SCIAMACHY on ENVISAT: in-flight optical performance and first results

The Scanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) is a contribution to the ENVISAT-1 satellite, which has been launched in March 2002. The SCIAMACHY instrument measures sunlight transmitted, reflected and scattered by the Earth's atmosphere or surface simultaneously from the UV to the SWIR spectral region (214 - 2380 nm) in nadir, limb, and occultation viewing geometry. SCIAMACHY allows the characterisation of the composition of the Earth atmosphere from the ground to the mesosphere. This paper gives an overview of the SCIAMACHY instrument and its in-flight detector, spectral and radiometric performance. Furthermore first results on trace gas retrieval from limb and nadir measurement mode will be summarised.