1. College of Geodesy and Geomatics, Shandong University of Science and Technology, 579 Qianwangang Rd., Huangdao District, Qingdao, Shandong Province 266590, P.R. China
2. College of Geodesy and Geomatics, Shandong University of Science and Technology, 579 Qianwangang Rd., Huangdao District, Qingdao, Shandong Province 266590, P.R. China (Corresponding author), e-mail: jinyunguo1@126.com, https://orcid.org/0000-0003-1817-1505
3. School of Geographic Sciences, Xinyang Normal University, 237 Nanhu Rd., Xinyang, Henan Province 464000, P.R. China