*Kao Huan Chin¹, Chung-Yen Kuo ¹, Ting-Yi Yang², C.K. Shum^2,3, Yu chan Yi² (1.Department of Geomatics, National Cheng Kung University, Tainan, Taiwan, 2.Division of Geodetic Science, School of Earth Sciences, Ohio State University, Columbus, USA, 3.State Key Laboratory of Geodesy & Earth's Dynamics, Institute of Geodesy and Geophysics, CAS, Wuhan, China)