If you are warm, any warm-detectors inside your body will detect mostly you. Imagine if blood vessels in your own eye radiated in visible spectrum with the same intensity as daylight environment.
It‘s possible to filter out a constant high value, but not possible to filter out a high level of noise. Unfortunately warmth = random vibration = noise. If you want a low noise thermal camera, you have to cool the detector, or only look for hot things, like engine flares. Fighter planes do both.
If you are warm, any warm-detectors inside your body will detect mostly you. Imagine if blood vessels in your own eye radiated in visible spectrum with the same intensity as daylight environment.
Can’t you filter that out? .
How do fighter planes do it?
It‘s possible to filter out a constant high value, but not possible to filter out a high level of noise. Unfortunately warmth = random vibration = noise. If you want a low noise thermal camera, you have to cool the detector, or only look for hot things, like engine flares. Fighter planes do both.