青藏高原海拔差异大、地面探空站点稀少且分布不均，导致水汽探测时空分辨率低，而高精度和高时空分辨率的水汽探测资料是提高区域降水预报精准度的前提。地基全球定位系统（ground-based global positioning system, GPS）水汽探测是对探空的有效补充，本文利用青藏高原5个典型GPS和探空站点数据，基于姚宜斌模型分析GPS探测大气可降水量（precipitable water vapor, PWV）的精度及影响因素。结果表明：5个GPS站与临近探空站的探测精度相当，均方根误差在2~3 mm，反演结果可以用于分析代表区域的PWV；基于GPS反演PWV，零时刻探测精度优于十二时的值，冬季的探测精度优于夏季，可能受到地面温度和大气可降水量的影响。未来可以结合探空和GPS资料进行水汽反演，为青藏高原水汽条件和降水预报提供数据支撑。

The large difference in altitude and the scarcity and uneven distribution of surface radiosonde stations on the Qinghai-Tibet Plateau result in low spatial and temporal resolution of water vapor detection. It is the premise to improve accuracy of regional precipitation prediction by using water vapor data with high precision and high spatio-temporal resolution. Water vapor detection by ground-based Global Positioning System (GPS) is an effective supplement to radiosonde. Based on Yao Yibin model, this paper analyzes the accuracy and influencing factors of precipitable water vapor (PWV) detected by GPS using the data of 5 typical GPS and radiosonde stations in the Qinghai-Tibet Plateau. The results show that: the detection accuracy of 5 GPS stations is equivalent to that of nearby radiosonde stations, with root mean square error is 2~3 mm. The inversion results can be used to analyze the PWV of the representative area. Based on GPS inversion of PWV, the detection accuracy at 0000 UTC is better than that at 0000 UTC, and that in winter is better than that in summer, which may be affected by the surface temperature and PWV. In the future, radiosonde and GPS data can be combined to perform water vapor inversion to provide data support for water vapor conditions and precipitation forecasts on the Qinghai-Tibet Plateau.

国家重点研发计划项目（2017YFC0403600）；青海省重点研发与转化计划（2019-SF-146）；清华大学水沙科学与水利水电工程国家重点实验室（SKLHSE-2019-B-03）