Recent Advances In Testing Of Thermal Imagers

A thermal imager undergoes several different types of test in its final assembled form in order to ascertain that it performs to specification. The actual measurements made on the imager will depend to a certain extent on the use for which it is intended. Where imagers are to be used in applications such as surveillance and navigation, in which a human observer views the final image, the measurement of minimum resolvable temperature-difference (MRTD) is both relevant and customary. The MRTD provides data which can be used to predict performance in terms of the temperature-difference and range at which specific targets can be identified with a given probability. It is a subjective measurement and its value lies in the fact that it assesses the combination of imager and observer. Its main disadvantage is the variability in measured results which arises from its subjective nature.