Atmospheric Properties#
For most cases the plane-parallel atmosphere method works, and it is what this function uses. However, we also use a more accurate formula for airmass at higher zenith angles (>80 degree), namely from DOI:10.1364/AO.28.004735. We use a weighted average between 75 < z < 80 degrees to allow for a smooth transition.
index of refraction as found found in DOI: 10.1088/0026-1394/30/3/004.