jgg     2010 30 (2):  104-108    ISSN: 0412-1961  CN: 21-1139/TG RESEARCH ON XPL ALGORITHM OF GALILEO INTEGRITY SYSYTEM Gu Shouzhou 1,2) ; Bei Jinzhong 1,3) ; and Dang Yamin 1,2) 1)Chinese Academic of Surveying and Mapping,Beijing 1000392)Shandong University of Science and Technology, Qingdao 2665103)Wuhan University, Wuhan 430079 Received: 1900-01-01  Revised: 1900-01-01  Online: null Supporting info null