鉴于当前许多IGS跟踪站均配置有高性能原子钟的现状,本文首先采用修正Allan方差法分析了不同IGS跟踪站的接收机钟随机噪声的时域特性,进而评估了不同类型接收机的短期稳定度及钟差建模的可行性,然后利用IGS站配有氢原子钟的观测数据,在精密单点定位算法中,通过对钟差参数进行短时建模约束接收机钟差的随机变化,进而改进精密单点定位(PPP)的定位性能.试验结果表明钟差建模方法显著降低了高程分量参数、天顶对流层延迟参数与接收机钟差参数之间的相关性,GNSS高程分量的精度可提高50%.该方法对于提升PPP技术在地壳形变监测、低轨卫星定轨、水汽监测及预报等高精度GNSS地学领域的应用水平具有一定意义.
Presently, many IGS tracking stations have been equipped with high performance atomic clocks. In this paper, the modified Allan variance method is used to analyze the time-domain characterization of random noise of receiver clocks from different IGS tracking stations. Then, we not only evaluate the short-term stability of different types of receiver clock and the feasibility of clock modeling, but also take advantage of the observational data of Active Hydrogen Maser from IGS station in order to constrain random variation of receiver clock offset by implementing short-term clock modeling in precise point positioning(PPP) algorithm and improve positioning performance of PPP. The experiment results show that the method of clock modeling reduces the correlation between the height component, the zenith path delay and receiver clock offset parameter, the accuracy of height component can be improved by 50%. The proposed method can improve the PPP performance in crustal deformation monitoring, LEO satellite orbit determination, GNSS methodology and many other high precise GNSS geoscience fields when a high-performance atomic clock is deployed.
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