Xiaotong Sun, Hohai University, China; Lina Zhuang, Lianru Gao, Aerospace Information Research Institute, Chinese Academy of Sciences, China; Hongmin Gao, Hohai University, China; Xu Sun, Aerospace Information Research Institute, Chinese Academy of Sciences, China; Yi Liu, Group of Research & Development, Det Norsk Veritas, Norway; Yao Liu, Land Satellite Remote Sensing Application Center, China; Bing Zhang, Aerospace Information Research Institute, Chinese Academy of Sciences, China