极地地区多模GNSS精密单点定位精度分析

基于多模全球导航卫星系统（GNSS）与精密单点定位(PPP)技术，分析极地多模GNSS精密单点定位策略。通过一天一站解和一天多站解，对11种不同导航卫星系统组合下的精密单点定位结果进行实验分析。结果表明：1）各组合中BDS和Galileo组合的定位结果最差，与平均值相比定位精度的差值范围在0.4~1.3 cm之间；2）极地地区各组合N方向收敛时间的平均值为7~11 min，定位精度的平均值优于1.3 cm，明显优于E方向和U方向；3）相同环境下三系统组合较双系统组合在E、N、U方向的收敛时间分别缩短10.3%、14.1%、7.3%，在定位精度上分别提升9.6%、4.6%、11.7%；四系统组合较三系统组合在E、N、U方向的收敛时间分别缩短6.8%、－2.1%、2.0%，在定位精度上分别提升4.9%、－7.1%、5.3%。研究结果表明，三系统组合的定位性能较双系统组合提升明显，四系统组合较三系统组合定位性能改善不明显。

Accuracy Analysis of Polar Multi-GNSS Precise Point Positioning

We analyze the multi-GNSS precise point positioning(PPP) strategy in the polar region based on GNSS and PPP technology. Through one-station solution per day and multi-station solution per day, we analyze the PPP results under 11 different navigation satellite system combinations. We conclude that the positioning results of BDS and Galileo combination is the worst among all the combinations, and the difference in positioning accuracy between the combination and the average value is 0.4-1.3 cm. In the polar region, the mean of convergence time in the N direction of each combination is 7-11 min, and the mean of positioning accuracy is better than 1.3 cm, which is significantly better than that in the E and U directions. In the same condition, the convergence time of the three-system combination in the E, N and U is reduced by 10.3%, 14.1% and 7.3%, respectively, the positioning accuracy is increased by 9.6%, 4.6% and 11.7%, respectively, compared with the two-system combination. Compared with the three-system combination, the convergence time of the four-system is shortened by 6.8%, -2.1% and 2.0%, respectively, and the positioning accuracy is improved by 4.9%, -7.1% and 5.3%, respectively. The results show that the positioning performance of the three-system combination is better than that of the two-system combination, and the positioning performance of the four-system combination is less improved than that of the three-system combination.