1. School of Geography and Ocean Science, Nanjing University, Nanjing, China
2. Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, Nanjing University, Nanjing, China
3. Key Laboratory for Satellite Mapping Technology and Applications of State Administration of Surveying, Mapping and Geoinformation of China, Nanjing University, Nanjing, China
4. Collaborative Innovation Centre of Novel Software Technology and Industrialization, Nanjing, China
5. University Corporation for Polar Research, Beijing, China
6. Department of Geological Sciences, University of Texas at San Antonio, Texas, USA
7. Department of Geography, Geology and Planning, Missouri State University, Springfield, MO, USA