1. School of Geography and Planning, Sun Yat-sen University, Guangzhou, China
2. Laboratory of Intelligent Collaborative Computing, University of Electronic Science and Technology of China, Chengdu, China
3. China Railway Tunnel Group Company Ltd., Guangzhou, China
4. School of Geospatial Engineering and Science, Sun Yat-sen University, Zhuhai, China
5. Key Laboratory of 3D Information Acquisition and Application, Beijing Advanced Innovation Center for Imaging Theory and Technology, College of Resource Environment and Tourism, Capital Normal University, Beijing, China