1. School of Computer and Information Engineering, Henan University, Kaifeng 475004, China
2. Henan Province Engineering Research Center of Spatial Information Processing, Kaifeng 475004, China
3. Henan Key Laboratory of Big Data Analysis and Processing, Kaifeng 475004, China
4. The Second Surveying and Mapping Institute of Hunan Province, Changsha 430103, China
5. Key Laboratory of Natural Resources Monitoring and Supervision in Southern Hilly Region, Ministry of Natural Resources, Changsha 430103, China