1. National Engineering Research Center of Geographic Information System
2. China
3. Wuhan 430074
4. National Engineering Research Center of Geographic Information System, Wuhan 430074, China
5. Wuhan Geomatics Institute, Wuhan 430074, China
6. Unknown
7. China University of Geosciences
8. Wuhan Zondy Cyber Science & Technology Co., Ltd., Wuhan, China