|
|
|
 |
|
MSG (Meteosat Second Generation) is the follow-up system to the old meteosat series. There will be four MSG satellites covering the 2002-2018 period. MSG1 was launched in 2002, MSG2 in 2005. MSG satellite carries the SEVIRI (Spinning Enhanced Visible and InfraRed Imager) radiometer which is greatly improved compared to first generation meteosat. Those improvements include better spatial resolution, 3 km sampling distance and 1 km for the High Resolution Visible (HRV) channel, shorter repeat cycle of 15 mn, better radiometric performances and improved data encoding facilities and 12 channels from the visible to thermal infrared. Detailed informations about MSG system could be found at Eumetsat. Meteorological forecasting remains the first mission of SEVIRI but enhanced caracteristics of SEVIRI sensors allow many other application fields, including aerosols and clouds observation in the frame of climate studies. ICARE is interested by that last field and an aerosol inversion algorithm over oceans developed by Thieuleux et al. in the frame of the ESA/Eumetsat MSG Research Annoucement of Opportunity (MSG-RAO) has been operationnally implemented. SEVIRI L15 data are received in near real time from a EumetCAST system set up at LOA, archived at ICARE and then processed to deliver aerosol standard products (optical thickness and angstrom coefficient) in HDF format. In order to navigate easiliy among those data a SEVIRI browser is available.
The AEROSEVIRI project purpose is to provide the scientific community with an estimate of optical thickness of aerosols over sea (roughly speaking, a measure of their opacity), as well as their Angstrom coefficient (related to the particle size distribution), retrieved from SEVIRI on MSG (Meteosat Second Generation) measures. The scientific algorithm and its implementation must be credited to François Thieuleux et al. [1]. The principle of the algorithm and its implementation details are thoroughly described in [2] (only in french for the time being), so we won't discuss them further here.
ICARE implemented support for the new XRIT format which is now used by
EUMETSAT for MSG direct broadcast (the original code accepted
older NATIVE and OpenMTP formats), and integration to an automated running
environment, while producing raw products [3] (degraded or not at the user's will), temporal averages and
browses for quick-viewing on the web. AEROSEVIRI's User's Guide is avalaible here. [1] F. Thieuleux, C. Moulin, F. M. Bréon, F. Maignan, J. Poitou and D. Tanré : Remote Sensing of Aerosols over the oceans using MSG/SEVIRI Imagery accepted, Int. J. Rem. Sens. [2] F. Thieuleux : Code de traitement des mesures plein résolution Meteosat - Inversion des paramètres optiques des aérosols sur mer - Manuel utilisateur
[3] These raw products are publicly downloadable on the Icare Web Site. These are headerless, binary files,
containing only arrays of 3712x3712 bytes (unsigned 8-bit integers). |
 |
 |
