1. LPC2E/CNRS, University of Orleans; Orleans France
2. Space Research Institute; RAS; Moscow Russia
3. CEA, DAM, DIF; Arpajon France
4. Space Sciences Laboratory; University of California; Berkeley California USA
5. Astronomy and Space Physics Department; National Taras Shevchenko University of Kiev; Kiev Ukraine
6. Office National d'Etudes et de Recherche Aerospatiales; The French Aerospace Laboratory; Toulouse France
7. Centre National d'Etudes Spatiales; Toulouse France