1. National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing 100190, China
2. Beijing Key Laboratory of Space Environment Exploration, Beijing 100190, China
3. School of Astronomy and Space Science, University of Chinese Academy of Sciences, Beijing 100049, China
4. Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), NSSC/CAS and University of Graz, Beijing 100190, China
5. School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China