1. Faculty of Geomatics, Lanzhou Jiaotong University, Lanzhou 730070, China
2. Key Laboratory of Remote Sensing and Digital Earth, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100101, China
3. National-Local Joint Engineering Research Center of Technologies and Applications for National Geographic State Monitoring, Lanzhou 730070, China
4. Key Laboratory of Science and Technology in Surveying & Mapping, Gansu Province, Lanzhou 730070, China
5. The Center of Agriculture Information of Chongqing, Chongqing 401121, China