jgg     2012 32 (2):  105-109    ISSN: 0412-1961  CN: 21-1139/TG PERFOMANCE ASSESSMENT OF GPS/GLONASS PRECISE POINT POSITIONING Wang Zhengjun School of Communication and Transportation Engineering, Changsha University of Science and Technology, Changsha 410076 Received: 1900-01-01  Revised: 1900-01-01  Online: null Supporting info null