(IR) a photograph-like image created by optical-electronic equipment using the infrared wavelengths of the electromagnetic spectrum —note 1. fire IR imagery is used through dense smoke, haze, and vegetative canopy to (a) detect the incidence of wildfires in remote terrain, especially following lightning storms, (b) map the perimeters, hot spots, and spot fires of going fires, and (c) detect residual heat sources during mop-up; generally, the first two uses employ IR scanners in aircraft while the third uses hand-held IR scanners on the ground or in slow-flying helicopters —note 2. fire IR imagery is not cost effective through fog, rain, or other moisture —synonym heat probe, thermal imagery This definition last updated 10/28/2008