1. a Institute of Remote Sensing Applications, Chinese Academy of Sciences , Beijing, 100101, China
2. b Key Laboratory of Digital Earth Science, Center for Earth Observation and Digital Earth, Chinese Academy of Sciences , Beijing, 100190, China
3. c International Institute for Earth System Science, Nanjing University , Nanjing, 210093, China
4. d China Aero Geophysical Survey and Remote Sensing Center for Land and Resources , Beijing, 100083, China