Enter name of the site:
Enter latitude of the site: (Use positive values for northern latitudes, negative values for southern latitudes.)
Enter date for radiation estimate: January February March April May June July August September October November December 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Year:
The default solar constant (Jo) is: W m^-2 You may keep this value or enter a new one.
The default atmospheric transmissivity (a) is: You may keep this value or enter a new one.
The default atmospheric emissivity (AtmEmiss) is: You may keep this value or enter a new one.
The default surface emissivity (SurfEmiss) is: You may keep this value or enter a new one.
The default atmospheric equilibrium temperature (AtmTemp) is: K You may keep this value or enter a new one.
Select the albedo: Average Earth (0.297) Urban (0.160) Cropland (0.200) Forest (0.143) Grassland (0.215) Desert (0.275) Tundra (0.250) Ice (0.325) Snow (0.675) Water (0.100) (Choose the value that corresponds with the type of surface you want to model.)
Enter the elevation of the site in meters:
Enter the aspect of the site in degrees: (This doesn't need to be changed for a flat surface.)
Enter the slope angle of the site: Is this figure in degrees or percent? (This doesn't need to be changed for a flat surface.)
Enter east horizon elevation in degrees: (This doesn't need to be changed for a flat surface.)
Enter west horizon elevation in degrees: (This doesn't need to be changed for a flat surface.)
Now we need to determine the elevation of the horizon between the site and the sun at noon.
Enter noon-sun horizon elevation in degrees: (This doesn't need to be changed for a flat surface.)