Calibration approaches and quality aspects for the ENVISAT Atmospheric Chemistry instruments

ENVISAT carries on-board the three Atmospheric Chemistry instruments GOMOS, MIPAS and SCIAMACHY. These instruments use different measurement techniques and observation geometries for atmospheric remote sounding. All of them require regular calibrations permitting to account for long term degradation of instrument performances or for short term variation of measurement conditions. This paper gives an overview on the most relevant calibration aspects of the three instruments and illustrates how to improve calibration for an even higher data quality.