Problems with refraction
Some weird things are going on with Joern's refraction calculations. When calculating the refraction at default values for 10 degrees distance to the zenith the result is
isis> refraction(10; deg);
0.2953773007997269
which seems very much to me. When using the "exact" qualifier the value changes by ~50%:
isis> refraction(10; deg, exact);
0.19115844986094963
When calculating with the "exact" qualifier for different wavelength at 10 degrees this happens: