1. Jiangsu Provincial Key Laboratory of Geographic Information Technology, School of Geography and Ocean Science, Nanjing University, Nanjing, China
2. Department of Geographic Information Science, Nanjing University, Nanjing, China
3. Collaborative Innovation Center for the South Sea Studies, Nanjing University, Nanjing, China
4. Collaborative Innovation Center of Novel Software Technology and Industrialization, Nanjing University, Nanjing, China