jgg     2014 34 (3):  137-141    ISSN: 0412-1961  CN: 21-1139/TG RESEARCH ON GLONASS ORBIT SIMULATION BASED ON  RUNGE-KUTTA METHOD 1)State Key Laboratory of Geodesy and Earth’s Dynamics，Wuhan 430077 2)University of Chinese Academy of Sciences，Beijing 100049 Received: 2013-10-13  Revised: null  Online: 2014-05-28 Supporting info