The new refraction code in afw has many functions that claim to return float, but actually return astropy Quantity.

This has two issues:

• The code in refraction is hard to understand because atmosTerm1 and 2 have units of Pa / mbar but they are supposed to be dimensionless. It's hard to see how one gets radians from that. For clarity I think some values should be converted to floats instead of being left as Quantities.
• The documented return value is wrong for many of the functions.

I stumbled across this while implementing DM-14429 and had some trouble figuring out what was going on.