GNSS观测站环境变化对数据质量的影响

针对周围有树遮挡的GNSS观测站数据质量检测问题,该文利用TEQC软件分析多期观测资料每个观测时段的多路径效应MP1/MP2、数据有效率及周跳等指标的变化,结合站点实际照片及观测季节等分析变化原因。结果表明:数据质量随周围树的遮挡情况不同而变化。遮挡增强时,数据质量变差;冬季树落叶后,MP1/MP2相应变小,数据有效率提高。而对位于周围植被受季节影响不大地区的测站,各项指标变化也不是很大。采用扼流圈天线可有效减少周跳。建(构)筑物的遮挡对卫星信号接收影响明显,数据有效率低,解算的速度场误差大。环境变差的观测站通过数据后处理,不能完全消除多路径效应和/或周跳的影响。以上结论可为GNSS选建站、观测、数据处理及行业标准的制定等提供参考。

Study on the data quality with the changing surroundings of GNSS stations

The quality checking results of the GNSS stations which are surrounded by trees werestudied in the paper.TEQC software is used for the different observations in several periods.The change of the indicators,such as MP1/P2 for multipath effect,the ratio of overall observations to possible observations,and the ratio of observations to slips are analyzed with the photos taken in the field and observation season.The results show the data quality is mainly influenced by the surrounding high trees.It is more coverage of trees and/or buildings/structures and more quality worse.The value of MP1/MP2 become smaller and more observation data is received when the leaves fall down in winter.Whereas the indicators will not become more worse if the station' s surrounding has little change with the season.The choke ring antenna can effectively reduce cycle slips.The coverage of buildings/structures can reduce the receiving the satellite signal obviously.The possible observations become less and the velocity errors become bigger.The influence from the multipath effect and/or the cycle slips can't be completely eliminated in the data processing if the stations have the worse observation surroundings.The conclusions can help the establishment of GNSS stations,measurements,data processing and formulating standards in future.