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AGM-88 HARM |
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Medium-range, anti-radar, air-to-surface missile. Development The AGM-88 High-speed Anti-Radar Missile (HARM) is a second-generation development following on from the AGM-45 Shrike and AGM-78 Standard programmes. Studies started in 1972 and in 1974 Texas Instruments (now Raytheon Defense Systems) was awarded the integration contract to support the development work at the US Naval Weapons Centre (NWC), China Lake. The main improvements incorporated in HARM were a broadband antenna, programmable software and the ability to handle higher I-Band (8 to 10 GHz) radar frequencies. AGM-88A entered operational service in 1983, and over the next few years there were several improvement programmes. In the late 1980s the AGM-88B was introduced with a major operational advantage over the AGM-88A in that it had the ability for rapid change of software on the flight line to cope with new threats. Whereas, to reprogramme the original AGM-88A, the seeker was returned to depot for replacement of plug-in modules. This new capability was found to be especially valuable for Operation Desert Storm because some of Iraq's radars and missiles had been acquired from western European suppliers. In 1990 the AGM-88C entered early production with a lower-cost radar seeker with the ability to counter frequency-agile radar targets and an improved warhead. The new warhead was designed to double the lethality and make HARM more effective against hardened structures that house radar electronics. The HARM design has been progressively improved over the years. The AGM-88A had block 1 and 2 versions, AGM-88B was block 3, and AGM-88C was block 4. A block 5 version (AGM-88C) included software improvements and increased frequency coverage. HARM has been cleared for carriage on A-6 Intruder, A-7 Corsair, EA-6B Prowler, F-4G Phantom, F-16 Fighting Falcon, F/A-18 Hornet, F-117 and Tornado IDS/ECR aircraft. The Royal Australian Air Force completed initial flight test of HARM on F-111C in 1988. HARM is also being integrated on the F-15C/D/E aircraft as a follow-on to the Suppressing Enemy Air Defences (SEAD) Wild Weasel role as the F-4G Phantoms are phased out of service. In 1994 it was reported that a contract had been awarded to demonstrate and validate a new targeting device PDF (Precision Direction-Finding) for use with the AGM-88 and to improve the F-15's `Wild Weasel' defence suppression capability. The F-15 PDF will be used to detect, locate, identify and target threat radars using interferometer antennas and a receiver processor. A similar HARM Targeting System (HTS) upgrade for Block 50 F-16s is also planned. Both systems will provide passive ranging and the USAF is also planning to supply data from surveillance aircraft and spacecraft direct to F-15 and F-16 cockpits via datalink. In July 1994 a successful proof-of-concept demonstration of the HTS was carried out at the China Lake Naval Air Weapon Centre, California. During these tests target data was transmitted via satellite to a US Navy EA-6B electronic warfare aircraft where it was correlated with onboard sensor data to identify and locate the radar emitter. The data was then transmitted to the F-16 launch aircraft by an improved datalink. This information was then used to programme the HARM missile for a range-known launch at a target beyond visual range. In 1996 tests were made from an F/A-18 Hornet with a passive precision radar direction-finding system, called the Targeting Avionics System (TAS). The TAS uses two five element antenna arrays fitted to the front section of the outer wing pylons. The arrays provide target radar azimuth and elevation angles to a 1° accuracy. Reports in May 1996 indicated that US Navy proposals for an AGM-88D block 6 upgrade, to fit GPS, have been discussed with Germany and Italy, and that EMD will start in 1998, with a proposed in-service date of 2004. Description The AGM-88 HARM is a medium-range, anti-radar, air-to-surface missile powered by a solid propellant motor and armed with an HE fragmentation warhead. It is cylindrical in shape with a pointed nose and has four moving clipped-tip double delta-wings at mid-body, and four fixed clipped delta tail fins. The missile's body is composed of four major sections: guidance, warhead, control and propulsion. The guidance section contains a fixed-broadband radio frequency antenna, a passive anti-radar homing seeker and a software-adaptable solid-state digital processor to process threat signals. The warhead is a blast/fragmentation type, optimised for radar targets. The control section contains a digital autopilot, a strapdown inertial navigation system and the electromechanical actuators for the wings which are attached to the unit in a cruciform configuration. The propulsion section consists of a solid-propellant, boost-sustainer, low-smoke rocket motor and has four in-line stabilising fins attached to the boat tail. HARM is 4.17 m long, has a body diameter of 254 mm, a wing span of 1.13 m and a launch weight of 361 kg. It is fitted with a 66 kg HE blast/fragmentation warhead that is initiated by an active laser proximity fuze, which determines the detonation of the warhead depending on the final trajectory characteristics. The AGM-88C's improved warhead uses tungsten-alloy fragmentation cubes in place of the lighter steel cubes in the original warhead. HARM operates by locking onto hostile radar emissions either before or after launch. The radar may be initially detected by the launch aircraft's onboard radar warning receiver or the missile's own seeker operating in the search mode. AN/ASQ-213 HARM Targeting System (HTS) pods are fitted to the starboard side of the fuselage just behind the engine air inlet on the F-16 Fighting Falcon aircraft. The AGM-88 HARM can be used in three modes of operation; the basic mode of self-protect, prebrief mode or target of opportunity. In the self-protect mode the aircraft radar warning system detects the presence of radar activity in the area, classifies the radar signals by threat type and lethality, calculates the direction to the threat, and displays this information to the pilot. This information is fed to the HARM missile, which is readied for launch. The pilot can launch the missile even if the radar emitter is outside the missile's field of view. When launched, the missile will fly a computer-directed course, acquire the target, lock on and home onto the target radar's emissions and detonate in proximity of the target structure. In the prebrief mode, threat radar locations are selected prior to the mission. After flying to a predetermined location outside the detection range of hostile radar, the pilot can launch the missile and `standoff', while HARM searches out, detects and identifies the targeted radar by its emissions corresponding to the programmed threat parameters, and then attacks the desired threat radar. If the target of opportunity mode is selected the missile's own guidance section detects, locates and classifies threat radar emissions. This information is fed to the cockpit display and provides the aircrew with situation awareness and the necessary data to launch HARM towards the most threatening target. The AGM-88 HARM is credited with a range of 25 km when launched from low level, and of 80 km when launched from medium level (30,000 ft). SPECIFICATIONS :
COMPANY NAME : In effect the HARM programme is lead by the US Naval Air Systems Command, but the system integration contractor is Raytheon Defense Systems, with many other contractors providing assemblies under competitive tender conditions Raytheon Defense Systems, Lewisville, Texas (system integration contractor)
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