Surface-Launched AMRAAM (SL-AMRAAM / CLAWS) Medium-Range Air Defence System, USA

The surface-launched Raytheon AMRAAM air defence system uses the AMRAAM fire-and-forget missile, a surveillance radar, a fire distribution centre and AMRAAM launchers.

In April 2001, the US Marine Corps awarded Raytheon a contract for the development of the Complementary Low-Altitude Weapon System (CLAWS).

In February 2004, the US Army Aviation and Missile Command awarded Raytheon a contract to develop SL-AMRAAM. In November 2005, approval was given for five SL-AMRAAM prototypes to be built and tested.

The US Joint System Program Office at Eglin Air Force Base in Florida manages the ground-launched AMRAAM common launcher program for the US Army and US Marine Corps. The AIM-120 AMRAAM missile is in full production at Raytheon's manufacturing facility in Tucson, Arizona.

Boeing delivered the first integrated fire control shelter in May 2006 and the system successfully completed critical design review in July 2006. SL-AMRAAM is expected to enter service in 2008 and to gradually replace the Avenger air defence system in the US Army.

Raytheon is leading the team developing SL-AMRAAM. The Boeing Company is developing the SL-AMRAAM integrated fire control station at its Huntsville, Alabama, facility. The team also includes Kongsberg Defence and Aerospace of Norway.

SL-AMRAAM

The SL-AMRAAM launcher mounts six AMRAAM missiles on a turreted High-Mobility Multipurpose Wheeled Vehicle (HMMWV). The launcher provides 360° coverage. The launcher is pointed towards its assigned sector or area of responsibility and the missile is launched towards the direction of the target. The launch angle can be up to 70° off the direction to the incoming target threat without reduction of intercept and kill probability.

In June 2007, Raytheon announced the development of additional capabilities for SL-AMRAAM: the SL-AMRAAM ER missile, which will have a range of about 40km, and the capacity to launch Raytheon AIM-9X Sidewinder missiles, which have a range of 10km.

The Boeing integrated fire control station provides Battle Management Command, Control, Computers, Communications and Intelligence (BMC4I). The IFCS uses data from air defence sensors including the Sentinel radar and the future Joint Land-Attack Cruise Missile Elevated Netted Sensor (JLENS).

The United States Army uses the Raytheon AN/MPQ-64 Sentinel Enhanced Target Range and Classification (ETRAC) radar to carry out the surveillance and target search, acquisition, identification and tracking functions. The electronically scanned 3D phased array radar uses range gate pulse Doppler operation at X-band.

Sentinel uses a high scan rate at 30rpm. The range is 75km.

JLENS consists of a large aerostat connected via tether to a ground-based processing station with a long-range surveillance radar and a fire control radar. It can operate at altitudes up to 15,000 ft to provide over-the-horizon surveillance for defence against cruise missiles. In November 2005, Raytheon was awarded a US Army contract for System Development and Demonstration (SDD), to be completed by 2011.

CLAWS (HUMRAAM)

The Missile Research, Development and Engineering Centre (MRDEC) of the US Army Aviation and Missile Command (AMCOM) developed the HUMRAAM (Project 559) medium-range mobile air defence system. The US Marine Corps named the system Complementary Low-Altitude Weapon System (CLAWS).

In trials conducted by the US Marine Corps Systems Command during 1997, the system successfully demonstrated intercept ranges of over 15km. In January 2005, CLAWS successfully completed a series of guided missile flight tests with the destruction of a surrogate cruise missile. The system completed operational testing with the USMC in November 2005 and is ready for fielding and Initial Operating Capability (IOC).

In September 2005, Raytheon was awarded a contract for the fifth and sixth CLAWS production systems. In August 2006, the USMC recommended the termination of the CLAWS programme as part of cuts to spending on air defence capabilities.

A CLAWS unit consists of a fire distribution centre with a fleet of up to eight launchers. The launch assembly is installed on an AM General M1097A2 4x4 HMMWV.

The launch vehicle is equipped with a remote terminal unit with voice and data communications. The launch assemblies are locked in travel position while the vehicle is on the move.

When the vehicle reaches a selected launch position, the launch assembly is unlocked from the travel position and raised to an angle of about 30° elevation.

The crew vacate the vehicle and relocate to a firing position up to 50m away and use a remote control unit to make any adjustments to the elevation angle and to initiate the firing sequence.

SURVEILLANCE RADAR

The US Army uses the Raytheon AN/MPQ-64 Sentinel radar to carry out the surveillance and target search, acquisition, identification and tracking functions. The electronically scanned phased array radar uses range gate pulse doppler operation at X-band. Sentinel uses a high scan rate of 30rpm. The range is 75km.

FIRE DISTRIBUTION CENTRE

The fire distribution centre, mounted on a high mobility vehicle such as the AM General 4x4 HMMWV, provides tactical operational control including target detection, identification, threat prioritising, engagement and kill assessment.

NASAMS (NORWEGIAN ADVANCED SAM SYSTEM)

NASAMS was developed by Hughes (now Raytheon) and Norsk Forsvarteknologia (now Kongsberg Defence). The first production contract for NASAMS was placed in 1994 by the Royal Norwegian Air Force and the system entered service in 1995. It is also in service with the Spanish and US Armies.

The NASAMS firing platoon or unit is operated by 22 soldiers and includes a fire direction centre, a Raytheon TPQ-36A three-dimensional radar and three transportable missile launchers.

The NASAMS launcher is unmanned and is mounted on a transportable pallet with four jack type stabilisers. The launcher is carried on a Norsk Scania Vabis P133H truck. An hydraulic crane on the truck is used to position the launcher at a selected launch site.

Data from the fire direction centre is downloaded to the launcher by fibre optic cable, land line or by digital radio. The NASAMS launcher has six ready to fire AMRAAM missiles.

In August 2005, Kongsberg was awarded a contract from the Norwegian Air Force to supply a Link 16 tactical datalink for NASAMS, which allows the system to be fully integrated with NATO network-based defence systems. The upgraded system, NASAMS II, is scheduled to enter service in 2007.

In December 2006, the Dutch Army placed a contract with Kongsberg for six NASAMS II systems. The systems will be used with the EADS TRML-3D mobile surveillance radar. Deliveries are to begin in 2009.

AMRAAM (ADVANCED MEDIUM RANGE AIR-TO-AIR MISSILE)

The AMRAAM, AIM-120, was developed and is best known as an air-launched fire and forget missile deployed on the F-15, F-16, F/A-18, F-22, F-4F, Sea Harrier, Harrier II Plus, Eurofighter, JAS-39 Gripen, JA-37 Viggen and the Tornado.

The high velocity AIM-120 missile is manufactured in two variants. The AIM-120B is field programmable and the AIM-120C is fitted with smaller control surfaces than the A or B variants, has longer range and has very high agility to counter targets making evasive manoeuvres. The missile travels at Mach 4.

The missile is fitted with an ATK WPU-6B booster and sustainer rocket motor which uses RS HTPB solid propellant fuel. The low smoke motor reduces the probability of detection of launch or flight of the missile.

The missile is equipped with a Northrop strap-down inertial reference unit and uses inertial and command / inertial guidance. A data link antenna is located in the tail of the missile to receive mid-course guidance data. A terminal active radar homing seeker operating at X-band is installed in the nose. The 23kg high explosive warhead designed by Chamberlain is fitted with a smart RF proximity fuse.

HAWK-AMRAAM AIR DEFENCE SYSTEM

Raytheon and Kongsberg Defence have jointly developed the HAWK-AMRAAM air defence system, which combines the capabilities of HAWK and AMRAAM missiles within a distributed architecture. The missiles are mounted on universal launchers, and a fire distribution centre controls target detection, identification, threat ordering, engagement, and kill assessment, as well as short-range air defence cueing.

The system can include the Sentinel radar and the HAWK AN/MPQ-61 high power illuminator for target tracking and illumination, although it is possible to hook up any number of radars and missile systems to the fire distribution centre.

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