- 1Technology and Engineering Center for Space Utilization, Chinese Academy of Sciences
- 2University of Chinese Academy of Sciences
Due to mission objective constraints, some low Earth orbit satellites are required to operate in flexible attitude modes, but meanwhile stable Precise Orbit Determination (POD) performances must be guaranteed persistently. In this case, a single zenith-mounting antenna, as most missions have done in the past, will not fulfill POD requirements because its GNSS signal tracking might be significantly downgraded in certain attitude modes. A straightforward solution is carrying two antennas for better receiving geometry. This research investigated PODs for different satellites using GNSS observations from two antennas, which were installed with an angle varying between 45 and 180 degrees in the satellite body-fixed reference frame. The preprocessing and screening of GNSS observations was elaborately done to maximize the continuous arc for ambiguity estimation, in particular for cases when the two antennas tracked the same GNSS satellites alternatively or simultaneously. The potential signal delay between the two antennas and the independent phase patterns need to be evaluated. Afterwards the different GNSS observations were robustly merged referring to the satellite’s center-of-mass. Results indicated that the GNSS observation fusion strategy significantly enhanced the stable POD performances for attitude modes where single antenna was impossible to receive sufficient GNSS observations. The overlapping consistency and internal consistency between the reduced-dynamic orbits and the kinematic orbits were only 1-2 cm in the local orbital reference frame, obtaining a similar level as other renown missions with single zenith-mounting antenna. Besides, such dual-antenna GNSS tracking configuration enabled potential assessments of center-of-mass coordinates as well as other applications.
How to cite: Mao, X., Wang, W., and Gao, Y.: Precise orbit determination for satellites in flexible attitude modes using dual-antenna GNSS observations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14826, https://doi.org/10.5194/egusphere-egu25-14826, 2025.