Infrared homing

Infrared homing is a passive weapon guidance system which uses the infrared (IR) light emission from a target to track and follow it. 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 as such, are especially visible in the infrared wavelengths of light compared to objects in the background.