单历元多频最优消电离层组合集选取研究

Research on Selecting the Single-Epoch Optimal Set of Multi-Frequency Ionosphere-Free Combination

探讨利用双观测值的3种消电离层组合方式,并列出双频和三频模式下的所有消电离层组合观测值。在此基础上,以定位中误差和整周模糊度中误差作为评价指标,提出最优消电离层组合集的选取方法。计算表明,双频模式下16个独立组合集效果均等价,且在高于0.02m伪距噪声的情况下无法获得单历元双差模糊度固定解;三频模式下2 196个独立组合集效果存在显著差异,最优组合集在不高于0.6m伪距噪声的情况下可获得单历元双差模糊度固定解。并且,所选最优组合集优于TCAR/CIR和矩阵变换法的结果。

Ionosphere-free combination sets are proposed in this paper based on three ionosphere-free combination types.Considering both position and ambiguity-fixed RMSE as evaluation indices,the optimal ionosphere-free combination sets are selected in double and triple frequency modes.Computation and analysis results show that the evaluation index of 16 combination sets are equivalent in the double-frequency model,but could not get the ambiguity-fixed in single epoch due to the pseudo-range noise being more than 0.02 m.In the triple-frequency model,there are significant differences in 2 196 independent combination sets;when the pseudo-range noise is under 0.6m,optimal combination set can get the ambiguity-fixed in single epoch.Moreover,combination set 2-Ⅱ has better performance than both the TCAR/CIR and matrix transformation methods.