Thermal imaging is superior to light amplification (night vision) in that it requires no light and is completely unaffected by bright light. Camouflage, dark clothing and partial concealment can easily affect night vision, but is rarely effective against thermal imagers. Tactical teams can use thermal imagers for a variety of applications, including pre-entry surveillance, stealth entry, search, evidence-collection and even scene size-up. Fugitive searches are enhanced when conducted with a thermal images.
Thermal imaging mostly used for night vision. The camera detects heat radiated by human bodies, animals, machines and other heat sources, which, in turn, returns an image that reflects the size, shape and intensity of the heat source. Military operations typically use night vision to direct their efforts when trying to navigate nighttime terrain without being detected.
During crime scene investigations, the thermal imager can aid in the recovery of evidence that may be hard to detect with a flashlight and the human eye. Hotter objects, such as recently fired weapons or ejected shell casings, should generate stronger thermal images. In the Fairfield County situation, the thermal imager not only located the armed suspect, but it also helped officers locate the weapons.
Human Body Anomalies
If a person is ill and agitated, his body will produce heat in its attempt to fight off infection, and a camera may be able to pinpoint the source of the infection. Also, if there is the presence of an abnormal object in the human body, whether it be a swallowed object or something the person is attempting to smuggle, the disparity in the heat given off by the object versus the body’s normal tissue temperature will show up in the image returned by the camera.
With a thermal imager, officers have the ability to see the suspect’s body heat, which makes it very difficult for the suspect to conceal his position, whether he is hiding inside of a structure or outdoors.