1. Guangxi Key Laboratory of Spatial Information and Geomatics, the College of Earth Sciences, the College of Geomatics and Geoinformation, and the College of Mechanical and Control Engineering, Guilin University of Technology, Guilin, China
2. School of Surveying and Land Information Engineering, Henan Polytechnic University, Jiaozuo, China
3. Guangxi Key Laboratory of Spatial Information and Geomatics and the College of Geomatics and Geoinformation, Guilin University of Technology, Guilin, China