1. Chinese Academy of Surveying and Mapping, Beijing 100830, China
2. School of Civil Engineering and Geomatics, Shandong University of Technology, Zibo 255000, China
3. School of Surveying and Geo-Informatics, Shandong Jianzhu University, Jinan 250101, China
4. State Key Laboratory of Geodesy and Earth’s Dynamics, Innovation Academy for Precision Measurement Science and Technology, CAS, Wuhan 430077, China