
THE ATMOSPHERIC REFRACTION
1. THE CORRECTION
You inputted the apparent zenith distance when, it'll output the true zenith distance.
2. THE UNCORRECTION
You inputted the true zenith distance when, it'll output the apparent zenith distance.
WARNING!
Those calculators are inaccuracy, therefore
Correction(ApparentZ) is TrueZ', and Uncorrection(TrueZ) is ApparentZ',
and ApparentZ isn't ApparentZ', and TrueZ isn't TrueZ'.