1. Institute of Geodesy and Geoinformation, University of Bonn, Bonn, Germany
2. School of Resource and Environment Sciences, Wuhan University, Wuhan, People’s Republic of China
3. Department of Computer Science and Technology, Nanjing University, Nanjing, People’s Republic of China
4. Wanke School of Public Health, Tsinghua University, Beijing, People’s Republic of China