1. National Engineering Research Center of Geographic Information System, China University of Geosciences, Wuhan 430074, China
2. State Key Laboratory of Geo-Information Engineering, Xi’an 710054, China
3. School of Computer Science, China University of Geosciences, Wuhan 430074, China
4. School of Geography and Information Engineering, China University of Geosciences, Wuhan 430074, China
5. Institute of Geophysical and Geochemical Exploration, China Academy of Geological Sciences, Langfang 065000, China