[1] Institute of Geodesy and Geophysics, Chinese Academy of Sciences, 340 Xudong Road, Wuhan 430077, China
[2] Department of Mathematical and Physical Science, Wuhan University of Science and Engineering, 1 Fangzhi Road, Wuhan 430073, China
[3] Graduate School of the Chinese Academy of Sciences, A 19 Yuquan Road, Beijing 100039, China