1. Key Laboratory of Network Information System Technology (NIST), Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, People’s Republic of China
2. The Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, People’s Republic of China
3. School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing, People’s Republic of China
4. School of Software Engineering, Shenzhen Institute of Information Technology, Shenzhen, People’s Republic of China
5. Institute of Remote Sensing and GIS, Peking University, Beijing, People’s Republic of China
6. School of Geography Science and Geomatics, Suzhou University of Science and Technology, Suzhou, People’s Republic of China