1. Department of Land Surveying and Geo-Informatics, Research Institute for Land and Space, The Hong Kong Polytechnic University, Hong Kong 999077, China
2. MNR Key Laboratory for Geo-Environmental Monitoring of Great Bay Area, College of Civil and Transportation Engineering, Shenzhen University, Shenzhen 518060, China
3. College of Surveying and Geo-Informatics, Tongji University, Shanghai 200092, China
4. School of Geological Engineering and Geomatics, Chang’an University, Xi’an 710054, China