The objective of the SCIAMACHY validation is to determine the accuracy of operational and scientific data products for all relevant atmospheric conditions. This will be achieved by comparison of the SCIAMACHY data products with temporally and spatially coincident measurements performed by independent instrumentation from various platforms.
Organisation
The validation of SCIAMACHY is organised within two complementary structures. From ESA side, approved projects dealing with the validation of SCIAMACHY, GOMOS and MIPAS were gathered in the Atmospheric Chemistry Validation Team (ACVT). ESA-Approved projects were financed by the national agencies, in the case of SCIMACHY by the space agencies of Germany, the Netherlands and Belgium. The SCIAMACHY Science Advisory Group (SSAG) has established the SCIAMACHY VALidation and Interpretation Group (SCIAVALIG). Within SCIAVALIG, a list of requirements for the validation has been setup and a core validation programm has been defined. A organisational structure for the continuous monitoring of validation results throughout the lifetime of SCIAMACHY has been set up.
Correlative measurements
The main validation phase for the atmospheric chemistry instruments on-board Envisat (mid 2002 to mid 2003) was a period with intensive validation campaigns, including big balloon and aircraft campaigns. Numerous of groundbased stations with a broad range of instrument types have been set up, most of them are still operational. Existing instruments and networks are continously used also for the validation of SCIAMACHY. Global validation by using measurements of a long list of already validated satellite missions (including SCIAMACHY's ancestor GOME) has been and is a very successful tool. All correlative measurements are collected on the validation database, operated by the Norwegian Institute for Air Research (NILU) on behalf of ESA. Therefore all collected data can be used through the lifetime of the instrument to ensure the quality of all new or updated products.
German/Bremen contribution
The German contribution to the validation SCIAMACHY (http://www.iup.physik.uni-bremen.de/gcvos/) comprised 20 projects with more than 60 scientists involved in the 2001 to 2004, almost half of them were located at the University of Bremen. The four pillars of the German validation activities were:
