Qi Wang, Lingling Ma, Ning Wang, Aerospace Information Research Institute,Chinese Academy of Sciences, China; Dongliang Wang, Key Laboratory of Land Surface Pattern and Simulation, Institute of Sciences and Natural Resources Research, Chinese Academy of Science, China; Qian Guo, Yuhang Wang, Geer Teng, Xiaohua Zhu, Aerospace Information Research Institute,Chinese Academy of Sciences, China; Yongxia Zhang, College of Science, North China University of Technology, China