MetOp will provide continuity to existing measurements and it will carry novel instruments that have never been flown on operational satellites before. The instruments well-known from NOAA are the ATOVS suite including a HIRS, AMSU-A and the MHS (microwave humidity sounder) contributed by EUMETSAT and already flying on NOAA-18 in an afternoon orbit. As for the operational imager MetOp relies on the well-known AVHRR series. Ocean surface winds are measured with an advanced scatterometer (ASCAT) measuring the backscatter of the ocean surface on both sides of the orbital track. The Global Ozone Monitoring Experiment (GOME-2) provides primarily ozone measurements (total column and profiles) and in addition information on aerosol and other trace gases. The Global positioning system Receiver for Atmospheric Sounding (GRAS) mission is the first operational meteorological radio-occultation measurement. Recent impact studies performed at ECMWF have highlighted the potential of those measurements to improve the numerical weather forecasts. Last but not least the Infrared Atmospheric Interferometric Sounder (IASI) is an advanced hyperspectral sounder resolving the thermal infrared spectrum with more than 8000 channels providing an unprecedented accuracy of vertical resolution of temperature and humidity profiles. The IASI instrument has been developed by the French Space Agency CNES, and is the most innovative instrument on MetOp.
The paper will also dwell on the importance of the de-centralised applications ground segment which consists of a central facility and so-called Satellite Application Facilities (SAFs) hosted by EUMETSAT member states primarily at national weather services. The SAF network provides the basis for coordinated and well-planned utilisation of the MetOp data in operations and for a broad and competent user feedback during the early stages of the MetOp life time. Finally the paper will present first results from MetOp-A measurements.