HelioSat-2 |
A problem of units ? of terminology ? Consult the Education service. |
Principle of acquisition of the MSG images
1_ the images acquired by the Meteosat satellite are sent toward the central ground station of Eumetsat (the provider of the MSG images) located in Darmstadt in Germany. The MSG images undergo geometrical rectifications as well as radiometric calibration. 2_ Once corrected, the images are transmitted back onto Meteosat platform. 3_ Meteosat forward the images to a satellite located in its neighbourhood: Hotbird. 4_ At last, this satellite Hotbird takes care of the dissemination of the images toward the individual ground station reception dishes using a video channel. |
 Steps for the acquisition of the MSG images |
Steps of the HelioSat2 method
(Coming soon, with the equations and useful references)
le point faible de cette méthode est par exemple le modèle de ciel clair, ou modèle de turbidity qui est estimé à partir de données climatiques, c'est-à- dire qu'elles n'évoluent pas au cours du temps. L'idée de heliosat-4 est d'avoir un meilleur modèle de ciel clair qui dépend du temps.
HS-2 est basée sur deux modèles successifs: le premier décompose le global horizontal en direct et diffus, et le second permet d'obtenir les composantes sur plan incliné. Le modèle qui permet d'obtenir le diffus est celui de Muneer qui est un modèle non isotrope, qui donne la répartition angulaire de la diffusion. Le futur HS-4 permettra d'estimer directement les composantes directe et diffuse, pas seulement le global horizontal.
Enfin, HS-2 a l'inconvénient d'être une estimation broadband du global horizontal. HS-4 sera capable de donner un GHI qui ne soit pas intégré spectralement. Sera fonction de la longueur d'onde.
Historic and future
HelioSat-1:
HelioSat-2:
Setting up the heliosat-2 method. This method converts observations made by meteorological geostationary satellites: Meteosat, GOES, GMS, GOMS, Insat, FY, into measures of shortwave radiation impinging on the ground. The software libraries are freely available. Owing to the SoDa Service, one may check the correct implementation of the libraries for the sun geometry and the radiation under clear skies. One may also check the correct reading of the values of the Linke turbidity factor and altitude of the terrain. Date: November 2002.
HelioSat-3: University of Oldenburg
HelioSat-4:
The operational phase of HelioSat-4 is planned for Nov 2013. It will start with a first period of 9 months, with input data from ECMWF, DLR et NASA. Meanwhile, the development and the validation of all the elements are carried out. An implementation of the operational chain in a data center under the supervision of Transvalor is contemplated.
Last update: 3/14/12 11:23 AM