Abstract:
Precise orbit determination and lander positioning have important scientific meaning in deep-space mission. In this paper,preliminary numerical simulations for a multi-way microwave measurement mode in the Lunar and Mars missions are conducted and analyzed. The measurement model of this tracking mode is derived and its advantages are evaluated. Simulation results show that this model has the potential to improve orbit accuracy,and the position of the lander can also be obtained. The quantitative analysis shows that at the noise level of 1 mm/s,for the Lunar spacecraft,the orbit accuracy can be up to several meters and the positioning accuracy of the lander is expected to reach the decimeter level,considering the coordinate system conversion error,the gravitational field error,the ephemeris error and the transponder error. For the Mars spacecraft,the orbit accuracy can reach tens of meters and the lander positioning accuracy reaches the meter level.