Status of the ENVISAT Atmospheric Chemistry Mission
Thorsten Fehr(1), Gilbert Barrot(2), Heinrich Bovensmann(3), Miguel Canela(4), Angelika Dehn(5), Roland Gessner(6), Manfred Gottwald(7), Henri Laur(1), Fabrizio Niro(5), Gaetan Perron(8), Piera Raspollini(9), Lidia Saavedra de Miguel(5), ESA PLSO Team(10), GOMOS Quality Working Group(10), MIPAS Quality Working Group(10) and SCIAMACHY Quality Working Group(10)
(1) ESA, Via Galileo Galilei, 00044 Frascati, Italy
(2) ACRI-ST, Route du Pin Montard 260, 06904 Sophia-Antipolis, France
(3) IFE/University of Bremen, , 28334 Bremen, Germany
(4) ESA, Keplerlaan 1, 2201 AZ Noordwijk, Netherlands
(5) SERCO, Via Sciadonna 24, 00044 Frascati, Italy
(6) EADS ASTRIUM GmbH, , 88039 Friedrichshafen, Germany
(7) DLR-IMF, Münchner Str. 20, 82234 Oberpfaffenhofen, Germany
(8) ABB, 585 Charest Blvd., Québec, Québec G1K9H4, Canada
(9) IFAC/CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy
(10) , , ,
Three instruments on-board the ESA Envisat satellite are focussing on atmospheric chemistry, providing a rich dataset to the scientific community and supporting operational services. With the observations of GOMOS, MIPAS and SCIAMACHY trace gases and chemical processes within the complete atmosphere can be investigated, covering pollution, long term trends of GHGs, stratospheric ozone, mesospheric and thermospheric processes and beyond.
To provide quality data to the users, a complex process chain involving the spacecraft, the instruments and the ground segment must be monitored and maintained. This requires the constant development of the system to respond to new boundary condition.
This paper focuses on the past, present and future of the GOMOS, MIPAS and SCIAMACHY instruments and ground segment (the overall Envisat Status and mission extension will be discussed in a separate paper). Since launch of the mission in 2002, all of the instruments have been going through significant developments. GOMOS was encountering some periods with anomalous instrument behaviour, limiting the overall selection of star occultations. At the same time, the processing was improving the overall data quality. Problems on MIPAS in 2004 resulted in a change of the overall instrument operations. Through corresponding optimisations and the overall recovery of the instrument, the mission is again fully operational. However, difficulties with the data processing were encountered. The SCIAMACHY is one of the most reliable instruments on ENVISAT. Nevertheless, the operational data processing has gone through important improvements, both on the Level 1b and Level 2 side. Following seven year of operations, all instruments are suffering from expected degradation effects. As ESA is preparing a possible extension of the ENVISAT mission to end of 2013, these effects have to be carefully evaluated. The potential impact on the data quality through the extension period will also be discussed.