1. College of Geomatics and Geoinformation, Guilin University of Technology, Guilin 541004, China
2. Shenzhen Data Management Center of Planning and Natural Resources (Shenzhen Geospatial Information Center), Shenzhen 518040, China
3. Guangxi Key Laboratory of Spatial Information and Geomatics, Guilin University of Technology, Guilin 541004, China