再分析资料计算中国区域对流层延迟精度

The assessment of ZTD calculated from reanalysis over China

针对欧洲中期天气预报中心(ECMWF)提供的ERA-Interim气压分层再分析资料在中国区域对流层延迟解算的适用性问题,该文基于中国大陆构造环境监测网络(CMONOC)约260个GPS基准站,以GPS PPP事后精密处理结果作为参考,给出了相应的精度评估与时空分布特征分析,结果表明:再分析资料在中国区域对流层延迟的平均偏差和均方根误差分别为0.39cm和1.37cm,时空分布上存在明显差异,另外指出了再分析资料时间分辨率不足,难以反映对流层延迟日内变化的问题。为进一步研究对流层空间关系以及垂直变化特征,精化对流层改正模型提供参考。

The accuracy of zenith tropospheric delay（ZTD）derived from the meteorological reanalysis product（ERA-Interim）provided by European Center for Medium-Range Weather Forecasts（ECMWF）with high spatial resolution is evaluated.The ZTDs observed from 260 GPS sites in the Crustal Movement Observation Network of China（CMONOC）are taken as references.The results show that the mean bias and Root Mean Square（RMS）of ZTD are about 0.39 and 1.37 cm,respectively,with significant variations in temporal and spatial distribution.In addition,it is pointed out that the time resolution of reanalysis data is difficult to reflect the diurnal variation of tropospheric delay.The reference for studying the spatial distribution and vertical variation characteristics of tropospheric delay and the correction modeling in China is provided.