卫星截止高度角、对流层映射函数和海潮模型对南极GNSS精密定位的影响分析

利用长城站、中山站及周边13个IGS站2018年的观测数据，对比分析不同卫星截止高度角、对流层映射函数和全球海潮模型对GNSS坐标精度的影响。结果表明，截止高度角设为7°时，GNSS坐标解算精度最优，随着截止高度角的增大或减小，精度逐渐降低；采用VMF3模型解算的双差定位精度优于NMF、GMF和VMF1模型，VMF3模型解算的精密单点定位精度与GMF和VMF1模型相当；海潮负荷对GNSS坐标解算的影响与坐标方位有关，高程方向可达cm级，选用不同的海潮模型解算的GNSS坐标差异可忽略不计。

Research on Influence of Satellite Cut-Off Elevation Angle,Tropospheric Mapping Function and Ocean Tide Model on Antarctica GNSS PPP

Based on observation data from the GRW1, ZHON and the surrounding 13 IGS stations in 2018, we compare and analyze the effects of different cut-off elevation angles, mapping function models and global ocean tide models on GNSS coordinate accuracy. The results show that the GNSS coordinate presents the highest accuracy when the cut-off elevation angle is 7°. Along with the increase or decrease of the cut-off elevation angle, the accuracy will decrease gradually. The double difference positioning accuracy calculated by VMF3 model is better than that calculated by the NMF, GMF and VMF1 models, the accuracy of the precise point positioning calculated by VMF3 is equivalent to that of GMF and VMF1 models. The effect of ocean tidal load on GNSS coordinate solution is subjected to the coordinate directions, and can reach the cm level in the elevation direction. The differences of the GNSS coordinates calculated by different ocean tide models can be disregarded.