Overview of the orbit determination for CE-2 extended mission (IEEE CGNCC)

Chang´E-2(CE-2) extended mission started from June 2011, the maximum distance between CE-2 and the Earth is about 1,700,000 km. In this paper, orbit determination for CE-2 extended mission is discussed, and the orbit accuracy during transfer orbit phase is assessed. The results show that under current tracking condition, the orbit accuracy during the early escape orbit phase is at the level of 1km. As the distance increases, longer arc-length is needed for orbit determination. During the later transfer orbit phase, orbit determination was performed using more than 20-day tracking data, and the orbit accuracy is better than 2km.