1. Geomatics Engineering Department, Sichuan College of Architectural Technology, Deyang 618000, China
2. Tianjin Centre of Geological Survey, China Geological Survey, Tianjin 300170, China
3. Institute of Remote Sensing Satellite, China Academy of Space Technology, Beijing 100094, China
4. Key Laboratory of Digital Earth Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China
5. School of Geography, Development and Environment, The University of Arizona, Tucson, AZ 85719, USA