1. School of Computer and Information Engineering, Jiangxi Normal University, Nanchang, China
2. State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan, China
3. School of Geography and Environment, Jiangxi Normal University, Nanchang, China
4. School of Information Science and Technology, Southwest Jiaotong University, Chengdu, China