1. Institute of Remote Sensing and Geographic Information System, Peking University, Beijing, China
2. College of Electrical and Information Engineering, Hunan University, Changsha, China
3. Department of Geomatics Engineering, Changsha University of Science and Technology, Changsha, China
4. School of Remote Sensing and Geomatics Engineering, Nanjing University of Information Science and Technology, Nanjing, China
5. School of Automation, Central South University, Changsha, China