1. School of Computer Science, China University of Geosciences, Wuhan, People's Republic of China
2. Institute of Remote Sensing and Geographical Information Systems, Peking University, Beijing, People's Republic of China
3. Beijing Key Lab of Spatial Information Integration & Its Applications, Peking University, Beijing, People's Republic of China
4. Information Center, Hubei Geological Environment Station, Wuhan, People's Republic of China
5. College of Geoscience and Surveying Engineering, China University of Mining & Technology, Beijing, People's Republic of China