BDS-3/Galileo四频精密单点定位模型及性能分析

Quad-frequency precise point positioning model and performance analysis for BDS-3/Galileo

北斗三号系统(BDS-3)与欧盟伽利略系统(Galileo)都能提供四频及以上的卫星信号。为充分利用多频信号数据,提高定位精度和可靠性,建立了BDS-3/Galileo四频精密单点定位模型并进行了性能分析。首先在传统双频模型基础上推导了两个四频无电离层组合模型(QF1和QF2)和一个四频非差非组合模型(QF3),并给出了各模型组合系数、电离层和噪声放大系数等参数。其次分析了各模型参数对定位性能的影响。最后通过静态和仿动态PPP实验评估了各模型的定位性能,实验结果表明:提出的四频模型QF1、QF2、QF3静态PPP收敛时间相较于双频模型IF12缩短了约50%、57%、25%,收敛后定位精度分别提升约44%、44%、41%;动态PPP实验中,QF1、QF2、QF3模型所用收敛时间较IF12模型分别缩短约26%、26%、3%,收敛后定位精度分别提升约23%、22%、13%。QF1和QF2模型性能相当,优于QF3模型。

Both the BDS-3 and Galileo can offer four frequencies or more satellite signals.To maximize the use of these signals and enhance positioning accuracy and reliability,a quad-frequency precise point positioning(PPP)model for BDS-3/Galileo is established and its performance is analyzed.Firstly,two quadfrequency ionospheric-free combination models(QF1 and QF2)and uncombined model(QF3)are derived on the basis of the traditional dual-frequency model,and the combination coefficients,ionospheric and noise amplification coefficients of each model are given.Secondly,the influence of each model parameters on the positioning performance is analyzed.Finally,the positioning performance of each model is evaluated through static and simulated dynamic PPP experiments.The experimental results show that the static PPP convergence time of the proposed four-frequency models QF1,QF2 and QF3 is shortened by about 50%,57%and 25%compared with the IF12 model,and the positioning accuracy after convergence is improved by about 44%,44%and 41%.In the kinematic PPP experiments,the convergence time of QF1,QF2 and QF3 models is shortened by about 26%,26%and 3%compared with the IF12 model,and the positioning accuracy after convergence is improved by about 23%,22%and 13%.The QF1 and QF2 models have comparable performance and are superior to the QF3 model.