1. Institute of Geophysics and Planetary Physics; University of California Los Angeles; Los Angeles California USA
2. Laboratoire de Physique et Chimie de l'Environnement, CNRS; Orleans France
3. Rutherford Appleton Laboratory; Didcot UK
4. European Space Research and Technology Centre; European Space Agency; Noordwijk Netherlands
5. Centre d'Etude Spatiale des Rayonnements; UMR 5187, CNRS, Toulouse France
6. Blackett Laboratory; Imperial College; London UK
7. School of Earth and Space Sciences; Peking University; Beijing China