Real-time single-frequency precise point positioning (RT-SFPPP) of low-cost has been attracting increasing attention in numerous global navigation satellite system (GNSS) applications. Nowadays, three multi-GNSS RT-SFPPP models are widely applied, i.e. ionosphere-corrected (IC), ionospherefree (IF) and ionosphere-weighted (IW) models. A comprehensive evaluation of the three models using CLK93 products is performed in the aspect of observation residuals, positioning accuracy and convergence. Data sets with quad-system are collected from 16 multi-GNSS experiments (MGEX) stations and are analysed in the simulated kinematic precise point positioning (PPP). Besides, kinematic PPP for a 5-h shipborne data set is also conducted. Experimental results show that the positioning accuracy of IW model using MGEX data is better than that of both IC and IF models. Regarding the kinematic shipborne test, positioning accuracy of IF/IW model is of 0.27/0.26, 0.21/0.26 and 0.49/0.48 m for the N, E and U components, respectively, which is much better than that of IC model. As for average convergence time, IW model shows the best performance, which is at least 25% faster than the IF model. Different from both IF and IW models, the amplification of ionospheric errors has some impact on the positioning performance of the IC model at different frequencies.

中文翻译：

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使用国际GNSS服务实时服务比较三种广泛使用的多GNSS实时单频精确点定位模型

低成本的实时单频精确点定位（RT-SFPPP）在众多全球导航卫星系统（GNSS）应用中引起了越来越多的关注。如今，广泛应用了三种多GNSS RT-SFPPP模型，即电离层校正（IC），无电离层（IF）和电离层加权（IW）模型。在观察残差，定位精度和收敛性方面对使用CLK93产品的三个模型进行了全面评估。从16个多GNSS实验（MGEX）站收集具有四系统的数据集，并在模拟运动学精确点定位（PPP）中进行分析。此外，还针对5小时船载数据集进行了运动学PPP。实验结果表明，使用MGEX数据的IW模型的定位精度优于IC和IF模型。关于运动船载测试，IF / IW模型在N，E和U分量上的定位精度分别为0.27 / 0.26、0.21 / 0.26和0.49 / 0.48 m，这比IC模型要好得多。至于平均收敛时间，IW模型显示出最佳性能，比IF模型至少快25％。与IF和IW模型不同，电离层误差的放大对IC模型在不同频率下的定位性能有一定影响。至于平均收敛时间，IW模型显示出最佳性能，比IF模型至少快25％。与IF和IW模型不同，电离层误差的放大对IC模型在不同频率下的定位性能有一定影响。至于平均收敛时间，IW模型显示出最佳性能，比IF模型至少快25％。与IF和IW模型不同，电离层误差的放大对IC模型在不同频率下的定位性能有一定影响。