|To image at low temperatures you need a system in longer wavelenghts and with high Quantum Efficiency. A microbolometer based system won't have enough sensitivity. A QWIP system won't work either. However a LWIR Mercury Cadmium Telluride system can work quite well to real cold temperatures. I have data taken with an Electrophysics Jade LWIR system (7.7-9.5um) that measures temperature well below <150C. With an Electrophysics Jade VLWIR (7.7-11.0um) we estimate we can measure even lower. We will do some testing, coincidentally, at a government lab to see "how low we can go."