1. a Key Laboratory of Resources Remote Sensing and Digital Agriculture, MOA , Hulunber Grassland Ecosystem Observation and Research Station , Institute of Agricultural Resources and Regional Planning , Chinese Academy of Agricultural Sciences , Beijing 100081, China
2. b State Key Laboratory of Remote Sensing Science , Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University , Beijing, 100101, China
3. c Graduate School of Chinese Academy of Sciences , Beijing, 100049, China
4. e The Center of Remote Sensing and GIS , Beijing Normal University , Beijing, 100875, China
5. d International Institute for Earth System Science , Nanjing University , Nanjing 210093, China