1. Graduate School of Communication Engineering and InformaticsUniversity of Electro‐Communications Chofu Japan
2. Institute for Space‐Earth Environmental ResearchNagoya University Nagoya Japan
3. National Institute of Polar Research Tachikawa Japan
4. Ionosphere Research UnitUniversity of Oulu Oulu Finland
5. Graduate School of Natural Science and TechnologyKanazawa University Kanazawa Japan
6. Institute of Space and Astronautical ScienceJapan Aerospace Exploration Agency Chofu Japan
7. Polar Geophysical Institute Murmansk Russia