成都地区地基GPS观测网遥感大气可降水量的初步试验

Experiment on Driving Precipitable Water Vapor from Ground-Based GPS Network in Chengdu Plain

利用首个成都地区地基GPS观测网2004年7～9月30s间隔的测量数据，通过Bernese GPS SoftwareV4．2解算出30min间隔的天顶总延迟量，结合自动气象站获得的气象资料计算出30min间隔的GPS遥感的大气可降水量。与根据气象探空站探测资料算出的可降水量进行统计对比，确定出本次GPS遥感可降水量试验的精度为3．09mm，两种可降水量时间序列呈现高度的一致性。同时验证了计算对流层加权平均温度的Bevis经验公式在成都地区的适用性。

The estimates of total zenith delay are available using Bernese GPS Software V4.2 based on GPS data every 30 s from the first measurement experiment of a ground-based GPS network in Chengdu Plain of Southwest China during the period of July to September 2004. Then estimates of 0.5 hourly precipitable water vapor （PWV） derived from global positioning system （GPS） are obtained using meteorological data from automatic weather stations. The comparison of precipitable water vapor derived from GPS and those from radiosonde observations is given at Chengdu station, with RMS （root mean square） differences of 3.09 ram. The consistency of precipitable water vapor derived from GPS to those from radiosonde is very good. It is concluded that Bevis empirical formula for estimating the weighted atmos pheric mean temperature can be applicable in Chengdu areas because the relationship of GPS PWV with Bevis＇ formula between GPS PWV with radiosonde method shows a high correlation. The results of this GPS measurement experiment are helpful both for accumulating the study of precipitable water vapor derived from GPS in Chengdu areas located at the eastern flank of the Tibetan Plateau and for studying spatial-temporal variations of regional atmos pheric water vapor through many disciplines cooperatively.