1. MOE Key Laboratory of Fundamental Physical Quantities Measurement, School of Physics, Huazhong Univ. of Science and Technology, Wuhan 430074, China; State Key Laboratory of Geodesy and Earth’s Dynamics, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 430077, China.
2. Professor, School of Geodesy and Geomatics, Wuhan Univ., Wuhan 430079, China (corresponding author).