ACP-LOGO SCIAMACHY Level1 data : Calibration concept and in-flight calibration

Abstract

This paper discusses the basic concept of the cali- bration of the SCIAMACHY instrument and remaining open issues. SCIAMACHY is a scanning Limb/Nadir spectrome- ter covering the wavelength range from 212 nm to 2384 nm. It was launched onboard ENVISAT in February 2002. In general the instrument performance is excellent: It performes as tested on ground and there is only very minor degradation in time. 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.