测站间高差对短时段GPS基线解算的影响

基于美国CORS网数据，分别选取平均基线长度和站间高差均不相同的6个GPS实验网，使用GAMIT/GLOBK软件，从基线较差、基线重复性、NRMS值以及解算中误差等方面分析站间高差对短时段（4 h）GPS基线解算的影响及削弱这些影响的方法。结果得出，当测站间高差大于100 m时，如果不估计对流层参数，即使是短基线也会使解算基线在高程方向的偏差达到1 cm，而对平面分量影响很小。此时，必须通过估计天顶方向的对流层参数来削弱其影响，才能保证最终解算的基线结果在高程方向的误差小于1 cm。

The Impact of the Height Difference between Stations on the Baselines Solution of Short Period GPS Observations

To analyze its influence, 6 sets of experimental network are selected based on the CORS of America. The averages of the height and distance between the stations in the experimental network aredifferent from each other. By applying GAMIT/GLOBK data processing software, we analyze the impact of the height difference on the baselines solutions from 4 aspects, including comparisons with the true baselines values, baselines repeatability, NRMS and precision. The results show that it will bring about 1 cm error in the ‘up’ component of the baselines solution, if the height difference between stations is more than 100 m. However, the error can be decreased to 1 cm if a tropospheric delay parameter is introduced. In this way we can get a high precision baselines solution.