Anti-radiation missileaircraft also carry cluster bombs, which can be used to ensure that, after the ARM disables the SAM system’s radar, the command post, missile launchers, and other components or equipment are also destroyed to guarantee that the SAM site stays down. Early ARMs, such as the AGM-45 Shrike, were not particularly intelligent; they would simply home in on the source of radiation and explode when they got near it.[3] SAM operators learned to turn their radar off when an ARM was fired at them, then turn it back on later, greatly reducing the missile’s effectiveness. This led to the development of more advanced ARMs like the AGM-78 Standard ARM and AGM-88 HARM missiles, which have inertial guidance systems (INS) built-in. This allows them to remember the radar’s direction if it is turned off and continue to fly towards it. ARMs are less likely to hit the radar if the radar is turned off shortly after the missile is launched, as the longer the radar is off (and assuming it never turns back on), the more error is introduced into the missile’s course. The ALARM even has an added loiter mode, with a built in parachute, enabling it to descend slowly until the radar lights up, when the rocket motor will re-ignite. Even a temporary shut down of the enemy’s missile guidance radar can be of a great advantage to friendly aircraft during battle. HARM on a US Navy F/A-18C 2 Surface-to-surface ALARM under the wing of a Tornado Several surface-to-surface missiles, like the Hormoz, P700 Granit, P-500 Bazalt, MM40 Exocet, B611MR, and Otomat, include a home-on-jam capability wherein the receiver component of their active radar homing is used to home in on enemy radar, ECM or communications. This makes these missiles significantly harder to defeat with ECM and distraction countermeasures, and makes the use of semi-active missiles against them dangerous. An anti-radiation missile (ARM) is a missile designed to detect and home in on an enemy radio emission source.[1] Typically, these are designed for use against an enemy radar, although jammers[2] and even radios used for communications can also be targeted in this manner. 1 Air-to-surface 3 Surface-to-air Most ARM designs to date have been intended for use against ground-based radars. Commonly carried by specialist aircraft in the Suppression of Enemy Air Defenses (SEAD) role (known to the United States Air Force as "Wild Weasels"), the primary purpose of this type of missile is to degrade enemy air defenses in the first period of a conflict in order to increase the chances of survival for the following waves of strike aircraft. They can also be used to quickly shut down unexpected surface-to-air missile (SAM) sites during an air raid. Often, SEAD escort Due to experiences with jamming by US-built aircraft in Vietnam and during Middle Eastern wars in the late 1960s, the Soviets designed an alternative tracking mode for their S-75 (SA-2) missiles, which allowed them to track a jamming target without needing to actively send out any radar signals. This was achieved by the SAM site’s radar receiver locking on to radio noise emissions generated by an aircraft’s jamming pod. In cases of 1 Retrieved 2006-07-10. it was meant to offer an air-to-air capability against proposed Soviet AWACS types and also some other types with extremely powerful radar sets. air-to-air ARM designs have begun to appear. the People’s Republic of China developed the FT-2000 system to counter AEW and AWACS targets. Recently. These anti-radiation missile systems have been marketed to Pakistan and various other countries.2 5 heavy jamming. [3] http://www. notably the Russian Vympel R-27EP. such as the MiG-25. Hughes Aerospace had a project called BRAZO (Spanish for ARM). they do not trigger radar warning receivers (conferring a measure of surprise). Archived from the original on 2006-06-14. and they can have a longer range (since the battery life of the seeker head is the limiting factor to the range of most active radar homing systems). this passive tracking meant that SAM sites could track targets without needing to emit any radar signals. In the 1970s.net/dusrm/m-45. The project did not proceed. ironically. and so American anti-radiation missiles could not be fired back in retaliation. Retrieved 20 May 2014. missiles were often launched exclusively in this mode.html • Reuben Johnson (February 2006).designation-systems. Based on a Raytheon AIM7 Sparrow. 5 References [1] “Raytheon Company: High-Speed Anti-Radiation Missile (HARM)". • Russian site on the S-75 from Said Aminov “Vestnik PVO” (Russian) Google translation REFERENCES . Asian Aerospace. “Improved Russian radar may level playing field”. [2] “AGM-88 HARM”. which is in turn based on the S-300PMU. This system is based on the HQ-9. Such missiles have several advantages over other missile guidance techniques. 4 Air-to-air More recently. Retrieved 20 May 2014. Original artist: Benjamin D. Sietse Snel. Guidosst. Finster. Karolrvn. Trappist the monk. Mrt3366. Kivaan.jpeg License: CC BY-SA 2. Los688. Vina-iwbot~enwiki. Gaius Cornelius. Tomdo08. Kostmo. based upon Text-x-generic. Joshbaumgartner. BilCat.S.org/wikipedia/commons/a/a4/Text_document_ with_red_question_mark. Delirium. VolkovBot. Avriette.svg Source: https://upload. XB-70. • File:ALARM. DocWatson42. Glevum. Makecat-bot. Dammit. ImageRemovalBot. Magioladitis. Smsarmad. Bubbleboys. 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