The Use of Laser Altimetry in the Orbit Determination of Chang’E-1

Abstract:

Accurate altimetric measurements can improve the quality of the orbit reconstruction with altimetry data in the form of crossovers. Altimetry from the Chang’E-1 (CE-1) laser altimeter (LAM) has been analyzed in this paper. At first, the combined use of altimetry and Earth-based range measurements has been examined in a simulation study. The differences between crossover constraint in the form of height discrepancies and in the form of minimum distance are mainly discussed. It is found that both crossover constraints can improve the performance of orbit determination. However, crossover constraint in the form of minimum distance between two curves can not only improve the radial component of the satellite orbit but also the cross-track and along-track component. And also, the weighting factor of crossover is discussed in the simulation study. And then, the same method is applied into analysis of altimetry from LAM. It is shown that including laser altimeter data improves the orbit precision.