Orbit Determination Of The First Chinese Lunar Exploration Spacecraft CE-1

The tracking of the first Chinese lunar exploration spacecraft CE-1 will be performed with a national USB (unified S-band) network and a national VLBI (Very Long Baseline Interferometry) network. This dissertation studied the orbit determination of the lunar exploration spacecraft, emphasizing on the VLBI data and its contribution to the orbit determination. In summary, the main contents are as following:1. The Right Ascension and Declination of the satellite can be computed using VLBI data, and this is the problem of point positioning. The precision of CE-1 angle calculation using national VLBI network was analyzed, using a simple Earth rotation model. The results show the accuracy of CE-1 angel calcultation is affected by the elvation of station, the distantce of statellite and the prior orbit.2. Following the previous simulation work, we used real observation data to study the orbit determination problems using USB and VLBI data. Following an experiment in July, 2004 to test the VLBI network, an experiment of combined tracking and orbit determination of TC-1 satellite was successfully coordinated between the two networks from March 17 to 20, 2005. One goal of this experiment was to validate VLBI's contribution to the on-going CE-1 mission. Combined orbite determination accuracy using USB and VLBI data was studied. Combined orbits were compared with USB-only orbits. For 1day arc, the results...