1. Page 1 ENVISAT Validation Review – Frascati – 9-13 December 2002 1 st Envisat Validation Workshop MERIS, December 2002 Conclusions and Recommendations

2. Page 2 ENVISAT Validation Review – Frascati – 9-13 December 2002 Plan F Introduction F Calibration u In-flight u Vicarious F Verification F Validation u Cloud and Water Vapour u Land Products Water Products F Conclusion

3. Page 3 ENVISAT Validation Review – Frascati – 9-13 December 2002 Introduction Instrument works very well. In-flight radiometric and spectral calibration performed regularly. Spectral calibration campaigns took place giving an in-flight spectral characterization results with unprecedented accuracy. Verification activity was more demanding than originally expected but produced good results. Following the verification phase, the vicarious calibration and the validation activities started. First results have been presented during the workshop.

4. Page 4 ENVISAT Validation Review – Frascati – 9-13 December 2002 Calibration Team Conclusions Second spectral campaigns confirm early results. - Overall accuracy 0.2 nm, resolution 0.05 nm Radiometric calibration results showed only a little degradation in some of the cameras since launch (below 2.5%) Vicarious calibration results (based on field measurements) showed good agreement (within the accuracy of the method used). Inter comparison with AATSR showed good agreements. Inter comparison results over desert sites showed an over estimation of Meris compared to last century’s sensors.

5. Page 5 ENVISAT Validation Review – Frascati – 9-13 December 2002 Calibration Team Recommendations Spectral characterization Repeat spectral characterization campaigns every six months Improve the instrument model using calibrated data Instrument Degradation: Include a pixel-wise degradation model in the L1b processing Run a diffuser ageing calibration in SciLo configuration (planned) BRDF modelling Improve the BRDF model based on in-flight data Develop a diffuser degradation model Study the Speckle effect Run a vigneting check for diffuser illumination extremes (planned)

6. Page 6 ENVISAT Validation Review – Frascati – 9-13 December 2002 Radiative Transfer Codes Inter-compare the Radiative Transfer Codes used for Vicarious Calibration Tool Box Improvements Include a L1b conversion to TOA reflectance & TOA normalized radiance Include the RTC in the Toolbox for vicarious calibration exercises METRIC Improvements Include Snow, Buoys, instrumented site extraction Include IOCCG Diagnostic data sites extraction Calibration Plan Systematic acquisition of data over designated targets and distribution via FTP Hold Regular Cal/Val workshops Calibration Team Recommendations

7. Page 7 ENVISAT Validation Review – Frascati – 9-13 December 2002 Exploitation of available spectral campaign data SeaWiFs, Chris/Proba Programming of new spectral campaigns for radiometric calibration Spot/Vegetation, ATM, MODIS, GLI, AATSR Calibration Plan Systematic comparison of MERIS and AATSR based on macro-pixels Systematic acquisition of data over designated targets and distribution via FTP Hold Regular Cal/Val workshops Calibration Team Recommendations

8. Page 8 ENVISAT Validation Review – Frascati – 9-13 December 2002 MERIS instrument is in very good shape and performs beyond spec. The validation has started, however,more match up data are needed to conclude on the achieved accuracy. More time is needed to look at the data and make a complete synthesis. The first results look very promising (as per December 2002). The products are now being distributed following smile correction update. MERIS Image Data can be viewed through the Envisat homepage http://envisat.esa.inthttp://envisat.esa.int and through the Multimedia Gallery from ESA’s homepage: www.esa.intwww.esa.int Conclusion