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Warfare has changed, so should have methods.

the Israeli offensive against the Gaza strip in late 2008-early 2009 was only the last of a series of conflicts that mostly took place in urban areas. Initiated by air raids, operation 'Cast Lead' ground attack started six days later and penetrated the highly urbanised areas two weeks after the first fighters dropped their precision guided ammunition over the strip, showing how this scenario is still considered very dangerous.

The increased precision of air-launched weapons adds to the equation of urban warfare as it allows to better prepare the ground before an offensive and to support own troops even during the operation. This, however, requires superior intelligence gathering, especially in the preparation phase, in order to hit the maximum number of key targets to facilitate the task for ground troops. Not only does such a task require the use of good sensors, but also the capability to maintain a persistent surveillance over the area in order to check, until the last moment before the attack, that targets are still where they had initially been located, as unnecessary collateral damage would spark strong reaction from the international community.

In current asymmetric conflicts those who normally exploit urban areas to defend themselves do not have air support, therefore the risk for air vehicles over the area is mainly related to small arms fire, medium-calibre weapons and shoulder-launched surface-to-air missiles. In that scenario the use of medium-altitude long-endurance (male) drones can ensure the required air surveillance and monitoring, as well as the targeting (either providing the grids of the single targets or designating them with an encoded laser beam during the attack). Describing the air assets, which can prepare the ground before an operation in urban terrain, providing there is sufficient time to carry out the whole intelligence and destroy missions, goes beyond the scope of this article. However, the need for the attacking party to have the best possible situational awareness means that the intelligence collection process is far from complete when the first bombs or missiles are dropped on the targets. Indeed, the urban warfighter needs a continuous update on the situation ahead of his sector, and to do so other types of unmanned assets that are becoming available at the lower echelons are of vital importance as they reduce risks for the soldiers while providing a better understanding of the situation at all command levels.

Drones

While males can provide overall intelligence cues (not only image but also signal and communications), at tactical level the urban warfighter needs a drone that can be deployed quickly in the sector of interest just ahead of a unit, which can be at company, platoon or even at team level. Pre-planned missions can be carried out in the urban environment, although the quick changes typical of that scenario often require re-planning; this can become quite difficult especially when operating in urban areas characterised by tall buildings that tend to create the so-called "urban canyons" where flying drones becomes critical. One could fly over the roof height but with considerable limitations in terms of visibility.

Fixed-wing mini and micro drones flying at speed are suited for general reconnaissance missions as their typical orbiting pattern used during surveillance and targeting missions is only partially effective in urban areas, many areas being shadowed by multi-storey buildings. This does not mean that such type of drone has not been used in action: Israeli troops used Elbit Systems Skylark mini drones during Cast Lead in order to obtain information at short range while US troops deployed their Aerovironment Raven A and Raven B both in Iraq and Afghanistan-and similar drones are also being employed by many other countries. The Elbit Skylark I has a 2.2-metre wingspan, a 5.5-kg maximum take-off weight and can fly for about two hours at a speed between 20 and 40 kt with a colour CCD camera or a thermal imaging sensor. The Raven A and B have the same airframe, with a 1.4-metre wingspan and a 1.9-kg launch weight, but the later type has a 90-minute endurance versus 60 for the earlier version, an improved day camera with 3x zoom or an infrared camera with laser designator, and a much lighter ground segment.

Numerous other similar systems are available, such as the German EMT Aladin, with a 1.46-metre wingspan, three- kg all-up weight and over 45-minute endurance. Thales is industrialising its Spy 'Arrow, a very-low-cost micro drone with a polystyrene body that was already tested downrange by French Army troops. The service goal is to have a system that can be readied for launch by hand in less than one minute by an infantryman. The Spy 'Arrow would then remain circling awaiting its flight path, which will be planned on a standard laptop already in use by the forces, the waypoints being sent to the air vehicle via a datalink that also provides real-time GPS geo-referenced imaging generated by the visible or infrared stabilised payload. The Spy 'Arrow has a 67-cm wingspan and is powered by an electrical motor with a two-blade pusher propeller. It has an endurance of about 30 minutes and its speed varies between 30 and 100 km/h. Its airframe is made of foam which, together with a weight of only 500 grams (70 grams being the payload), considerably reduces damage in case of accident. The Spy 'Arrow proved its resistance when a prototype carried out 22 flights with only small sticky tape repairs required. The French Direction Generale pour 1' Armement has assigned a study on 'Avionics and Payloads for Micro-UAVs' aims at identifying complementarities between fixed and rotary-wing, taking good points of both systems in terms of payload capacity, endurance, manoeuvring capabilities, etc. Thales is working on anti-collision systems and studying the suitability of flying fixed-wing micro drones in urban areas as well as exploring ways of providing large area surveillance in near-real-time through image mosaic techniques.

While fixed-wing mini drones have been around for a while on the battlefield, vertical-lift systems are still in their infancy, operationally speaking. Systems currently available can be subdivided in micro and mini categories, the former having an all-up weight of around one kilo and a range of one to two kilometres. Among these is the Fancopter developed by EMT in Germany-an electrically powered drone with counter-rotating rotors (one over and one under the motor casing) with a weight of 1.5 kg, a maximum speed in excess of 50 km/h and an overall diameter of 73 cm. A downward-looking wide angle CCD colour video camera provides both surveillance and flight situational awareness for the pilot. The main sensor is mounted on a two-axis tilt head over the motor case and can be of different types: a daylight CCD colour camera with full Pal resolution (752 x 582 pixels) and tele-lens, a low-light full-resolution camera or an infrared video camera with a 320 x 240-pixel resolution. Images can be downloaded in real time to the ground control station at a range of over 500 metres in the worst conditions with beyond direct line-of-sight-operations possible thanks to the high-penetration capability of the radio link. A high-resolution still camera can also be fitted to the Fancopter, but due to the dimensions of its picture files the images would be kept in storage and transferred once the air vehicle is recovered. Depending on the pay-load, the minimum endurance is 25 minutes, which can be increased to over three hours if the Fancopter is used in the perching mode, i.e. landing it on the top of a building for static surveillance.

Another system of that kind is the Airrobot manufactured by the homonymous company in Germany. Based on four rotors powered by brushless motors, a composite structure of one metre diameter protects the dynamic parts. The Airrobot weight is less than than one kilo with 200 grams of payload, it can withstand winds up to eight m/s and is equipped with a datalink in the 1.4 to 2.5 GHz band with a range of 500 metres, while the system endurance is 30 minutes. Among its sensors are a 470-television-line daylight colour video, a 570-line 0.0003 lux low-level camera, a high resolution (ten Mpixels) digital camera and a 384 x 288 infrared thermal imaging camera with a detection range on personnel of up to 100 metres. Also from Germany, the Rheinmetall Defence Electronics Pearl is again based on four rotors but has a much higher weight at 3.3 kg with an 800-gram payload, although its overall dimensions are similar to those of the Airrobot. This drone is not only used for surveillance and monitoring but can drop a 200-gram payload, i.e. a less-than-lethal grenade on a mob. The Pearl's range is about one kilometre and it can be equipped with a down-looking television camera as well as an overhead stabilised IR/TV camera. This air vehicle can reach a speed of 40 km/h and withstand winds up to ten m/s.

Utri of Italy chose a different approach to the problem with its Spyball-a two-kilo drone with a 30-cm diameter electrically driven ducted rotor with a payload capacity of 400 grams, which can fly for over 25 minutes at a height of between five and 35 metres and at an operational speed of about 15 km/h (although maximum dash speed is 40 km/h). The Spyball camera is installed in the side of the body and can be a day/night type, with a x10 optical zoom, or thermal, with a x2 digital zoom. Compared to the previous system the Spyball features the standard datalink used by Utri, which provides a range in excess of twelve km. The Spyball is in the final testing phase and should soon be available on the market.

Upscale, Honeywell developed the T-Hawk (formerly the Micro Air Vehicle, or Mav) aimed at the Future Combat System's requirement. The T-Hawk was developed according to the Class I requirements and has an all-up weight of 7.7 kg (7 kg dry), its ducted rotor being currently powered by a gasoline engine. With a maximum translation speed of over 70 km/h, it can take-off and land with winds of over 15 knots and has an endurance of over 50 minutes. Often referred to as a "hovering lawnmower" it is relatively noisy although with its 60 dBA at 125 metres it becomes practically inaudible in an urban environment. Its 450-gram payload is quickly interchangeable and can include an electro-optical or infrared sensor which provides detection and recognition ranges of man-sized targets at ranges of 250 metres in daylight or 100 metres at night. The on-board datalink provides a range of between five and ten kilometres, depending on surrounding conditions. It was acquired by the US Navy which ordered 180 systems in packages containing two air vehicles, one ground station and spares, and will deploy with bomb disposal teams. Following trials carried out by the 25th Infantry Division the Army decided that it needed a higher payload capacity, allowing to carry day and night cameras at the same time, as well as a target designating system. This led to a revised contract with Honeywell for the development of an up-scaled version with a take-off weight of around 18.5 kg and a ten hp jet fuel engine. One of the major drawbacks of the T-Hawk is its gasoline engine, knowing that carrying gasoline around a battlefield is highly dangerous. This led Honeywell to sign a contract with RCV Engines in Britain for the design and production of a rotating cylinder valve engine operating on standard military grade JP8 fuel.

The above-mentioned Utri of Italy has developed an air vehicle with a similar architecture, but features a twin counter-rotating ducted rotor. Not only does this technique offer better lift, it solves the problem of having to control torque steering. Known as the Asio, it has a six-kilo take-off weight with a one-kg payload, and is powered by electrical brushless motors. Its endurance is about half that of the T-Hawk, which is quite normal as its power supply is provided by Lithium-ion Polymer batteries. This can, however, be extended to four to six hours when the system operates mostly in the perching mode, providing real-time imagery up to ten to 13 km thanks to its data-link. The Asio stabilized payload has a [+ or -]70[degrees] pan coverage and a +70[degrees]/-40[degrees] tilt coverage, and includes either a day/night colour video camera with x10 optical zoom or a thermal camera with a x2 digital zoom. The sensor package can be installed either in the bottom or top position, depending on the mission, and when the main sensor is located in the top position a fixed colour day/night CCD camera is available in the bottom position for precise landings. Fully developed, the Asio is being demonstrated to various potential customers.

Singapore Technologies, Fantail 5000 is another example of vertilift drone that can operate in urban areas. Also based on a ducted rotor it has a diameter of 46 cm and a height of 1.15 metres. Tipping the scales at 6.5 kg it is powered by an electric motor and has an endurance of 30 minutes. It features a unique capability in that it can fly horizontally at high speeds, up to 90 knots. Its range is about eight kilometres, and its payload is located on the top of the airframe.

Currently at the end of its development process-it reached technology readiness level 7-the Goldeneye 50 by Aurora Flight Sciences was initiated under a contract from the US Defense Advanced Research Projects Agency (Darpa) and brings together the benefits of vertical take-off and landing and aero-dynamic sustained flight. Also based on a ducted rotor, it has two short wings spanning 1.35 metres and four rear empennage surfaces. Aurora used the 8.2-kg air vehicle to develop the control technology needed to carry out the continuous transition between the vertical, the hovering and the high-speed flight modes, the Goldeneye 50 being able to hit the 100-kt mark--something that is out of reach for pure vertilift systems. With a one-kilo payload and an endurance of about one hour, the Goldeneye 50 was born as a technology demonstrator and therefore some of its current features will have to be modified in order to transform it into an industrialised product. The drone is currently powered by a two-stroke gasoline engine, however the company plans to soon adopt a heavy fuel engine which will be retrofitted on existing air vehicles in order to avoid the use of gasoline on the battlefield. The fixed camera used for trials will be replaced by a gimballed stabilised camera (payload miniaturisation has made a quantum leap since the beginning of the Aurora drone development). The bigger brother, the Goldeneye 80, is already equipped with such a heavy-fuel engine and a 7-inch gimbal. With a takeoff weight of 82 kg, a 2.9-metre wingspan, a payload of 7.3 kg, an endurance of eight hours (three in hovering mode), the Goldeneye 80 can reach 120 kts and fly at a 15,000 ft altitude. Its acoustic signature is relatively low, the bird being considered 'undetectable at useful stand-off ranges', which means that it can acquire, identify and illuminate a target with its electro-optical, infrared, laser rangefinder and laser designator package, from a range at which the targeted enemy cannot hear it. Its targeting capability together with its hovering capacity make it a valuable asset in urban warfare, when illuminating a target in an urban environment becomes difficult for a fixed-wing system.

Numerous other helicopter-like drones of various dimensions are available on the market, ranging from small ones such as Oto Melara TRP5 Ibis (ten kg) and the Eads Scorpio (13 kg), all the way up to much larger systems such as Saab Skeldar 150 and Skeldar M (respectively 150 and 200 kg), Cybaero (160 kg), Eads Orka-1200 (680 kg) and the Northrop Grumman RQ-8B Fire Scout, which is the largest in the category weighing more than 1.4 tonnes (and many other such systems are being developed throughout the world). While small helicopter drones based on a conventional rotor configuration may suffer bigger damages than ducted rotor types in the event of a collision (a clear danger in urban scenarios), the larger helicopter types can be weaponised and thereby offer a good firing platform. In the intelligence-gathering role their capacity to hover for a relatively long time can also provide some advantages over fixed-wing drones, although static actions over areas which may be infested by opponent forces can present unacceptable risks even for unmanned platforms. As for the possibility for small ducted rotor drones of flying into buildings, this is something much advertised by manufacturers, although it seems rather difficult that such missions can be performed with drones that do not feature reliable anti-collision systems, while a real-time mapping system would also be needed in order to allow operators to properly understand the building layout and the position of the drone within the building.

Ground Robots

Ground robots currently in service are still essentially tele-operated robots, guided by a man via a cable or a radio link. Moving on rough terrain with obstacles is much more difficult than moving in the air, therefore ground robots still require more work from their operators compared to the drones. Although their use is not yet as widespread as that of drones, ground robots are being extensively employed especially by US forces both in Afghanistan and Iraq for reconnaissance purposes, while other armies (French and German among others) use them mostly for explosive disposal purposes. Israel extensively used its robots in the Cast Lead operation last January. According to Israeli soldiers, the use of robots saved lives in numerous occasions. One story reported from a witness tells of a human figure which could be seen on the top floor on a two-storey building; however there was something wrong, and a robot was sent in to check. The camera showed that it was a doll, which, in the intent of the enemy, should have drawn Israeli soldiers into the building. Once the doll was shot down, it was discovered that it was booby-trapped. And this was only one of many examples.

Ground robots will certainly be of use and will help reduce risks, but they will not be the overall solution in urban warfare, due to their inherent limitations mostly in the field of vulnerability, lack of self-protection and their dependency on a datalink-at least until true artificial intelligence systems mature. Moreover, a true reconnaissance robot will have to detect enemy presence on its own, as opponents will certainly not open fire against something that does not represent an immediate threat. Robots certainly help improving situational awareness, however they have to be kept in the right perspective.

Mobility on the rough ground of an urban scenario, which can present major obstacles such as rubble, stairs, etc., is not easy to achieve. This explains why the most widely used systems feature a tracked chassis. Reconnaissance robots are normally small, as they have to be able to move in confined areas. The best example of such vehicles is certainly the Packbot, developed and produced by iRobot of Burlington, Massachusetts. Some 2200 have been sold to date. The tracked chassis has a weight of 22 kg (including two battery packs), is 69 cm long, 50 cm wide and 19 cm high. The system is equipped with two swivelling 'flippers' (which can be removed to reduce the width to 40 cm) which allows the Packbot to move on all types of rough terrain and to climb stairs. The system was designed on a modular chassis that can be equipped with various kits, ranging from reconnaissance to different ordnance disposal systems, to the Red Owl sniper detection system. Most of these kits are parked entirely within the vehicle volume for maximum protection, in order to allow the warfighter to drop the robot even from a certain height, as it can withstand up to 300 G without problems. The first systems deployed were equipped with the Explorer payload, the head of which is fixed on an arm that is raised once the robot is in service. While two colour driving cameras are used for operating the vehicle, intelligence is gained through a zoom colour CCD camera with a x300 zoom placed within the continuously rotating head that also hosts two arrays of LED illuminators, a two-way audio system and a laser pointer. An infrared camera can also be installed on request. This payload allows warfighters to considerably increase their situational awareness in urban terrain, not only outdoors but also inside buildings. The robot's speed allows it to venture into unknown territory, something much more difficult to achieve with air vehicles.

The successor to the original Packbot is the Packbot 510, which is 30% faster, capable of travelling at speeds of up to 9.3 km/h, but is otherwise very similar. A series of kits-explosive ordnance disposal, Fast Tactical (Fastac), Engineer, First Responder, Hazardous Materiel (Hazmat), ICX Fido Explosive Detection, are being proposed, although two of them have a definite interest for the warfighter involved in urban warfare. One example is the Mapping Kit, which provides structure mapping (i.e. creating and analysing blueprints of buildings), allowing personnel to obtain a preview of what to expect inside a building. The system includes a 360[degrees] laser rangefinder to detect obstacles in the safeguarded tele-unit for accurate positioning and a computation payload to support the advanced robot control behaviours. Real-time mapping and the tele-operation mode are software-driven. Currently the Packbot with the Mapping Kit is considered at technology readiness level 5. In order to increase the safety of the units involved in urban operations, sensors to identify the source of enemy fire are being increasingly used.

The second substantial kit is the Redowl (Robot Enhanced Detection Outpost With Lasers) sniper detection kit developed together with the Photonics Center at Boston University, Insight Technology and Biomimetic Systems. The Redowl system features three high-power laser illuminators working in dot, spotlight and floodlight modes, a ten-kilometre laser rangefinder, an acoustic localizer and classifier (with sensors front and aft), a thermal imager, a digital compass with integrated GPS, an infrared and daylight colour camera with a x300 zoom, a thermal imager with a x2 zoom, two wide-angle cameras, one front and one back, a super bright white LED driving light and a communication link. According to the company, field tests results showed that the Packbot-Redowl combination located the source of rounds fired from small arms (9 mm pistols, M-16 and AK-rifles) at a range of more than 100 metres with a success rate of 94%. The last commercial success was scored by iRobot last February when the US Army Program Executive Office for Simulation, Training and Instrumentation filed an $ 80 million contract for 90 Packbot 510 equipped with the Fastac kit.

Teamed with Boeing, iRobot is also involved in the Future Combat Systems programme for which it developed the SUGV 300 (Small Unmanned Ground Vehicle) series of robots. Three models are available: the SUGV 300 for basic reconnaissance, the SUGV 310 for dismounted EOD and the SUGV 320 for infantry and advanced reconnaissance missions, their weight varying from 11.3 to 14.5 kg without payload. Their architecture remains similar to that of the Packbot, including the two flippers. These robots have a maximum speed of ten km/h, can overcome vertical obstacles 30 cm high, climb a stair with a 20-cm rise and 25 cm run steps and has an endurance of about six hours. The Advanced Recon/B kit, the most complete proposed for the '320, includes a chassis wide-angle camera, a colour zoom camera with a x26 optical and a x12 digital zoom, an infrared illuminator, a drive camera, a GPS, a two-way audio channel, a 'neck' that can be raised to 51 cm with four degrees of freedom, a thermal camera and a 1000-metre laser rangefinder.

Foster Miller, a Qinetiq North America company, is the other dominating player in the ground robotics field, its Talons being widely used by US forces in Iraq and Afghanistan, but also sold to the Netherlands. This 57-kg tracked robot, of which over 1500 have been sold to US forces, saw action for the first time in Bosnia-Herzegovina with explosive ordnance disposal teams and also at Ground Zero. It can carry a 90-kg payload, reach 6.5 km/h or creep at very low speeds, depending on the mission. In an urban scenario it can be used as a reconnaissance asset, although an armed version was developed, as we shall see later. Able to climb stairs, negotiate rock piles and overcome concertina wire, it is a very flexible platform. However, a smaller robot was needed to operate where the Talon could not go. Thus Automatika (which became a Qinetiq North America subsidiary in 2007), developed the Dragon Runner, which in its basic version weighs 6.5 kg and is 31 cm long, 42 cm wide and 15 cm high. The requirement from the US Marine Corps was to have a flexible system to be used in various situations, hence the Dragon Runner's modular design which can be equipped either with wheels or tracks: if speed is needed and the terrain is relatively even, one can pop up the wheels and drive the robot at over 30 km/h. On the other hand, if the mission involves climbing stairs a special set of stair tracks with flippers is available, although ordinary tracks as well as curb tracks are included in kit. A PTZ Servo Cam as well as a Small Unit Sensor System allow to use the Dragon Runner for reconnaissance while manipulator arms and grippers are also available.

Another interesting robot is that developed by Elbit Systems of Israel. Known as the Viper (Versatile Intelligent Known as the Viper (Versatile Intelligent Portable Elbit Robot), it has a unique feature as it is both a wheeled and a rubber-tracked system. The so-called 'Galileo Wheel', developed by Galileo Mobility Instruments of Israel, allows for the benefits of wheels, tracks and intermediate mode for climbing obstacles. When travelling over ground the Viper can configure itself in the wheel mode, retracting the track system within the wheels and thereby improve efficiency, manoeuvrability and increase transfer speed. On rough terrain the internal roller wheels are extended to transform the wheel into a tracked system to provide greater mobility. The Galileo Wheel is also well suited for climbing stairs, as in the wheel mode it can overcome an obstacle that is 85% of its diameter, while in the tracked mode this figure is increased to 200%-compared to 50% for a normal wheel. The Viper weighs less than eleven kilos, is 46 cm long, 48 wide, 23 high and can travel up to 20 km with an endurance of between two and eight hours depending on the nature of the job on hand. It is equipped with three low-light or infrared cameras (one looking forward, one backward and the third elevated), infrared and visible lights and an omni-directional microphone; optional payloads include pan & tilt head, ordnance disposal equipment, etc.

The Israel Defense Force also field the Eyedrive, a 4 x 4 wheeled mini robot developed by ODF Optronics. With a weight of only 2.7 kg in its basic configuration, equipped with four cameras providing 360[degrees] coverage, it can carry up to three kilos of sensors or explosives and can be easily carried due to its limited dimensions, i.e. 280 x 250 x110 mm. The Eyedrive system is actually made up of two robots that can be thrown over a wall or through a window to operate simultaneously and a communication unit that is linked to a laptop--the whole package weighing less than ten kg. Equipped with microphones and with infrared or visible illumination systems, it can broadcast images and sounds to a range of up to 300 metres in the open and 70 metres inside buildings, using a 900-MHz datalink. The Eyedrive has a 'point-and-go' navigation system: the operator points the robot's destination on the touch screen.

The Eyedrive is not the only system used by the IDF, the Eyeball is also part of the game. The Eyeball is a robotised system that can be thrown or rolled for over 50 metres without damaging the sensors to provide continuous video and audio coverage for up to 2.5 hours, with broadcasting distances about half of those of the Eyedrive. It is equipped with a self-stabilisation system and has a diameter of 85 mm for a weight of 580 grams. Its motor allows it to roll at four revolutions per minute. The video sensor can be a colour or black & white with a 470 TVL resolution, a video feed of 25 frames/sec and a 55[degrees] field of view. The microphone can catch a human voice at five metres while a near-infrared source allows to illuminate at a range of eight metres. The Eyeball is also in service with the US Army, which acquired at least 300 systems from Remington Technologies, representing ODF in the United States, and which also supplied the Eyeball to numerous law enforcement agencies.

In 2006 at Eurosatory, Thales exhibited its ground robotic system called the R-Trooper, a 6 x 6 device with an overall weight of over 500 kg and a maximum speed of over 50 km/h, powered by a hybrid system. Its diesel engine provides up to an eight-hour endurance, while its motor offers a 20-minute run with a charging time of two hours. A technology demonstrator, it is not aimed at becoming a product as such since Thales believes that in urban warfare medium-sized robots currently lack any form of autoprotection. Since 2007 the company has been working on increasing the autonomous capability by developing modes that can function without datalink, the final aim being to obtain a robot that relates to its surroundings in a 'human way' (probably putting in parallel various algorithms) and thus conduct a mission under full autonomy. A kit for transforming standard vehicles into robotic vehicles is also under development. This could be used in urban warfare to open routes, check for roadside explosives, detect sniper fire, etc. Downrange, Thales developed the [mu]-Trooper, two of which could be transported by the R-Trooper, but apparently the company considers this market already saturated by US products.

Many other companies are active in the ground robotics field, one of them being Oto Melara teamed with Celin Avio, whose TRP-2 tracked robot was shown at the recent delivery ceremony of the Freccia armoured infantry vehicle, armed with a Minimi machine gun. In a well-oiled scenario, the robot exited the Freccia via the rear ramp carrying out close-range reconnaissance to demonstrate a possible role within the Forza-Nec net-centric programme. Other robots were shown by the company at Eurosatory, the smaller being the 5.5-kg TRP-3, a wheeled recce vehicle with a one-kilo payload.

All the robots described were mostly devoted to reconnaissance and to EOD/IEDD missions. Other missions for mid-size robots can be envisaged in the resupply area to avoid exposing personnel on urban roads. Armed ground robots have not yet been deployed (at least officially) although many countries, the United States in particular, are developing and testing such systems. Firing a lethal weapon from a robot, even with a man-in-the-loop as far as the shooting sequence is concerned, has to be thoroughly analysed, particularly in the light of its impact on public opinion. Indeed, while such systems would allow to considerably reduce risks in urban areas, it is far easier to identify an enemy tank at long range in the open ground than to tell an enemy, especially if not uniformed, from a civilian in the heat of an urban combat situation during an asymmetric confrontation. So far the United States is known to have tested the Swords (Special Weapons Observation Remote Direct-Action System) in Iraq in June 2007 with the 3rd Infantry Division. Armed with an M249 light machine gun, not much is known about the use of this Foster-Miller Talon derivative apart from issues over its reliability. As a result, the army has requested a number of upgrades. This led to the Maars (Modular Advanced Armed Robotic System) in which Foster-Miller introduced a new modular design; armed with the more powerful M240B machine gun it features significant improvements over the Swords in terms of command and control, situational awareness, manoeuvrability, mobility, lethality and safety. Based on the XM1219 Multi-functional Utility/Logistics and Equipment Mule, the US Army is developing the ARV-Assault-Light (ARV-A-L) with an integrated weapons and reconnaissance, surveillance, and target acquisition package to support the dismounted infantry's efforts to locate and destroy enemy platforms and positions. When, how and how many armed robots will be deployed in the early future remains a matter for speculation.

Unattended Ground Sensors

After describing unmanned mobile systems that can provide a considerable contribution to urban operations, another category of systems that can increase situational awareness is that of static unattended ground sensors (UGS). This category of systems has recently been the subject of a dedicated article (Armada International 2/2009 pages 8 to 12) however some systems have purposely been developed for urban scenarios.

Textron together with Honeywell developed the Urban-Unattended Ground Sensors (U-UGS) aimed at the US Future Combat Systems programme, although such a system can be integrated in any other net-centric system. Based on wireless sensors, the U-UGS can be used in typical urban missions such as clearing classical choke points like stairwells and corridors, as well as monitoring other areas such as caves, tunnels and sewers. *It will give us more hands and more shooters in urban environments, *as a US Army NCO put it. Few technical data were released, as the system is still in development phase. What is known is that an AN/GSR-10 (V) 1 kit, the Army name for the U-UGS, will be made of two gateway nodes, five imaging sensors and ten intrusion detection sensors. The gateway nodes act as bridges between the sensors in the field and the FCS command network, communicating sensor data to FCS C2 Joint Tactical Radio System (JTRS) systems and to the local dismounts. It thus relays alarms and images to the upper echelon while also providing a human interface to the clearing team on the ground. The Intrusion Sensor Node is a dual-mode sensor (passive infrared and microwave motion sensing), which can detect a moving person within a 15-metre range. Discriminating between a human being and an animal, it alerts the operator in less than two seconds, while the Imaging Sensor Node extends the capability of the previous sensor by incorporating an imaging capability that allows positive identification of the intruder. The imaging sensor is equipped with electro-optical visual imaging, plus a near-infrared illuminator for operation in full darkness. Each sensor represents a node which allows the system to create its own network once positioned, the maximum distance between nodes within buildings or in complex terrain being 100 metres, well in excess of what would be normally needed. The U-UGS components can be positioned by hand or can also be deployed using a small robot. The US Army plans to equip each Brigade Combat Team with 29 U-UGS kits. The U-UGS is probably the only unattended sensor system purposely developed for urban operations, although many of the 'field scenario' systems hitherto developed can be used in an urban context, especially in the road choking point monitoring role. However, many of them would find their limits inside buildings.

Incoming Shot Detection

Urban terrain is sniper land. Sarajevo's 'sniper alley' will forever remain in the memory of those who saw television reports during the Bosnia-Herzegovina crisis. Gunshots are fired at relatively short range, not to say very short range, and sound reflection effects can affect a soldier's ability to properly identify the source of the incoming fire. Therefore automatic gunshot detection systems are becoming increasingly popular among troops, static, vehicle-mounted or worn by the soldiers themselves. BBN Technologies developed, under Darpa sponsorship, the Boomerang acoustic gunshot detection system which is now in its Boomerang III iteration.

Deployed in Iraq and Afghanistan, where it has already proven its value in different situations, the system is made of two elements, the mast/array which is 2.1 metres tall and carries a 50-cm-diameter array of microphones, and the manmachine interface in the form of an 18 x 12 x 8-cm box with a display, a loudspeaker and a watch-dial type display. The overall weight of the Boomerang III is eight kg, its power consumption is 25 Watts, and it can be installed in less than one hour on a Humvee. The system can operate at a vehicle speed of more than 100 km/h detecting over 95% of supersonic incoming bullets passing within 30 meters in less than 1.5 seconds. "Shot, one o'clock," is the type of oral warning the Boomerang gives to the soldier, while the clock-dial type display system indicates direction. The screen on the other hand provides bearing data with an error of less than 2.5[degrees], range with an error of [+ or -] ten per cent, and elevation with an error lower than 2.5 [degrees]. BBN Technologies worked hard on reducing as much as possible the false alarm rate due to non-ballistic events on the vehicle such as wind noise, doors slams, road bumps, as well as noises coming from outside such as vehicle traffic, urban activity and others. The system remains passive when shots are fired from within the vehicle.

Quite often forward operating bases are established in urban areas. The British Army 3 Para, for instance, was forced to set up numerous forward operating bases in Afghan towns along the Helmand Valley, which proved to be a highly dangerous undertaking. Warning systems are not the final answer, but they can increase the accuracy of friendly fire to neutralise a threat. In this role Boomerang III sensors can be networked to provide overall coverage of the base and can be interfaced with remote stations, such as the Trap-T2 from Precision Remotes, as well as with electro-optical sensors (Radiance Technologies' Weapon Watch, for example).

In order to improve single soldier safety BBN Technologies started to develop a wearable version known as the Boomerang Warrior. The system is based on a dual composite rigid shoulder pad sensor array with embedded processing which provide full 360[degrees] coverage in any orientation, standing or prone. Built-in soldier motion correction allows the user to obtain an accurate shooter range estimation and updated hostile shooter location depending on to the soldier's own displacement. The audio warning message is provided by an earpiece while a lightweight wrist display provides the visual cueing. A lightweight power pack completes the system.

A similar system is the Ears miniature sniper detection system developed by Qinetiq North America. It weighs only 340 grams and provides the direction and range of the firing source in less than half a second alerting the soldier with a vocal message, giving range and direction. The microphones are located in a small box worn on the shoulder while a manmachine interface that includes a watch dial-type display that provides the visual cues. The Ears can detect shot at over one kilometre over 360[degrees] even when moving in a vehicle at 80 km/h (a specific interface allowing its vehicular use is required). In late November 2008 the US Army placed an order worth $ 9.95 million for the Swats (Soldier-Wearable Acoustic Targeting Systems), a version of the Ears system, which was being delivered to Iraq and Afghanistan in early 2009.

01dB-Metravib of France developed an acoustic gunshot detection system following French Army experience in Sarajevo along 'Sniper Alley'. The system, known as Pilar, has now evolved in the Pilar Mk IIw, which is more user-friendly and able to 'hear' incoming RPGs. It is available in two versions, one for area protection, and the other for vehicles. The former is based on two foldable acoustic sensor arrays, weighing two kg each, with embedded sensors and electronics, a Data Interface Acquisition Module (Diam) which processes the signal of the arrays in real time and a rugged laptop to control the system and visualise the results using Shotguard software. By detecting the passing bullet shockwave and the weapon muzzle blast, the Pilar algorithms work out bearing, elevation and range of the firing weapon as well as the bullet trajectory. Locating precision is within [+ or -]2[degrees] in bearing and a [+ or -]20% in range depending on the distance between the two arrays, while the detection range can exceed 1500 metres. It detects calibres from 5.56 to 20 mm with a response time of fewer than 1.5 seconds. The static version can be used for protecting forward bases in urban locations, which are often attacked by insurgents. The vehicle-mounted version uses a single sensor array identical to that of the ground based type (but with a specific mounting) and allows identification of the gunshot's origin with the vehicle on the move at a maximum speed of 45 km/h. Bearing precision when in motion is of [+ or -]5[degrees], the range accuracy of [+ or -]50 metres for short to medium distances and [+ or -]100 metres for long distances. The company is constantly upgrading the software and the latest versions see all the computing devices included in the Diam; this allows the extraction of data without the need of a laptop and to feed them straight into a vehicle battle management system that automatically orients the turret onto the source of fire and keep it under observation with the vehicle Optronics.

For lighter vehicles without BMS 01dB-Metravib has developed the Navkit, a GPS navigation module that computes and memorises the firing source position in grid terms. Other software updates discriminate between small and medium-calibre rounds. The Pilar Mk IIw has also been tested on helicopters and fast riverine craft. A soldier-wearable version is under development, the company planning to show pre-production items at Eurosatory in 2010. Both versions of the Pilar Mk IIw are in service with some 20 countries. Users are the American Special Forces Command units, Australia, numerous Nato Forces (France, Germany and Britain), as well as unknown customers in the Middle East and Asia; Belgium and Poland adopted the vehicular system, the former on their Piranhas, the latter on their Humvees and Rosomaks.

Rafael from Israel also offers an acoustic detection and direction-finding system in two versions, man-portable or vehicular. When worn by a single soldier the Sads (Sniper Acoustic Detection System) has a helmet-mounted microphone and a compass-clinometer, while vehicles use a microphone array. The Sads detects and identifies a firing signal up to ranges of 1000 meters with standard deviation of less than 3[degrees] and elevation accuracy of five.

Electronic Warfare

In a conventional combat situation, electronic warfare would essentially be aimed at a uniformed enemy. In the situations that prevail in Afghanistan or in Iraq, the insurgents' electronic communications are mostly based on mobile phones and the Internet. Amongst electronic warfare options signals intelligence (sigint) remains one of the principal information gathering means; while intercepting conversations might prove difficult (particularly because of the small amount of linguists that are able to translate what has been intercepted), monitoring phone traffic can provide interesting cues for intelligence analysts, allowing them to disseminate warnings to operational forces. An increase in communications in certain areas can signal a prelude to an action while communication silence can mean that the action is ongoing, breaking out in a peak of phone calls should a firefight break out.

The American forces have deployed a plethora of sigint assets in Afghanistan, mostly to monitor and try to apprehend those who manufacture and position roadside bombs. Other countries have fewer assets but they tend to monitor the approaches to their areas of operation in order to assess the threat level. The French contingent deploys the Saec (Systeme d' Appui Electronique de Combat). Mounted on a VAB equipped with a mast that can be raised up to 18 metres, it improves the system's performance. Other undisclosed nations employ such systems on different chasses. The TRC-6200 monitors the spectrum and detects and locates emissions. In four to five years' time Thales intends to introduce electronic warfare capacities in its vehicle-based software-defined radios, in order to provide detection and classification of enemy communications for alert purposes. Israeli companies such as Net-line are also very active in the sigint field against mobile phones.

Communications

Radio-frequency propagation in urban situations is affected by the presence of buildings, often made of concrete, which generate all sort of disturbances to radio waves. Many line-of-sight radios developed for conventional warfare have thus proven inadequate for urban operations. Multi-pathing is a common occurrence when operating radios inside a walled environment: this leads radio signals to split or bounce off multiple surfaces causing weaker signals and/or a poor signal quality at the receiving end. Moreover some frequencies tend to have problems penetrating concrete, steel and brick structures.

Satcoms are of scarce use, as in urban canyons it is very often impossible to track a satellite, a problem that also affects blue force tracking systems based on GPS receivers linked to radios, since the GPS signal is often shadowed by tall buildings. The choice of frequency, as well as that of the output power are of key importance: normally to mitigate multipathing and maintaining a good penetration the frequency falls in the UHF band, around the 400 MHz, while two Watts of output power ensure sufficient range to punch through artificial barriers typical of the urban scenario. Radios capable of ad-hoc networking also improve the signal quality as each of them acts as a relay when other sets within the net are not able to communicate directly.

The Harris RF-7800S is one of the answers to the problem; operating in the 350 to 450 MHz frequency range, it has a power output of two Watts adjustable to one or 250 mW, and in urban environment its range is around 800 metres, more than sufficient to cover team/platoon operations. This radio, which weighs 300 grams and is equipped with an embedded GPS for blue tracking purposes, has been selected by the Norwegian Army as the soldier radio for their Normans future soldier programme. It is also being evaluated by several other standardization programmes around the world.

The Raytheon Microlight 1 weighs 480 grams, operates in the 420 to 450 MHz range and has a power output from 100 mW to five Watts. Ad hoc, self-healing networking ensures highest reliability and availability, while its throughput up to one Mbps supports transmission of compressed imagery.

ITT is proposing its Wearable Soldier Radio Terminal (WSRT) as the next-generation communication capability for the dismounted soldier. The terminal links soldiers to each other, bridges the mounted-to-dismounted gap and supports critical reachback communications. The WSRT is a software-defined radio supporting both narrow and wideband waveforms and provides dynamic ad hoc network. It provides soldiers with voice, data, and video capabilities. Working in the UHF band, its transmitting power reaches five Watts, its range in urban conditions is given as one kilometre and weight as 550 grams.

The Thales St@armille hand-held squad/platoon level radio is a lightweight device operating in the 325 to 470 MHz band which ensures a 300-metre range in urban areas (over 1.7 km in open ground). It can simultaneously transmit voice and data and provides a one Mbps throughput for video exchange. The set is voice-controlled, thus leaving hands free for combat, and can operate in crypto mode. Thales should also soon launch its SRT (Software Radio Terminal), a hand-held version of its Flexnet software-defined radio that is currently available in vehicular configuration with a single channel or four channels. Its UHF waveform has mobile high data rate and ad hoc network capabilities and is able to self-manage 150 fully mobile nodes.

Tadiran's Personal Network Radio, the PNR-500, was designed to support data communication to RPDAs, live video transmission to combat computers, embedded or external GPS, advanced encryption for secure communications and bluetooth wireless headsets and PTTs for ultimate combat freedom. It operates in the 410 the 450 MHz frequency range and weighs less than 360 grams including a rechargeable battery that enables continuous operation for twelve hours. The PNR has a whisper function for covert operations, voice activated messages and alerts as well as automatic free frequency search functionality. The PNR-500 can provide an interface for the PNR network to the vehicle's HF and VHF transceivers, through to an effective range of up to 800 meters.

Another category of radios that can tackle the urban warfare comms problem is the multi-band type, more expensive than those previously described, but also more flexible and capable. Among these is the widely used Thales AN/PRC-148 Multiband Inter/Intra Team Radio (Mbitr), now also available in the Jem (JTRS Enhanced Mbitr). Operating in the 30 to 512 MHz frequency range with selectable RF output power from 0.1 to five Watts, this radio is able to 'talk' to aircraft and helicopters using the Have Quick I/II modes, and directly to Sincgars sets. It has a 16-Kbps voice and data throughput and can also be used in Satcom mode.

The Raytheon Microlight DH-500 is another choice as it operates in three bands covering the 225 MHz to 2 GHz frequency range and is capable of mobile ad-hoc networking. It is equipped with embedded GPS and has an output power from 100 mW to 4 Watts. Weighing 760 grams, it has been selected for the Land Warrior programme by the US Army as well as by Thales UK as the core communications system for the British Fist (Future Infantry Soldier Technology).

The ITT Soldier Radio is another example, as it operates in two UHF bands, 225-450 MHz and 450 to 970 MHz, in VHF (30 to 88 MHz) and in the L-Band (1650 to 1850 MHz), with programmable output power from 1 mW to 5 Watts. With a weight of about one kilo, the ITT Soldier Radio is fully programmable, is designed to host JTRS waveforms and features a programmable cryptographic subsystem. Range is given as over one kilometre in urban terrain.

Direct Fire Support

Urban warfare is mostly an infantry business; clearing buildings, 'mopping-up' streets, guarding roofs require basic soldier skills. However, while armoured vehicles and support weapons can provide covering fire, they can also be used to open breaches in walls in order to provide infantry with alternative access to buildings and thereby avoid booby-trapped doors. The rush on 120-mm smoothbore tank guns in the late 1970s and early 1980s when the main battle tank's role was that of tank killer has left the armies with APFSDS rounds that are indeed very good for drilling holes into armour, but not effective at all against masonry and concrete walls. This brought ammunition manufacturers to develop 120-mm multi-purpose rounds.

Alliant Techsystems (ATK) developed the M830A1 Heat-MP-T, commonly known as the 'Mpat', which has been the round of choice in operation Iraqi Freedom. This round features a discarding sabot with sub-calibre warhead and a multi-function fusing system. It also has an airburst capability that is quickly selectable by the gunner. Compared to the previous M830 Heat round it demonstrated a 20% performance increase against bunkers. A modified version of the Mpat, in which the front fuse is replaced with a steel nose, the M908 HEOR-T (High Explosive Obstacle Reduction) has been developed to destroy obstacles and barriers. Its performance is considered to be higher than those of the M123A1 High-Explosive Plastic 165-mm demolition round. Nammo of Sweden and Nexter (then Giat) of France developed the HE-T Mk II round, which was designed to increase the efficiency of main battle tanks in urban and semi-urban scenarios.

More recently, however, and with urban warfare in mind, Rheinmetall designed the DM11 120 K HE-Frag-T 120-mm programmable high-explosive round. Its warhead contains steel and heavy metal fragments, enabling it to achieve excellent results against an extremely wide variety of targets. The full-calibre warhead is equipped with a time fuse featuring a percussion function that can be set with or without delay. Delay value is automatically set by the tank's fire control system. The US Marine Corps has placed an order for trials quantity as part of an effort to meet an urgent need for enhanced urban warfare rounds for its M1A1 Abrams tanks. The DM11 has also been adopted by the German Army, while the Netherlands acquired it with a super-quick fuse.

The company also developed a series of ammunition based on the Penetrator with Enhanced Lateral Effect (Pele) technology, which transforms old rounds into new ammo optimised for urban warfare. This technology can be applied to both kinetic-energy penetrators (drilling them and filling it with inert materiel) and shaped charge Heat rounds. As it penetrates the target the Pele splits apart, generating a large behind-target fragmentation effect. A DM33A1 KE round penetrated concrete walls in excess of 200 mm thickness and a brick wall of over 450 mm. DM-12 Heat 120 mm ammunition modified with the Pele technology proved to be able to open a 160-mm aperture in a concrete wall with only three rounds, half of those needed with M393A2 ammunition according to some sources. Denmark already ordered 120-mm Pele transformed from old DM33A2 APFSDS-T kinetic energy rounds.

Soldiers involved in crisis response operations often find themselves fighting in urban areas; the rules of engagement prevent them from using the same lethal force that they would in a conventional warfare scenario, in spite of very similar threats. In the case of direct fire against buildings the aim is to reduce collateral damage as much as possible. During some testing carried out by Dutch TNO at the Rheinmetall Unterluss firing range and witnessed by the author, a series of rounds were tested against mock Afghan walls, in order to check out breach dimension as well as the collateral damage to neighbouring rooms. Preliminary results showed that the M831A1 and DM18A5, both training rounds, had optimal breaching effect and caused low collateral damage, while the DM33 Pele round showed low collateral damages but limited breach capability due to its original under-calibre round nature.

What is true of 120 mm is not necessarily of 105 mm, as in the past numerous types of rounds were developed for the M68 and L7 rifled guns. Some were indeed particularly apt to open breaches and deal with urban warfare situations, such as the Hesh (High Explosive Squash Head). This was designed to spread the explosive on the target surface before igniting it, thence opening a wide breach. For breach opening the US Army selected the M393A3 round developed by Mecar of Belgium, L-3 Communications being the prime contractor in the United States, this Hep/Hesh type ammunition, loaded with Composition A3 explosive, is designed for defeating reinforced concrete structures, bunkers, light armoured vehicles and personnel targets.

The Israeli military are probably among those with the greatest experience in urban warfare. To address the problems of tank, anti-personnel and urban warfare rounds Israel Military Industries developed the Apam round, an acronym standing for Anti-Personnel Anti-Materiel. Originally born as a 105-mm calibre, the Apam contains six lethal submunitions. A time fuse with a charge ejects them at short intervals from the case, then each sub-munition explodes scattering lethal fragments allowing to hit not only personnel in the open along a 20-metre-wide and 50-metre deep strip, but also infantrymen hiding alongside the road, which led to the Apam's 'street cleaner' nickname. In the time-fuse mode it can also be used against helicopters. Apam rounds can be used in the impact mode against light armoured vehicles as well as against bunkers, the IMI ammunition being capable of creating a hole in a 50-cm thick double-reinforced concrete wall. A 120-mm version has also been developed. Apam rounds cannot discriminate targets in those situations where military and civilian personnel are intermixed. Therefore, based on IDF experience and requirements--IMI has developed the Stun Tank Cartridge which produces only deterrent flash, smoke and sound, allowing tank crews to defend themselves even when aggressors hide within a crowd.

Armoured infantry combat vehicles normally sport 25 to 30 mm cannon to fire ammunition that is seldom optimised for urban warfare. For its new Puma the German Army has chosen the Rheinmetall 30 mm ABM (Air Burst Munition) which works on the Ahead principle, namely releasing a swarm of cylindrical pellets after a pre-programmed time of flight. The extent to which this type of ammunition will be used to neutralise occupants within a building by shooting through breaches or windows (while causing minimal collateral damage in neighbouring rooms) will have to be seen once the Puma is deployed downrange.

Small Arms

The increasing involvement of troops in urban warfare brought the services to look for more compact individual assault weapons, the more visible change being the shift from the M-16 to the M-4 in the American forces. However, 5.56 x 45-mm rounds have long been criticised for being underpowered, and since the mission in Somalia in the early 1990s it was possible to see soldiers of different nations, especially within special forces, reverting to older 7.62 x 51-calibre weapons. These rounds had their own limitations as they were heavy and bulky, thus reducing their numbers in a clip and as a consequence a soldier's firepower reserve. This situation still prevails, although a new calibre packing sufficient energy with a limited weight might come to resolve the quadrature of the circle.

This 6.8 x 43-mm SPC (Special Purpose Cartridge) developed by Remington with the assistance of some US Special Forces elements provides the best combination of combat accuracy, reliability and terminal performance for up to 500-metre engagements. It has a much higher energy, better barrier penetration and incapacitation effect than current 5.56 mm rounds. Most new weapons currently under development are taking into consideration this new calibre and manufacturers plan to develop 6.8 Remington SPC versions of their rifles. Other 6.8 rounds, such as the Kramer Defense Urban Combat Cartridge, which uses a standard 5.56 x 45-mm Nato cartridge case, have emerged, however the 6.8-mm SPC is definitely the one which might replace the 5.56-mm--a magazine of similar dimensions to the Stanag 4179 type containing 25 rounds instead of 30. Currently only Barrett Firearms is marketing a 6.8-mm SPC rifle, the REC7, which features an AR configuration, weighs 3.5 kg and has a 406-mm barrel. How many services will be willing to move to a new calibre better suited for urban warfare in a period of shrinking budgets is matter for conjecture; certainly a limited amount of weapons in the new calibre will soon appear on the battlefield, mostly in the hands of special forces units.

Shoot Around the Corner

Fighting in an urban scenario means that soldiers have to look around the corner before moving on, a gesture which can be quite dangerous if the enemy is just waiting for that on the other side. A number of 'look-and-shoot-around-the-corner' items have thus emerged in the recent past. Most of them were based on folding stocks with a vision system mounted on a handgun, but not many such items made it to the battlefield. However, with the current emergence of 'modern soldier' programmes around the world, such systems are bound to spread very rapidly. These are mostly made of an optronic aiming sight installed over the weapon that forwards the image to a monocular worn by the soldier, either through a cable or a wireless link. The French Felin sight is cable-linked to the OVD monocular, the Italian Aspis sight sends its images via a Bluetooth 1.2, the German IdZ Videovisier also works via a wireless personal area network, the Spanish Comfut sight feeds images to the Liteye LE 750A helmet-mounted display via a wireless system, and so on. All these systems have night and day channels.

Weight, however, is an issue. These systems add between 1 and 1.5 kg to the rifle, which make the weapon system quite heavy and bulky, something not really optimal in urban areas were the threat can materialise anywhere at very short ranges. Increasing the weapon system weight means increasing the time needed to train the weapon toward the opponent--a very simple physics rule called inertia. This is the main reason why soldiers from the US 4th Battalion, 9th Infantry Regiment, which deployed with the Land Warrior equipment in Iraq in 2007, immediately dropped their optronic sighting system replacing it with a holographic sight, most of the engagements being at close range due to the urban type scenario in which they were normally operating.

Another type of sight that can be handy in close quarter battle is the RSA-S (Reflex-sight Small Arms). This reflex sight is ideal for fast reaction and for use in close quarters, enabling fast target acquisition and reliable targeting. Its red dot adapts automatically to ambient light conditions, but can also be adjusted manually. Weighing only 110 grams, it features a hybrid power supply made of a solar silicium cell and a battery, which switches automatically to battery operation if the light is not sufficient to power the sight with solar energy, ensuring a long endurance. Elcan Optical Technologies, a Raytheon company, developed the SpecterDR, which can be switched from x1 to x4 magnification and vice versa in less than one second. In the close quarter battle mode at x1 the rifleman can keep both eyes open, while in long-range firing he shifts in x4 mode with ballistic drop reticule.

In the red dot field Aimpoint of Sweden is the dominating company, its CompM2 being the CQB sight adopted by many Special Forces unit, and as M68/CCO (Close Combat Optics) is the standard sight of the US Army and US Air Force. From this sight many improved sights were developed such as the CompM3, which advanced circuit efficiency technology increases by a factor of five the battery endurance. While the two systems mentioned are compatible with all night vision devices, the CompML2 and ML3 are designed for daylight and low-light conditions. Recently Aimpoint developed the CEU (Concealed Engagement Unit), which placed behind a CompM sight allows around-the-corner viewing.

Armouring the Armour

The urban arena is certainly not the optimum playground for armoured vehicles. A few years ago upgrade programmes to turn tanks and armoured carriers into urban warfare assets were all the rage. Apart from a few armoured vehicles specifically modified for this urban role, such as IMI's Urban Fighter, an M113 APC equipped with passive add-on armour protection against roadside bombs, RPG (Slat) and 14.5-mm AP, sporting a cupola fitted with ballistic side-windows to provide optimal situational awareness and front and side ballistic windows for the driver, other vehicles have been upgraded to a lesser extent.

Abrams tanks are receiving the Tusk (Tank Urban Survivability Kit), which includes armour upgrades to the rear and bottom of the hull, slat armour to protect the engine compartments and reactive armour to improve flank protection against RPGs. M-1A2 are being equipped with a Crows remote controlled weapon station armed with a .50 machine gun that can be operated with closed hatches.

Most European armies are studying the problem, but few have adopted enhancements to their vehicles deployed downrange. Most kits would include add-on armour, optronic systems for a better 360[degree] situational awareness and remotely controlled turrets with a high elevation angle (at least 70[degree]) in order to provide suppressive fire against targets hiding in buildings. Active protection systems require to be effective at very close ranges, thus with very short reaction times, and systems such as IBD Deisenroth Amap ADS are still in the last development stages. Certain developments are exemplified by the Rheinmetall Fuchs exhibited at Eurosatory in 2008. The vehicle was equipped with enhanced roadside bomb and mine protection, Autoflug safety seats, Aamap ADS, a dozer blade, a 260[degree] electro-optical situational awareness, a Nanuk remotely operated turret, an SKWA 360 rotary grenade launcher which launches lethal and less-than-lethal grenades even at short range, the Rosy rapid obscuring system while a C4I system allowed the vehicle to be part of the net-centric environment.

Other solutions are proposed by many other companies, although nothing will really be able to transform the urban environment into a haven for any vehicle.
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Title Annotation:Urban Warfare 2009
Author:Alpo, Paul V.
Publication:Armada International
Article Type:Company overview
Date:Aug 1, 2009
Words:10759
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