Abstract

Thermography is imaging by means of an infrared camera that detects thermal radiation emitted by all objects, converts the infrared radiation to electrical signals and generates a visible image. Recently developed mosaic infrared detector arrays make possible television displays with scene-temperature sensitivity better than 0.10°C and resolution approaching CCD video cameras. Thermographic cameras that do not require cooled focal planes are becoming the sensors of choice for commercial and private use. Cooled systems having very high sensitivity continue to be developed for military applications. Thermal imaging applications include nighttime surveillance for law enforcement, industrial security, medical diagnostics and rescue operations. Commercial uses are imaging thermal anomalies to find material defects, thermal processing functions and overheating. The combination of thermography with spectral discrimination to achieve spectral imaging is under development for industrial process control and identification of toxic gases such as CO, NO_x, SO_x and ozone. This article includes a mathematical model for thermal imaging sensitivity and spectral discrimination sensitivity.