1. National Time Service CenterChinese Academy of SciencesXi'an710600People's Republic of China
2. Key Laboratory of Precision NavigationPositioning and Timing TechnologyChinese Academy of ScienceXi'an710600People's Republic of China
3. University of Chinese Academy of SciencesBeijing100049People's Republic of China
4. Shaanxi Earthquake Agency4 Shuiwen LaneXi'an710068People's Republic of China