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Last updated - Dernière modification 4/03/09 Mines ParisTech - Armines |
Uncertainty of the HelioClim-1 Database of Solar Radiation
The uncertainty has been assessed by comparisons with measurements performed in several stations of the radiometric networks in Europe and Africa. The natural variability of the radiation should be removed from the values below (approx. 10-15 %) to evaluate the accuracy of the database.
Results of the comparisons have been published (see articles). They are used to compute the uncertainty that is delivered with each radiation value.
VERSION 3.0. Assessed by comparisons with measurements of the WMO radiometric network in Europe (55 sites) and Africa (35 sites) for the period 1994 - 1997. See articles.
| Mean value of ground data | Bias (HC - ground) | RMSE (root mean square error) | |
|---|---|---|---|
Daily
Values |
4848 Wh/m2 17453 kJ/m2 202 W/m2 |
24 Wh/m2 86 kJ/m2 1 W/m2 |
840 Wh/m2 3024 kJ/m2 35 W/m2 |
Monthly
Means of Daily Values |
4848 Wh/m2 17453 kJ/m2 202 W/m2 |
24 Wh/m2 86 kJ/m2 1 W/m2 |
600 Wh/m2 2160 kJ/m2 25 W/m2 |
5-days
Sums |
22.6 kWh/m2 81.5 MJ/m2 |
0.1 kWh/m2 0.4 MJ/m2 |
3.2 kWh/m2 11.6 MJ/m2 |
10-days
Sums (pentads) |
45.4 kWh/m2 163.3 MJ/m2 |
0.2 kWh/m2 0.7 MJ/m2 |
6.0 kWh/m2 21.7 MJ/m2 |
Monthly
Sums |
145 kWh/m2 497 MJ/m2 |
0.7 kWh/m2 2.6 MJ/m2 |
17 kWh/m2 60 MJ/m2 |
VERSION 4.0. Assessed by comparisons with measurements of the WMO radiometric network in Europe and Middle East (80 sites) and Africa (75 sites) for the period 1985-2005.
See graphs for