The reported Noise Equivalent Temperature Difference (NEdT) for a Tau 320 camera is <50mK at f/1.0. This can be translated to change in power per unit area to yield that the minimum resolvable change in flux is <0.14 watts / sq meter at f/1.0.
Note that this calculation makes the following assumptions:
· An entire pixel is filled with the target.
· The target temperature is ~300K with unity emissivity.
· Medium of space neglects atmospheric attenuation and is independent of distance as long as the pixel is filled.
· The f/# of the lens is 1.0. Any f/# can be calculated by multiplying the result by (desired f/#)^2.
· Only signal between 7.5 and 13.5 microns will reach the detector.