Wenxin Tian, Lingli Tang, Aerospace Information Research Institute, Chinese Academy of Sciences (CAS), China; Yuwei Chen, Finnish Geospatial Research Institute, China; Ziyang Li, Shi Qiu, Haohao Wu, Huijing Zhang, Linsheng Chen, Aerospace Information Research Institute, Chinese Academy of Sciences (CAS), China; Peilun Hu, Changhui Jiang, Jianxin Jia, Haibin Sun, Juha Hyyppä, Finnish Geospatial Research Institute, China