jgg     2012 32 (1):  84-88    ISSN: 0412-1961  CN: 21-1139/TG COMBINATION MODELS FOR NAVIGATION SATELLITE CLOCK PREDICTION Wang Jigang 1) ;Hu Yonghui 2) ;He Zaimin 2,3) ; Yang Haiyan 2,3) ; and Hou Juan 2,3) 1)Huaihai Institute of Technology, Lianyungang 222001;2)National Time Service Center, Xi’an 710600;3)Graduate University of Chinese Academy of Science, Beijing 100049 Received: 1900-01-01  Revised: 1900-01-01  Online: null Supporting info null