1. Centre d'Etude Spatiale des Rayonnements; Centre National de la Recherche Scientifique; Toulouse France
2. Institute of Geophysics and Planetary Physics; University of California; Los Angeles California USA
3. Department of Physics; University of California; Los Angeles California USA
4. Geospace Research Center, Solar-Terrestrial Environment Laboratory; Nagoya University; Nagoya, Aichi Japan
5. Space Sciences Laboratory; University of California; Berkeley California USA
6. Laboratoire de Physique et Chimie de l'Environnement; Centre National de la Recherche Scientifique; Orleans France
7. Space Science Department, European Space Research and Technology Centre; European Space Agency; Noordwijk Netherlands