1. State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, China
2. State Key Laboratory of Geodesy and Earth’s Geodynamics, Chinese Academy of Sciences, Wuhan 430077, China
3. School of Earth and Ocean Sciences, Cardiff University, Cardiff CF10 3AT, UK
4. Institute of Physics and Meteorology (IPM), University of Hohenheim, Stuttgart 70593, Germany
5. School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK
6. Division of Geodetic Science, School of Earth Sciences, Ohio State University, Columbus, OH 43210-1308, USA