Horizon Investigation

[STSpencer]

This is an issue to discuss NSB at the horizon, as was mentioned on this morning's analysis call.

Purely by coincidence, I happened to run an NSB run on the horizon yesterday, as I was curious as to what would happen and the potential difference across the camera plane. Here are the results, which are at the same time as the latest 'half moonlight' runs with az at 90 degrees and alt 0:

Clearly the field rotation is still an issue, as in #14 . Full results can be found in the ../results/horizon directory of this repo. Curiously enough, NSB doesn't just crash flat out like it did for pointing directly at the moon.

Obviously this doesn't take any light pollution from population areas; I've absolutely no idea how or if it's possible to model this. Perhaps the best option would be to reach out to the southern site manager and see if we can get some real all sky camera data that we could then compare to NSB.