jgg     2009 29 (2):  121-125    ISSN: 0412-1961  CN: 21-1139/TG PRECISE ORBIT DETERMINATION OF LOW EARTH ORBIT SATELLITE AND GPS SATELLITE BASED ON COMBINEDORBIT DETERMINATION STRATEGY Kuang Cuilin 1) ; Liu Jingnan 2) ; and Zhao Qile 2) 1)Department of Survey Engineering and Geomatics, Central South University, Changsha 4100832)GNSS Research Center, Wuhan University, Wuhan 430079 Received: 1900-01-01  Revised: 1900-01-01  Online: null Supporting info null