New Method and Accuracy Analysis for Medium and Long-term Prediction of BDS-3 Orbit

Long-term orbit prediction serves as an effective method to suppress the overall rotation of the inertial frame in autonomous navigation of satellite navigation systems, and the main factor influencing the accuracy of long-term orbit prediction is the uncertainty associated with the solar radiation pressure perturbation model. This paper proposes a method of modeling and updating the ECOM-5 solar radiation pressure model parameters for long-term orbit prediction, and evaluates its performance by fully using the correlation between the solar radiation pressure coefficient and the solar altitude angle. Taking 24 Medium Earth Orbit (MEO) satellites and 2 Inclined Geosynchronous Orbit (IGSO) satellites of the Beidou-3 global navigation satellite system (BDS-3) as an example, 18 groups of 90 days’ orbits were predicted from 2022/01/01 to 2023/06/01. And then the precise ephemeris of Center for Orbit Determination in Europe (CODE) was used as the reference orbit to evaluate the performance of long-term orbit prediction. The experiments results indicate that adopting the new orbit prediction method proposed in this paper for 90 days’ orbit prediction of navigation satellites,  for MEO satellites, the average Root Mean Square (RMS) of the three-dimensional position error on the 30^th day, 60^th day, 90^th day is approximately 200m, 700m, and 1.4km, respectively, and that of the average URE RMS of the orbit is 18.79m, 61.43m, and 124.00m, respectively; The RMS mean values of the orbital inclination angle i are 6.07mas, 9.76mas, and 12.38mas, respectively, and those of the right ascension of the ascending node Ω are 6.47mas, 11.24mas, and 14.88mas, respectively; For IGSO satellites, the three-dimensional position error of the forecast orbit is one order of magnitude lower than that of MEO satellites, while the prediction errors of i and Ω are comparable to those of MEO satellites. Therefore, it can be concluded that the method in this paper exhibits high accuracy in predicting long-term orbital positions and orbital orientation parameters i and Ω, which is expected to provide essential support for mitigating the overall rotation of autonomous navigation of navigation satellite constellations.