中国沿海地基GPS水汽反演精度分析

利用无线电探空和地基水汽辐射计的观测数据，对中国沿海GPS观测网9个观测站反演的1 h间隔可降水量进行对比分析。与无线电探空结果相比，地基GPS反演可降水量的年相关系数在0.95以上，平均偏差自北向南呈逐渐增大的趋势。除西沙站外，其他站的年平均偏差在2 mm之内，均方差在3 mm之内，且平均偏差和均方差存在季节性变化。与地基水汽辐射计结果相比，地基GPS反演可降水量同样具有很好的正相关，同步观测期间两者相关系数为0.989，两者的平均偏差为1.84 mm，偏差的均方差为2.06 mm，且7～9月的月均方差较大。

Accuracy Analysis on Precipitable Water Vapor Derived from Chinese Coastal GPS Measurement

Comparative analyses is made to the precipitable water vapor (PWV) with hourly intervals derived from 9 GPS stations of the Chinese coastal GPS network, using the observation data from radiosonde, ground-based water vapor radiometer (WVR). The results show the annual correlation coefficient of precipitable water vapor between ground-based GPS and radiosonde is above 0.95 and the mean bias gradually increases from north to south. The annual average deviation of the GPS stations (Xisha is excluded) is less than 2 mm and RMSE is less than 3 mm with evitable seasonal change. Compared with ground-based water vapor radiometer, the correlation coefficient reaches an even better value of 0.989. During the synchronous observation period, their mean deviation is 1.84 mm and the RMSE is 2.06 mm with maximum values occurring in July, August and September.