A lot of people are going thermal sensor crazy right now with the application of screening people for fever. I was asked to research it a bit for my company and I two weeks reading papers, googling, and talking to sensor manufacturers. I've found a range of sensors, from expensive $9k-$5k sensors that show 0.1C real temperature data for every pixel, to $200 sensors that have a +/- 5C accuracy. I was sitting here thinking about if there was a way to get better accuracy on the cheaper sensors. My assumption is the +/-5C comes from sensor noise, so it's not like an offset that drifts with ambient temperature, but more of a it might be 5C low this frame and +5C on the next frame. Not sure if I'm right there. But then I've seen sensors with more accurate spot meters in the middle and I was wondering if those can be used to correct for the error? I was thinking about trying to use an external accurate spot meter too but I guess it wouldn't be in sync with the noise.
Anyway my real question is, given a sensor like say the sub $200 FLIR lepton 3.5 who has a radiometric accuracy or +/-5C, is there a technique or circuit design to improve that accuracy? I know component questions are off topic but if there is another type of sensor I should be looking at I'd appreciate any suggestions. For context I have some AR glasses and they can let you "see" in thermal vision using external sensors. And I'm looking for an inexpensive solution that would let them be more widely deployed (as opposed to the $9k camera option).