1. Department of Physics and Astronomy University of Iowa Iowa City Iowa USA
2. Institute for Physical Science and Technology University of Maryland College Park Maryland USA
3. School of Space Research Kyung Hee University Yongin South Korea
4. Institute of Atmospheric Physics ASCR Prague Czech Republic
5. Faculty of Mathematics and Physics Charles University Prague Czech Republic
6. Department of Physics Lancaster University Lancaster UK
7. Mullard Space Science Laboratory University College London Dorking Surrey UK