1. Institute of Remote Sensing and Digital Earth, The State Key Laboratory of Remote Sensing Science, CAS Olympic S&T Park No. 20, Da Tun Road, P. O. Box 9718, Beijing 100101, China
2. Chinese Academy of Forestry, Research Institute of Forest Resource Information Techniques, Wanshoushanhou, Beijing 100091, China
3. Chinese Academy of Sciences, Institute of Remote Sensing and Digital Earth, Laboratory of Digital Earth Sciences, No. 9 Dengzhuang South Road, Beijing 100094, China