An infrared countermeasure (IRCM) is a device designed to protect aircraft from infrared homing missiles by confusing the missiles' infrared guidance system so that they miss their target. Heat-seeking missiles were responsible for about 80% of air losses in Operation Desert Storm. The most common method of infrared countermeasure is deploying flares, as the heat produced by the flares creates hundreds of targets for the missile.
BAE Hot Brick infrared jammer
Sukhoi Su-27 shoots off false heat targets
C-130 Hercules deploys flares, sometimes called angel flares because of their characteristic pattern
An ALQ-144 modulated IRCM jammer
Infrared homing is a passive weapon guidance system which uses the infrared (IR) light emission from a target to track and follow it seamlessly. Missiles which use infrared seeking are often referred to as "heat-seekers" since infrared is radiated strongly by hot bodies. Many objects such as people, vehicle engines and aircraft generate and emit heat and so are especially visible in the infrared wavelengths of light compared to objects in the background.
A modern German Air Force IRIS-T infrared homing air-to-air missile
The Vampir nightscope used a photomultiplier as the sighting system and provided illumination with an IR lamp mounted above the scope.
The Madrid seeker was being developed for the Enzian surface-to-air missile.
The AIM-4 Falcon was the first IR guided missile to enter service. The translucent dome allows the IR radiation to reach the sensor.