Infrared (IR) imaging is the remote sensing of the spatial and time variations in the intensity of IR radiation emitted or reflected from a scene. The applications are mainly military (missile seekers, reconnaissance and surveillance, target detection and tracking ...), industrial, geologic and medical. The ever increasing demands on the performances of military thermal imaging has contributed to a growing effort devoted to sensors in the last 10 years, leading to the implementation of solid state focal plane arrays (FPAS). The key issue was to achieve a large number of sensitive IR detectors and readout circuits with uniform photoresponse and large signal to noise ratio to approach Background LImited Performances (BLIP).
M. Rieux, M. Rieux,
"Recent Developments In Infrared Detectors", Proc. SPIE 0702, International Topical Meeting on Image Detection and Quality, (18 May 1987); doi: 10.1117/12.966717; https://doi.org/10.1117/12.966717