Introduction

Last update: Sept. 2016

 

CAMS services are composed of two services: CAMS radiation service and CAMS McClear.    >> Brief description of these services


 

The method Heliosat-4 processes Meteosat images to create the CAMS radiation service. Consequently, CAMS radiation service covers Europe, Africa, the Mediterranean Basin, the Atlantic Ocean and part of the Indian Ocean (-66° to +66° both in latitude and longitude).

 

CAMS radiation service delivers spectrally-integrated 15 minute Global Horizontal Irradiance (GHI) and Direct Normal Irradiance (DNI) values.

 

Heliosat-4 contributes to a detailed assessment of optical variables in the atmosphere (gaz, aerosols, water vapour), clouds and ground albedo. One of the major results is the clear-sky model McClear that estimates the radiation that should be received if the sky were clear anywhere, since 2004, available worldwide. This model has been created by the Centre O.I.E., the  DLR, the Finnish Meteorological Institute), and the  European Center for Medium-range Weather Forecasts ECMWF.

 

NB: The reliability variable is computed with respect to the amount of 1 minute resolution time slots of the current time slot (15 min or 1 hour) without cloud information. In the morning and evening, for very low sun elevation angles, the APOLLO cloud computation gives no results, and this explains the value lower than 1 for the first/last 15 min (or 1 hour) slot in the morning/evening. During the day, it happens from time to time that the cloud information cannot be computed for a given satellite images set and this also creates a lower reliability value (this can be cause by a problem in the satellite images reception or in the APOLLO computing process - CAMS radiation is still a bit "experimental"). Thus, in summary, the reliability value gives an idea of the amount of interpolated data for the time slot of interest.