[derstosstrupp]

This makes sense. In the meantime, for noon latitude sights (where the problem is most pronounced) your declination numbers for the sun have yielded nearly spot-on results (as you mention, to compensate for the too-high altitude and thus too-low zenith distance). In game I normally get a morning twilight 3-star fix, and then a running fix during the day using a noon latitude sight advanced to another afternoon sun line (normally 3 hours later for a good azimuth change). For the afternoon sun line I always have UT displayed anyway so I can use actual declination (so no issues).

So it’s 2 sets of books for now and that’s OK.

I have also adjusted the diameter of the sun in the mod, mine corresponds to your value of just over a degree.

Thanks for posting that formula also. I will take a closer look at that.