1. Institute of Space Physics and Applied Technology; Peking University; Beijing China
2. Geophysical Institute; University Alaska Fairbanks; Fairbanks Alaska USA
3. Department of Physics Institute for Earth, Oceans and Space; University of New Hampshire; Durham New Hampshire USA
4. The Aerospace Corporation; Los Angeles California USA
5. Space Science Laboratory; University of California; Berkeley California USA
6. School of Physics and Astronomy; University of Minnesota, Twin Cities; Minneapolis Minnesota USA
7. Department of Physics and Astronomy; University of Iowa; Iowa City Iowa USA