if you use a SWIR camera stars are pretty visible in the daytime even at ground level. Scattering is related to a fourth power of frequency so by the time you'

if you use a SWIR camera stars are pretty visible in the daytime even at ground level. Scattering is related to a fourth power of frequency so by the time you're down to IR the amount of scattered light is pretty low. (which is also why the sky is blue-- or really UV, if we could see it) The software for plate solving is pretty good. I've had some fun taking movie screenshots and figuring out if the stars are real, and if they're the right hemisphere. (can't be used for location without the time and orientation of the camera)