Overview of the Atmospheric Chemistry Validation of Envisat.

Three atmospheric-chemistry sensors form part of the ENVISAT payload that has been placed into orbit in March 2002 This paper presents the ENVISAT mission status and data policy and reviews the end-to-end performance of the GOMOS MIPAS and SCIAMACHY observation systems and will discuss the validation aspects of these instruments In particular for each instrument the review addresses mission planning in-orbit performance calibration data processor algorithms and configuration reprocessing strategy and product quality control assessment An important part of the quality assessment is the Geophysical Validation At the ACVT Validation workshop held in Frascati Italy from 3-7 May 2004 scientists and engineers presented analyses of the exhaustive series of tests that have been run on each of ENVISAT atmospheric chemistry sensors since the spacecraft was launched in March 2002 On the basis of workshop results it was decided that most of the data products provided by the ENVISAT atmospheric chemistry instruments are ready for operational delivery Although the main validation phase for the atmospheric instruments of ENVISAT will be completed soon ongoing validation products will continue throughout the lifetime of the ENVISAT mission The long-term validation phase will begin itemize item Provide assurance of data quality and accuracy for applications such as climate change research item Investigate the fully representative range of geophysical conditions item Investigate the fully representative range of seasonal cycles item Perform