Objectives With the development of BeiDou navigation satellite system (BDS), many researchers focus on its high precision application, especially in crustal deformation and earthquake prediction. In order to assess the performance of BDS-2 as Chinese regional navigation satellite system in monitoring active deformation, we used GAMIT/GLOBK software to analyze the positioning time series of global positioning system (GPS) and BDS-2 at 23 stations in the crustal movement observation network of China (CMONOC).
Methods Firstly, we used general Gauss-Markov error model to regard the time series as the combination of white noise and color noise. Secondly, we calculated weighted root mean square (WRMS) of the residues to show the positioning errors under long-lasting observation. Finally, the principal component analysis method was applied to get the main components of commode errors.
Results The data processing results show that the root mean square deviation of BDS-2 daily solutions achieves 5-7 mm in horizontal component and 13 mm in vertical component. Based on the statistics of 22 independent baselines, we demonstrate the relative positioning precision of BDS-2 is 3-4 mm+(1-2)×10-8. Moreover, we find that 3-year continuous observations enable a typical velocity uncertainty of 0.6 mm/a for the plate motion.
Conclusions The accuracy of high-precision positioning of BDS-2 is comparable to that of GPS in the early 1990s. Due to imprecise orbit determination and imperfect constellation geometry, BDS-2 time series in vertical component do not provide sufficient information of seasonal variations in surface loading. The estimation of BDS-2 velocities can be used as a supplement to GPS and improve the monitoring accuracy by up to 20% for the CMONOC stations.