1. School of Space and Environment; Beihang University; Beijing China
2. Department of Space Science and Application, College of Astronautics; Nanjing University of Aeronautics and Astronautics; Nanjing China
3. Space Science and Applications Group; Los Alamos National Laboratory; Los Alamos New Mexico USA
4. Laboratory for Atmospheric and Space Physics; University of Colorado Boulder; Boulder Colorado USA
5. Department of Aerospace Engineering Sciences; University of Colorado Boulder; Boulder Colorado USA