1. School of Geospatial Engineering and Science, Sun Yat-sen University, Zhuhai, China
2. School of Geospatial Engineering and Science, Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China
3. School of Surveying and Land Information Engineering, Henan Polytechnic University, Jiaozuo, China
4. State Key Laboratory of Remote Sensing Science, The Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, China