Employed on helicopters and transport aircraft, the AN/AAR-47 Missile Approach Warning System (MAWS) warns of threat missile approach by detecting radiation associated with the rocket motor and automatically initiates flare ejection. The AN/AAR-47 is a passive Electro-Optic Missile Warning System designed to provide warning of Surface to Air Missiles (SAMS) and pass information to countermeasures systems.Detection algorithms are used to discriminate against non-approaching radiation sources. The AN/AAR-47 system is similar to the AN/AAR-44, but instead of a revolving sensor unit it uses four IR sensors located in four quadrants on the Aircraft. The AAR-47 is a passive, missile- approach warning system consisting of four sensor assemblies housed in two or more sensor domes, a central processing unit, and a control indicator. The Warning System provides attacking missile declaration and sector direction finding and will be interfaced directly to the countermeasures dispenser. Without the AAR-47, helicopters and fixed-wing aircraft have no infrared missile detection system.
Credits and References:
1) http://www.fas.org/man/dod-101/sys/ac/equip/an-aar-47.htm