改进CIR算法在BDS长基线模糊度解算中的应用

长基线条件下，测站间空间相关性弱，电离层、对流层延迟经过双差并不能很好地消除，致使CIR方法在长基线条件下解算模糊度成功率较低。本文通过BDS三频组合选择长波长、弱电离层组合改进宽巷组合系数，选取（-1，-5，6）代替传统的宽巷组合（0，-1，1），选择弱电离层几何相位组合（4，-5，2）代替传统的窄巷组合（0，0，1），并通过将多频点的伪距观测值和确定了模糊度的宽巷相位观测值线性组合消除电离层延迟一阶项。通过实测数据分析，本文提出的算法能够有效解算超宽巷、宽巷模糊度，提高模糊度解算成功率。

The application of improved CIR algorithm in solving BDS long baseline ambiguity

Under the condition of long baseline, the ionospheric delay and tropospheric delay cannot eliminate well due to the weak spatial correlation between stations, which cause the success rate of CIR method in solving ambiguity under long baseline condition is low. This paper selects the combination of long wavelength and weak ionosphere to improve the combination coefficient of wide lane, uses the combination (-1, -5, 6) instead of the traditional wide lane combination(0, -1, 1), and the weak ionosphere geometric phase combination (4, -5, 2) instead of the traditional narrow lane combination (0, 0, 1), adopts the linear combination of the multi frequency pseudorange observations and the wide lane phase observations to eliminate the first order term of ionospheric delay. Through the analysis of measured data, the algorithm proposed in this paper can effectively solve the fuzzy degree of ultra-wide lane and wide lane, and improve the success rate of ambiguity resolution.