On May 17th, invited by IGG, the vice director of State Department Office of Space and Advanced Technology David A. Turner with his two colleges visted IGG. The director of IGG Sun HP, vice director Yong Wang, Academician Houtse Hsu and the director of SKLGED Sidao Ni etc. participated in the bilateral meeting.

Director Sun expressed warmly welcome to the vistors from American and introduced the basic information, research orientation, recently emphasis and the cooperation with American university and institute. After that, David A. Turner introduced the basice information and main function of State Department Office of Space and Advanced Technology and the purpose of this visiting.

On the meeting, Sidao Ni presented the research contents of his research group on the mantle coupling, earth rotation magnetic variation using Geodesy and Seismic technology and the application result of mantle boundary research using high frequency GPS. Researcher Wang H introduced the glacier isostatic adjustment theory, the result of isolating ancient ice cap area hydrology in north American and north Europe using GRACE and GPS. Researcher Yunbin Yuan introduced the research result of ionospheric delay correction and precise satellite orbit determination and positioning, presented the ionosphere delay correction model and the dynamic data process platform of GPS/BDS.

During the meeting, David A. Turner answered the question about the data openness of Americian gravity satellite. Both sides discussed about the precise GNSS positioning, crustal movement monitor and seimic research and possible cooperation in the future.