沿海GPS/GLONASS提取天顶对流层延迟方法研究

Study on the Method of Extracting Zenith Tropospheric Delay by GPS/GLONASS in Coastal Area

基于中国沿海GNSS观测网20个测站31d的数据,从数据处理模式、系统组合和卫星截止高度角等方面研究沿海地区GPS/GLONASS数据提取天顶对流层延迟的方法,以CODE提供的对流层产品和探空数据资料作为标准值来评价对流层延迟的精度。结果表明,截止高度角为10°时,采用双差网解GPS/GLONASS组合系统提取的天顶对流层延迟精度略优于双差网解GPS单系统和精密单点定位GPS/GLONASS组合系统,各方法提取结果不存在明显的系统偏差;截止高度角设置对天顶对流层精度影响较大,截止高度角为30°时,采用双差网解GPS单系统提取的结果精度最优,但其精度较低截止高度角时明显降低。

Based on data collected for 31 days at 20 stations of the Chinese coastal GNSS observation network in 2014,the method of estimating zenith tropospheric delay(ZTD) from GPS/GLONASS data in coastal areas is studied from data processing modes,system combinations and cut-off elevation angle.The ZTD products of CODE and radiosonde data are used as references to assess the estimated ZTD.The study indicates that the ZTD estimated from combined GPS/GLONASS double difference is better than that from GPS double difference and combined GPS/GLONASS precise point positioning(PPP) under 10° cut-off elevation angle.There is no obvious systematic bias in the extraction results of each method.Satellite cut-off angle setting has a great influence on the ZTD accuracy.The ZTD extracted by the double-difference network solution GPS single system has the best accuracy under 30° cut-off elevation angle,but its precision is significantly reduced compared to the results of the lower cut-off angle.