基于RTKLIB精密单点定位的时频应用研究

Research on Time and Frequency Application Based on RTKLIB Precision Point Positioning

溯源比对装置具备基于导航卫星系统的远程时间溯源功能,将其部署于两地能够溯源至主站实验室展开时差的共视比对,从而构建起时频溯源比对体系,实现两地的高精度时间同步。溯源比对装置接收卫星信号并进行伪距测算时,受到电离层延迟等因素干扰,不利于溯源比对装置进行定位。为提升溯源比对能力,降低共视比对不确定度,需探究单站定时稳定度与定位精度间的相关性。对北京无线电计量测试研究所(BIRMM)连续三个月的共视文件进行解算,可得单站定时稳定度在0.6~1.6 ns范围波动;采用精密单点定位算法解算导航定位文件及精密星历,可得东北天方向定位精度。定位精度与单站定时稳定度曲线波动趋势呈现一致性,利用线性回归分析得到定位精度可解释5.7%的单站定时稳定度变化,表明二者具有弱相关性,即提升单点定位精度对降低共视比对不确定度具有正向影响。

The traceability comparison device has the function of remote time traceability which is based on satellite navigation system.The device that deployed in two places can trace back to the master laboratory to carry out the clock common view comparison,which helps the construction of the time-frequency traceability comparison system,which realizes high-precision time synchronization between two places.When the traceability comparison device receives satellites'signals to calculate pseudo range,it is affected by ionospheric delay and other factors,which is not conductive to the positioning.To improve the capacity of traceability comparison and decrease the uncertainty of common view comparison,it is essential to explore the correlation between timing stability of single station and positioning accuracy.According to the calculation of the common view files of the Beijing Institute of Radio Metrology and Measurement(BIRMM)for three consecutive months,it can be obtained that the timing of a single station is stable in the range of 0.6~1.6 ns.Precision point positioning algorithm is used to calculate the navigation files and the precision ephemeris,and the positioning accuracy of East-North-Up directions can be obtained.The positioning accuracy is consistent with the fluctuation trend of the timing stability curve of single station.Linear regression analysis was used to explain 5.7%of the change in timing stability of single station,indicating a weak correlation between the two sites,which means improving the positioning accuracy of a single point has a positive impact on reducing the uncertainty of the common view.