showers fragments to ensure its destruction. The Trophy has an effective range of between ten and 30 metres from the vehicle, it can be automatically loaded, which reduces the crew's workload, and can engage multiple targets.
The United States Army has shown interest in the Trophy, which succeeded in destroying two rocket grenades during a demonstration in 2006. However, a controversial decision abandoned plans for the US Army to purchase the Trophy for vehicles that would be operating in Iraq. Officially, the Army believed that Trophy was not at a sufficient level of technological maturity and instead has chosen the Raytheon Quick Kill (see below) for this purpose instead.
This being said, Rafael did score success with the Trophy being chosen by the US Marine Corps. The Trophy has also been selected to equip the Israeli Army's Merkava-IV tank. In October 2008 it was reported that an initial 100 Trophy units would be purchased for installation on these vehicles.
It was also revealed in 2008 that the Trophy would be available in a number of versions including the Aspro-A--the type ordered for the Merkava--and the Aspro-A-L system which weighs less and is designed for infantry fighting vehicles and personnel carriers such as the M113, of which Israel has around 6000. The weight saving and size reduction for the Aspro-A-L is achieved with a smaller launcher and countermeasures, connected to the same flat panel radar system used on the Aspro-A. Both systems, however, still impose a significant weight penalty of up to 800 kg for the standard Aspro-A and 500 kg for the Aspro-A-L variant. However. Rafael has worked to reduce the weight of the system further and, to this end, unveiled the Aspro-U-L Ultra Light version, which has been shown on a Rafael Wolf multi-purpose armoured vehicle. One of the principle differences of the Aspro-U-L, compared to the other systems is that the counter-measure launcher has to be manually reloaded.
Also using Elta radar technology is the IMI Iron Fist. The radar is accompanied by an Elbit Elisra Tandir infrared sensor to measure the flight characteristics of incoming projectiles and compute the optimum engagement co-ordinates. Incoming ordnance is defeated with a fin-stabilised canister that hits and destroys the munition without detonating its warhead, this to prevent harm to nearby troops and civilians. The Iron Fist has a multiple target engagement capability.
IMI has tested the system on an M113 and the detection-to-destruction time for the system is around one second. The Iron Fist is primarily intended for lightweight vehicles. Moreover, other roles for the system such as protecting marine craft and fixed installations are mooted for the Iron Fist. The 2008 Eurosatory exhibition in Paris saw an IMI Wildcat armoured vehicle equipped with the system on display.
A bilateral initiative involving Saab Avit-ronics and Denel in South Africa has yielded the modular Land Electronic Defence System (Leds). The baseline product is the Leds-50 system, which warns a crew whether their vehicle is being targeted by a laser designator or rangefinder. This system has been acquired by the Landmacht (Royal Netherlands Army) for use on its CV9035s.The next product in the series is the Leds-100 soft-kill system, which was unveiled in 2004. The Leds-100 takes the Leds-50 sensor and connects it to a pair of high-speed directional launchers. These six-tube systems can then launch smoke grenades to screen the vehicle from the laser threat. The screen can be generated up to 50 metres from the vehicle in under one second. The Royal Jordanian Army has shown interest in equipping its Chrysler M60 tanks with the Leds-100.
The Leds-150, for its part, can destroy incoming weapons at a range of 20 metres. It uses the Denel Dynamics Mongoose-1 interceptor munition, while the Leds-200 is intended to defeat top-attack munitions with foam that is formed to alter a vehicle's visual signature to confuse the munition's seeker. The foam has the added benefit in that it can also be used as a fire suppressant to defeat petrol bombs. A final member of the family, the Leds-300, is planned. This would use the Mongoose-1 munition to intercept stand-off weapons and armour-piercing darts at ranges of up to 150 metres. Some reports have suggested that the Leds-300 could be installed on the South African Army Hoefyster.
Turning to the Future Combat System programme, of which Boeing is the lead systems integrator with its partner Science Applications International Corporation, a system is also being contemplated. In 2006 Raytheon's Quick Kill was selected as the hard-kill system. Test results have been encouraging, in February 2006 the Quick Kill having shown that it could destroy a rocket grenade at a range of 50 metres. At the heart of this development is the Raytheon Network Centric Systems Multi-Function Radio Frequency system, which provides 360[degrees] coverage around a vehicle and tracks incoming munitions. It computes the trajectory of the projectile and sends this information to the Quick Kill system. The Quick Kill has a 16-round launcher, which vertically despatches a single missile which then detonates a downward-facing warhead to destroy the munition while reducing the danger of injury to people in the vicinity of the engagement. The first Quick Kill systems should be ready around 2011.
The Defense Advanced Research Projects Agency is funding Iron Curtain, which is a roof-mounted system intended to equip smaller vehicles like the AM General Humvee. Using optical sensors and radar, the Iron Curtain launches a countermeasure downwards towards the incoming projectile at close range to the vehicle. Also designed for Humvee-sized vehicles is Textron's Traps which uses airbag technology. The radar detects an incoming projectile which then triggers a roof-mounted airbag, which fires downwards. The airbag envelops the incoming munition and arrests its forward momentum. It is then defused by a countermeasure, although Textron declines to name the specific countermeasure used in this portion of the engagement. This entire process from detection to neutralisation takes around 30 milliseconds. One of the big attractions of the Traps system is that it uses off-the-shelf equipment such as a standard police speed detection radar to flag the incoming munition and commercially available airbag technology to reduce the system's cost.
The other attractions of the Traps include 0its low weight penalty of 56 kg for a four-door vehicle and an airbag reloading time of around three minutes. Funding for the Traps programme was forthcoming in 2005 when Textron received a $ 3.5 million contract from the Office of the Secretary of Defense with the project being administered by the US Army Tank Automotive Research, Development and Engineering Center. The 2007 Defense Appropriations Bill saw the Traps initiative receiving a further $ three million of funding. Tests in 2007 showed that the Traps could be effective against RPG-7 rounds. Larger versions of the system are planned which could be used to equip Stryker-sized vehicles.
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||Vehicle: self-protection|
|Date:||Jun 1, 2009|
|Previous Article:||Silencing the bomb path.|
|Next Article:||Boeing paints a new picture.|