1. State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
2. University of Chinese Academy of Sciences, Beijing, China
3. Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing, China
4. Department of Geography, University of Tennessee, Knoxville, TN, USA
5. State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan, China