Infrared thermography, thermal imaging, thermographic imaging, or thermal video, is a type of infrared imaging science. Thermographic cameras detect radiation in the infrared range of the electromagnetic spectrum (roughly 900-14,000 nanometers or 0.9-14 µm) and produce images of that radiation, called thermograms. Infrared light is part of the same electromagnetic spectrum as visible light, but it is not visible to the human eye. Since infrared radiation is emitted by all objects near room temperature, thermography makes it possible to "see" one's environment with or without visible illumination.
Infrared light is associated with heat and is emitted by all objects at temperatures above absolute zero. Specialized equipment can detect infrared light and display it as a visible image for analysis and interpretation. The amount of radiation emitted by an object increases with temperature, therefore thermography allows one to see variations in temperature (hence the name). Our infrared thermography camera uses the same basic technology as military and scientific devices.
AKARI, A High-Capability Infrared Satelite Presents 1st Detailed Map of Our Universe In Infrared Light