1. State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing (LIESMARS), Wuhan University, Wuhan 430079, China
2. School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, China
3. Civil Engineering Department, Faculty of Engineering, Minia University, Minia 61111, Egypt
4. Wuhan Gravitation and Solid Earth Tides National Observation and Research Station, Wuhan 430071, China