Earth Rotation Parameter Estimation from GNSS and Its Impact on Aircraft Orbit Determination

摘要

Earth rotation parameters (ERP) play a key role in connecting the International Celestial Reference Frame (ICRF) and the International Terrestrial Reference Frame (ITRF). Furthermore, high precision orbit determination and positioning need the precise ERPs, while ERPs are closely related the geophysical fliud mass redistribution and geodynamics. In this paper, global uniformly distributed 75 IGS stations with more than 60 sites tracking GPS+GLONASS simultaneously are selected to estimate Earth Rotation Parameters. Accuracy and method to improve ERP from only IGS stations in and neighboring China are also analyzed in order to provide the reference for BeiDou ERP estimation. The results show that the precision of Polar motion (PM) estimated from daily GPS and GLONASS observations can be achieve at the precision of 0.066 and 0.157 mas, respectively and the precision of length of day (LOD) can achieve at 0.0283 and 0.0289 ms when compared to IERS C04 solutions, respectively. The precision of PM and LOD from regional stations with daily GPS (GLONASS) observations are better than 0.178 mas (0.365 mas) and 0.0291 ms (0.0360 ms), respectively. The precision of PM and LOD from combined GPS+GLONASS are better than 0.153 mas and 0.0292 ms. In addition, the impact of ERP error on aircraft orbit is furthermore discussed. The impact on the LOD is greater than the PM. The orbital error can respectively reach 1, 1 and 0.1 m in X, Y and Z direction with 0.5 mas error in PM and 0.5 ms error in LOD.