1. Section 2.3, Geomagnetism GFZ German Research Centre for Geosciences Potsdam Germany
2. State Key Laboratory of Space Weather, National Space Science Center Chinese Academy of Sciences Beijing China
3. College of Electronic and Information Engineer South Central University for Nationalities Wuhan China
4. Korea Astronomy and Space Science Institute Daejeon South Korea
5. Department of Astronomy and Space Science University of Science and Technology Daejeon South Korea
6. College of Earth Sciences University of Chinese Academy of Sciences Beijing China