SCIAMACHY In-flight Instrument Performance

Abstract

On 1st of March 2002 ENVISAT with SCIAMACHY on-board was launched successfully in a sun-synchronous polar orbit. SCIAMACHY is a passive remote sensing instrument, which measures solar back scattered and reflected light from the atmosphere in nadir and limb viewing geometries during the majority of an orbit. In addition solar and lunar occultation measurements will be performed regularly. Measurements are made with moderate spectral resolution (0.2 – 1.5 nm) simultaneously in eight spectral channels covering the spectral region between 240 and 2380 nm. After a few weeks of out gassing SCIAMACHY was switched on successfully and a complex procedure starts to check out the instrument in orbit and tune it to the optimum in-flight performance. Solar and atmospheric spectra were already taken since the begin of April 2002. During SODAP and commissioning phase the instrument functional and optical performance was verified and instrument calibration activities were started. These activities revealed that SCIAMACHY is performing well and as expected from on-ground calibration, with only on exception: the water ice condensation in channels 7 and 8. Nevertheless for this problem countermeasures are identified. This paper summarizes the status of SCIAMACHY after 6 month in orbit, with a major focus on the optical and pointing performance.