1SRON National Institute of Space Research, Utrecht, the Netherlands
2Royal Netherlands Meteorological Institute (KNMI), de Bilt, the Netherlands
3Institute of Remote Sensing (IfE), University of Bremen, Germany
4TNO Science and Industry, Delft, the Netherlands
5DLR-DFD/IMF, Weßling, Germany
7Harvard-Smithsonian Center for Astrophysics (SAO), Cambridge, USA
*now at: Royal Meteorological Institute Netherlands (KNMI), de Bilt, the Netherlands
Abstract. This paper discusses the basic concept of the calibration of the SCIAMACHY instrument and remaining open issues. SCIAMACHY is a scanning Limb/Nadir spectrometer covering the wavelength range from 212 nm to 2386 nm. It was launched on-board ENVISAT in February 2002. In general the instrument performance is excellent: It performs as tested on ground and there is only very minor degradation in time. The only exception is the unexpected formation of water ice on the infrared channels 7 and 8 that attenuates the signal and a light leak in channel 7. Both effects will be discussed. In the paper we will explain all individual calibration steps needed to come to a wavelength calibrated spectrum of the Earth reflectance. Open points in the calibrations and latest improvements, such as the new radiometric calibration will also be treated.