Abstract We conduct PPP experiments using 80 global MGEX stations in September 2021, and compare the results with ZTD product released by the international GNSS service (IGS) as a reference. The results reveal significant advantages in ZTD accuracy of multi-system joint estimation. The average RMSE accuracy of GPS+BDS dual-system is approximately 0.6 mm higher than that of single GPS system, while the GPS+BDS+GLONASS+Galileo four-system exhibits a further improvement of about 0.9 mm than dual-system. The ZTD estimation accuracy of GPS under single-system condition is higher than that of BDS. In terms of spatial distribution, the improvement of ZTD estimation accuracy is more significant with increasing latitude. The four-system PPP ZTD accuracy is better than 5 mm when latitude exceeds 50°. Moreover, elevation increase of observation stations can improve ZTD estimation accuracy while latitude remains unchanged. The ZTD estimation accuracy is significantly improved under ambiguity resolution. The average absolute error (MAE) and root mean square error (RMSE) of ZTD estimated by single GPS system are 7.6 mm and 8.4 mm, respectively, which are about 11% and 12% higher than floating-point solutions. The average convergence time is reduced by 20 minutes.
ZHANG Zhichao,WANG Le,LIU Guolin et al. Accuracy Evaluation and Analysis of Spatiotemporal Sequence of Zenith Tropospheric Delay in Multi-System PPP[J]. jgg, 2024, 44(7): 698-703.
ZHANG Zhichao,WANG Le,LIU Guolin et al. Accuracy Evaluation and Analysis of Spatiotemporal Sequence of Zenith Tropospheric Delay in Multi-System PPP[J]. jgg, 2024, 44(7): 698-703.