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Last updated - Dernière modification 21/11/08 Mines ParisTech - Armines |
FAQ about HelioClim Databases of Solar Radiation
FAQ - Ground measurements and HelioClim
FAQ_G_HC3. Fusing on-site measurements and HelioClim data. I have ground measurements together with HelioClim data within a common period. What is the best way to fuse them?
A. If the measurements are well made with a well calibrated instrument, the ground measurements are supposed to better represent the reality than HelioClim. The principle is to adjust HelioClim data onto ground measurements. One way to do that is to compute a regression line between ground measurements and HelioClim data. One may use least-square method or alternatively the first axis of inertia method.
FAQ - Using coincident data from two different HelioClim databases
FAQ_G_HC3. Fusing data from two different HelioClim databases. I have data from two different HelioClim databases within a common period, typically HC-1 and HC-3, with a common period 2004-2005. What is the best way to fuse them?
A. Various validation experiments between HC databases and ground measurements have shown that HC-3 data are closer to actual values than HC-1. Thus, HC-3 data have less uncertainty than HC-1. The principle is to adjust HC-1 data onto HC-3 data for the common period. One way to do that is to compute a regression line between HC-1 and HC-3 data. One may use least-square method or alternatively the first axis of inertia method. Then, the relationship may be applied to the whole series of HC-1 data, thus offering a consistent data set from 1985 till nowadays.