Analysis of Cislunar DRO Orbit Determination Accuracy Using Earth-Based Simulated Observations

Based on the existing tracking and measuring conditions of China’s deep space exploration missions, the orbit determination accuracy of the DRO probe was simulated and analyzed. For the Cislunar space DRO exploration, the simulation adopted batch processing orbit determination method, selected celestial bodies centered on the Earth for orbit integration, and increased non-spherical gravitational perturbation of the moon. Under the current measurement conditions, the position and velocity accuracy of 2-day short-arc orbit determination using only range tracking data were the order of km and better than 3 cm/s respectively; for 7-day predictions, the maximum differences in the position and velocity are the order of ten kilometers and 6 cm/s respectively. When using ranging data combined with VLBI data, the position and velocity accuracy were the order of hundreds of meters and less than 0.4 cm/s respectively; for 7-day predictions, the maximum differences in the position and velocity were the order of kilometers and 2 cm/s respectively, which shows that VLBI data significantly improved the accuracy of short-arc orbit determination and prediction. Moreover, the position and velocity accuracy were better than 1 km and 1cm/s respectively when using 5-day long-arc range tracking data. For 7-day predictions, the maximum differences in the position and velocity were less than 2 km and 1cm/s respectively. This shows that an increase of ranging data significantly contributes to the accuracy of orbit determination and prediction for DRO.