GPS信号斜路径方向水汽含量的计算方法  

Estimation of Slant Water Vapor Along GPS Ray Paths

作　　者：宋淑丽[1] 朱文耀[1] 程宗颐[1] 廖新浩[1] 

机构地区：[1]中国科学院上海天文台,上海200030

出　　处：《天文学报》2004年第3期338-346,共9页Acta Astronomica Sinica

基　　金：上海科技发展基金(JC14012)资助

摘　　要：利用GPS信号斜路径方向的水汽含量(SWV)探测水汽的三维分布,是目前国际上地基GPS气象学研究的前沿课题.基于此提出了一种利用无电离层影响的GPSLC非差观测组合直接计算斜路径方向水汽含量的方法.该方法每30秒钟计算一次斜路径方向的水汽含量.计算结果与水汽辐射计(WVR)的观测值比较表明,利用该方法计算斜路径方向的水汽含量可以达到毫米级的精度.把5分钟内的斜路径水汽投影到天顶方向取平均,与以5分钟间隔估计的可降水量(PWV)进行比较,结果表明二者之间的差别小于2mm.用该方法计算的GPS信号斜路径方向上的水汽含量,可以用于层析水汽的三维分布,优化数值天气预报的初始场,也可以改正GPS大地测量和雷达影像的误差.Slant water vapor (SWV) measurements along GPS ray paths have the potential to be useful in reconstructing three dimensional water vapor field, which is the key problem of GPS meteorology. A direct method of estimating SWV using GPS non-difference LC observation combinations without the effect of ionosphere is presented. Comparing with Water Vapor Radiometer (WVR) measurements showed that it can get millimeter level accuracy of SWV estimated by this method every 30 seconds. The difference between the averages of SWV in 5 minutes after scaled to zenith and PWV estimated directly by GIPSY very 5 minutes is less than 2mm. SWV obtained by the this method can be used in tomography to sense the three dimensional structure of water vapor and improve the initial conditions of numerical weather forecast. It's also useful in correcting the error of GPS geodesy and radar images.

关 键 词：GPS 斜路径延迟 斜路径水汽含量 信号 

分 类 号：P123[天文地球—天体测量] P228.4[天文地球—天文学]