文档介绍：地基GPS遥感大气水汽含量的误差分析*
陈俊勇
(国家测绘局,北京,100830)
ON THE ERROR ANALYSIS FOR THE REMOTE SENSING OF
ATMOSPHERIC WATER VAPOR BY GROUND BASED GPS
Chen Junyong
(National Bureau of Surveying and Mapping, Beijing, 100830)
Abstract Error analysis and evaluation for the remote sensing of atmospheric water vapor by using ground based GPS are discussed and presented in the paper. There are three main error resources in putation of atmospheric water vapor by using ground based GPS data. First is the error puted wet delay. It is resulted from putation of wet delay for the GPS signals transmission time. Second part is the error of the value of transformation factor Κ. The function of Κ is to transform atmospheric water vapor value from the wet delay. The third one is the error of the model which is the connection between water vapor and wet delay.
Keywords GPS, Weather forecast, Atmospheric water vapor, Precipitable water
摘要讨论并分析了利用地基GPS遥感大气水汽含量时的误差源及其数值评估。其误差来自三个方面:一是计算GPS讯号传输时间中湿延迟的误差;二是将该湿延迟转换为大气水汽含量公式中测定转换因子的误差;三是转换模型的误差。
关键词 GPS 天气预报大气水汽量可降水份
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1 引言http;//网
GPS接收机是一种应用于定位、导航的大地测量仪器。它的位置是由GPS卫星和接收机间的距离来确定,而这一距离实际上是通过测定卫星发出的并传输至接收机的无线电讯号的传播时间来求定的。这一传输时间受到传输途径上地球大气层的影响,与真空情况相比,就有畸变,其原因之一是对流层中的水汽的影响。对大地测量来说,为了精确定位和导航,必须消除或消弱地球大气层对GPS讯号传播的种种影响,即“噪声”。然而这种对大地测量的“噪声”,却是对大气科学的一种极为有用的“信息”。因为GPS无线电讯号的时间延迟是大气层中电离层和对流层综合作用的结果,一旦精确求定这一延迟,就可以反解电离层的电子浓度和对流层中的温度、湿度等。因此,GPS讯号可以成