1. Beijing University of Technology, College of Applied Sciences, Beijing, ChinabChinese Academy of Sciences, Academy of Opto-electronics, Beijing, China
2. Beijing University of Technology, College of Applied Sciences, Beijing, China
3. Chinese Academy of Sciences, Academy of Opto-electronics, Beijing, ChinacInformation Engineering University, Institute of Geospatial Information, Zhengzhou, China
4. Chinese Academy of Sciences, Academy of Opto-electronics, Beijing, ChinadUniversity of Chinese Academy of Sciences, Beijing, China