中文摘要：

融合BDS/GPS/GLONASS三系统,采用载波相位平滑伪距观测值和球谐函数建立电离层延迟改正模型,并进行全球电离层反演实验。结果表明,电离层延迟格网值与IGS各分析中心最终产品对比,精度均在4TECu以内,均值为0.675TECu。与基准站GNSS实测TEC比较,差值的均值在5TECu以内。对计算得到的频间偏差月综合产品进行外符合精度和稳定性分析表明,GPS精度优于GLONASS,而BDS稳定性较差。

英文摘要：

The model of ionospheric delay correction is established by fusing BDS,GPS and GLONASS with observations of pseudo distance smoothed by carrier phase and spherical harmonics.Some experiments of inversion of the global ionosphere have been done.The fusion of the three systems not only increases the number of satellites in observation,but also improves the geometric distribution of the puncture point.We fused the variation process of ionospheric daily in October,2013 to obtain the monthly comprehensive differential code bias product and analyzed the accuracy of the products.The analysis result shows that：the ionospheric grid differs from product of IAACs within 4TECu,mean 0.675 TECu.Furthermore,compared with the measured TEC by GNSS from reference station,the mean of the difference is less than 5TECu.In addition,the outside precision and stability analysis of the monthly comprehensive differential code bias product indicates that the precision of GPS is better than GLONASS,while the stability of BDS is poor.