1Faculty of Geomatics, Lanzhou Jiaotong University, Lanzhou, Gansu 730070, China
2Land Satellites Remote Sensing Application Center, Ministry of Natural Resources, Beijing 100048, China
3National-Local Joint Engineering Research Center of Technologies and Applications for National Geographic State Monitoring, Lanzhou, Gansu 730070, China
4Gansu Provincial Engineering Laboratory for National Geographic State Monitoring, Lanzhou, Gansu 730070, China