Infrared tracking, also known as <answer>infrared</answer> homing, refers to a passive missile guidance system, which uses the emission from a target of electromagnetic radiation in the <answer>infrared</answer> part of the spectrum to track it. Missiles that use <answer>infrared</answer> seeking are often referred to as "heat-seekers", since <answer>infrared</answer> (IR) is just below the visible spectrum of light in frequency and is radiated strongly by hot bodies. Many objects such as people, vehicle engines, and aircraft generate and retain heat, and as such, are especially visible in the <answer>infrared</answer> wavelengths of light compared to objects in the background.
What does IR stand for?
infrared