Tianyu Yu, Wenjian Ni, State Key Laboratory of Remote Sensing Science, Aerospace Information Research Institute, Chinese Academy of Sciences, China; Jie Wang, Aerospace Information Research Institute, Chinese Academy Of Sciences, China; Zhiyu Zhang, Zhifeng Guo, Aerospace Information Research Institute, Chinese Academy of Sciences, China; Guoqing Sun, Department of Geographical Sciences, University of Maryland, College Park, MD 20742, USA, United States