| constant | cAltitude | elevation above sea level | DOUBLE | m | - | - | 0.0 |
| constant | cAngstromRegressionConstant | Angstrom equation regression constant | DOUBLE | 1 | - | - | 0.25 |
| constant | cAngstromRegressionSlope | Angstrom equation regression slope | DOUBLE | 1 | - | - | 0.5 |
| constant | cLatitude | latitude | DOUBLE | ° | -90.0 | 90.0 | 0.0 |
| constant | cUseAngstromVariables | use measured Angstrom variables if true, else use default ones | BOOLEAN | | - | - | false |
| input | iActualVapourPressure | actual vapour pressure | DOUBLE | kPa | - | - | 0.0 |
| input | iSunHours | actual duration of sunshine | DOUBLE | h | 0.0 | 24.0 | 0.0 |
| input | iTMax | maximum daily temperature | DOUBLE | °C | - | - | 0.0 |
| input | iTMin | minimum daily temperature | DOUBLE | °C | - | - | 0.0 |
| ExtraterrestrialRadiation | extraterrestrial radiation | DOUBLE | MJ/(m2 d) | null |
| NetOutgoingLWRadiation | net outgoing longwaveRadiation | DOUBLE | MJ/(m2 d) | null |
| NetRadiation | net radiation | DOUBLE | MJ/(m2 d) | null |
| NetSolarRadiation | net solar or shortwave radiation | DOUBLE | MJ/(m2 d) | null |
| SolarRadiation | solar or shortwave radiation | DOUBLE | MJ/(m2 d) | null |