| Relative optical
airmass |
| Pressure-corrected airmass |
| Solar zenith
angle, degrees from zenith, refracted |
| Solar azimuth
angle |
| Cosine of solar
incidence angle on panel |
| Cosine refraction
corrected solar zenith angle |
| Solar elevation
(no atmospheric correction) |
| Solar elevation
angle (degrees from horizon, refracted) |
| Extraterrestrial
Global Horizontal Solar Irradiance (W/m2) |
| Extraterrestrial
Direct Normal Solar Irradiance (W/m2) |
| Extraterrestrial
Global Irradiance on a tilted surface (W/m2) |
| Sunrise time,
minutes from midnight (local w/o refraction) |
| Sunset time,
minutes from midnight (local w/o refraction) |
| Shadow-band
correction factor |
| Factor that
normalizes Kt, Kn, etc. (prime) |
| Factor that
normalizes Kt', Kn', etc. (unprime) |