Earth rotation parameters determination by integrating ground and LEO-spaceborne BDS-3 data

This study investigates the effect of integrating low-earth-orbit (LEO) spaceborne BDS-3 observations on earth rotation parameters (ERP) accuracy across three POD arc lengths including 1 day, 30 h, and 3 days. Using 15–90 global and 15–40 regional stations, results reveal significant ERP accuracy improvements with LEO augmentation. For instance, adding 2 LEO satellites to 15 global stations reduces the root-mean-squares (RMSs) of X_P, Y_P, and LOD differences relative to the international earth rotation and reference systems service (IERS) 20 C04 product to 146.7 μas (31.6% reduction), 101.9 μas (20.7%), and 28.4 μs (5.0%), respectively, in a one-day case. Similarly, with 15 regional stations, these values decrease to 253.0 μas (51.5% reduction), 434.6 μas (32.3%), and 104.9 μs (38.2%), respectively. Notably, in cases with three distinct POD arc lengths, the inclusion of two LEO satellites enables 60 global stations to match the accuracy of 90 global stations, and 25 regional stations to equal 40 regional stations. This finding validates the potential of integrating LEO-spaceborne BDS-3 observations to reduce the dependency of ERP determination on extensive ground networks. Additionally, correlation analysis indicates that the introduction of LEO satellites reduces the correlations among the estimated parameters, which might account for the ERP accuracy improvement contributed by LEO satellites. Overall, incorporating BDS-3 observations from LEO spaceborne receivers mitigates parameter correlation, thereby enhancing ERP estimation.