High Precision Determining and Predicting of Earth Orientation Parameters for Supporting Spacecraft Navigation

Abstract

Earth Orientation Parameters (EOP) are essential for spacecraft navigation missions, such as deep space navigation and GNSS navigation mission, directly affecting navigation accuracy of spacecraft. First, this paper introduces the theories of EOP determination based on VLBI and EOP prediction in Beijing Aerospace Control Center (BACC), with some new data processing methods and strategies. The systems of EOP determination and prediction in BACC, consisting of VieVS and EOPS software (EOPS), could provide daily products of EOP determination and prediction. Then, The EOP determination products in BACC are compared with the products of International Earth Rotation and Reference Systems Service (IERS) and International GNSS Service (IGS). The EOP prediction products in BACC are compared with the products of IERS, United States Naval Observatory, (USNO) and EOP_PCC. The determination standard deviation of Earth polar motion x-component (PMX) is lower than 0.2 mas, Earth polar motion y-component (PMY) is lower than 0.3 mas, UT1-UTC is lower than 0.02 ms, and the determination accuracy is at the same level of the products of IERS and IGS. Meanwhile, the short-term prediction error of PMX/PMY/UT1-UTC is a little lower than EOP_PCC, and is at the same level of IERS and USNO. These compared results show that EOP products in BACC with high precision could effectively meet the requirement of spacecraft navigation mission. Finally, EOP prediction products in BACC were successfully applied on China’s first reentry return flight test mission to support spacecraft’s navigation.