中文摘要：

采用南京区域GPS观测网的观测数据,结合地表大气参数,计算出夏季降雨过程中的相对GPS大气可降水量;再加入国内3个IGS参考站的观测数据组成超长基线,计算出同时间段内的绝对GPS大气可降水量,并与探空数据所得的大气可降水量进行对比.结果表明：GPS大气可降水量与探空数据所得的大气可降水量有较强的一致性;在精确性和相关性方面,绝对GPS大气可降水量优于相对GPS大气可降水量;绝对GPS大气可降水量的变化能直观地反映地表实际降水量.

英文摘要：

The relative GPS precipitable water vapor （PWV） during summer rainfall was estimated using the observation data of Nanjing regional GPS network and surface meteorological sensors. The absolute GPS PWV at the same time was calculated using the observation data of Nanjing regional GPS network and three IGS reference stations. Comparison of the absolute GPS PWV and PWV estimated from radiosondes data shows that there is a good agreement between them, the accuracy and correlativity of absolute GPS PWV are better than those of the relative GPS PWV, and the variation of absolute GPS PWV can directly reflect the changes of surface rainfall.