1. School of Computer Science, China University of Geosciences, Wuhan, China
2. State Key Laboratory of Geo-Information Engineering and Key Laboratory of Surveying and Mapping Science and Geospatial Information Technology of MNR, CASM, China
3. Key Laboratory of Data Protection and Intelligent Management (Sichuan University), Ministry of Education, China
4. College of Engineering, Mathematics and Physical Sciences, University of Exeter, U.K.
5. Department of Information Systems and Cyber Security, University of Texas at San Antonio, USA