江西地基GPS遥感大气可降水量变化特征及精度

Variation Characteristic and Accuracy of Precipitable Water Vapor from Ground-Based GPS Remote Sensing in Jiangxi

利用GAMIT软件对2009年6月1日-2010年5月31日江西南昌、赣州站地基GPS数据进行了解算,结合地面温度和气压观测资料,反演了逐时大气可降水量,并讨论了大气可降水量的变化特征、与降水的关系及其探测精度。结果表明,江西大气可降水量变化具有显著的时空分布特征;大气可降水量的变化特征对降水预报有一定的指示意义;GPS观测在反映大气可降水量变化趋势方面有很高的精度,并具有全天候监测水汽的优点。

Based on the GPS data acquired from two meteorological observation stations in Nanchang and Ganzhou from June 2009 to May 2010, the hourly precipitable water vapor （PWV） has been retrieved by using the GPS analysis software named GAMIT and combining the surface temperature and pressure. The variation, accuracy of PWV, and the relationship between precipitation with PWV has also discussed. The results show that PWV has some marked features of temporal--spatial distributions in Jiangxi Province, it is rich in summer and shortage in winter, more in south and less in north. PWV and precipitation does not exist obvious proportional relationship, but higher PWV in the atmosphere is a necessary condition for pre- cipitation, and the variation characteristic of PWV has certain instruction significance on the precipitation forecast. Moreover, through the test, the reliability of PWV retrieved by GPS data has been verified whether it rains or not. So we hold the opinion that GPS observation accurately characterizes the variation of atmospheric PWV and has the merit of gauging PWV full time.