北斗三号三频组合观测值特性分析研究

北斗三号卫星导航系统今年已步入全球组网阶段,预计到2018年底BDS-3的服务区域将覆盖“一带一路”国家及周边国家.目前BDS-3已发布B1I、B1C、B2a和B3I四个信号的用户接口控制文件,本文利用函数极值法给出了特定波长和电离层延迟影响系数下的噪声最优线性组合系数,分析得出BDS-3最优超宽巷组合为三频信号(B1C,B1I,B2a)和(B1C,B1I,B3I)中的线性组合(1,-1,0),最优宽巷组合为三频信号(B1I,B3I,B2a) 和(B1C,B3I,B2a)中的线性组合(1,-3,2),这三个组合也是BDS-3、BDS-2和GPS中的最优组合.利用北斗三号的实测数据进行长短基线下宽巷／超宽巷双差模糊度解算,验证了BDS-3最优宽巷与超宽巷组合的结论的同时,还得出三频信号(B1I,B3I,B2a)和(B1C,B3I,B2a)中的宽巷组合(1,-3,2)与超宽巷组合(1,-4,3)和(0,1,-1)在长／短基线情况下均适用,而筛选得到的较优三频信号(B1C,B1I,B2a)和(B1C,B1I,B3I)中的宽巷／超宽巷组合仅在短基线场景下均适用. 

Research on the Model of BDS-3 Triple-Frequency Carrier-Phase Combination Observations

The BDS-3 satellite navigation system has entered the global coverage stage this year, and it is expected that the service area of the BDS-3 will cover the “the Belt and Road” countries and neighboring countries by the end of 2018. At present, the BDS-3 has released four ICD (Interface Control Document) for the signal B1I, B1C, B2a, and B3I. The optimal linear coefficients with minimal noise are induced with the analytical method considering the wavelength and ionoshperic scale factor of combinations. It is shown that the optimal extra wide lane (EWL) combination of the BDS 3 are the linear combination (1,-1,0) of the signals (B1C,B1I,B2a) and (B1C,B1I,B3I), and the optimal wide-lane (WL) combination is the linear combination (1,-3,2) composed with the signals (B1I,B3I,B2a) and (B1C,B3I,B2a), these three combinations are also the best combination among all the BDS-3, BDS-2 and GPS linear combinations. Using the measured data of BDS-3 to select the WL／EWL combinations for double-difference ambiguity resolution under the long and short baseline, not only the conclusion of the combinations of WL and EWL is verified, it is also concluded that the WL combinations (1,-3,2) and EWL combinations (1,-4,3) and (0,1,-1) of triple frequency signals (B1I,B3I,B2a) and (B1C,B3I,B2a) are applicable to both long and short baseline conditions, and the better WL／EWL combinations of triple-frequency signals (B1C,B1I,B2a) and (B1C,B1I,B3I) are only applicable to the short baseline conditions.