For signature reduction in general see Stealth technology.

The term infrared signature is used by defense scientists and the military to describe the appearance of objects to infrared sensors. An infrared signature depends on many factors, including the shape and size of the object, temperature and emissivity, reflection of external sources (earthshine, sunshine, skyshine) from the object's surface, the background against which it is viewed and the waveband of the detecting sensor. As such there is no all-encompassing definition of infrared signature nor any trivial means of measuring it. For example, the infrared signature of a truck viewed against a field will vary significantly with changing weather, time of day and engine loading.