1. School of Computer and Information Engineering, Henan Engineering Research Center of Spatial Information Processing, Henan University, Kaifeng, China
2. School of Computer and Information Engineering, Henan Engineering Research Center of Spatial Information Processing, Henan Technology Innovation Center of Spatio-Temporal Big Data, Henan University, Kaifeng, China
3. School of Computer and Information Engineering, Henan University, Kaifeng, China
4. State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China