全球对流层延迟模型的质量评价

对常用的3种天顶对流层延迟改正模型(Saastamoninen模型、Hopfield模型和EGNOS模型)进行误差分析，代入气象元素及测站位置误差，得出各模型的ZTD估值受误差影响的程度。使用C++语言实现以上3种模型，选取一系列不同纬度和高程的IGS站，利用IGS分析中心提供的气象文件，结合测站时空信息，导入程序进行模拟计算，并与IGS对流层产品进行比较，对改正模型进行质量评价。结果表明，Saastamoninen模型和Hopfield模型能够较准确地根据地面气象资料反映对流层延迟的日变化，Saastamoninen模型的改正精度略高于Hopfield模型；同时，无需实测气象资料的EGNOS模型RMS小于0.1 m，也可满足GNSS m级定位需求。

Quality Evaluation of Global Tropospheric Delay Model

Giving error analysis on three frequently used zenith tropospheric delay correction models, including the Hopfield, Saastamoninen and EGNOS models, combined with the errors of meteorological elements and station position, this study obtains the degree to which the errors affect the assessment value of ZTD. Then, achieving the three models by C++ language, selecting a series of IGS station at different latitudes and elevations, using meteorological data provided by IGS Analysis Center, combined with the time and space information of the station, this paper calculates the real ZTD. Compared with the IGS troposphere products, the estimation of quality of the three models is achieved. The results show, according to the meteorological data, Saastamoninen and Hopfield model could reflect the changes of tropospheric delay in a certain day accurately. The corrective precision of Saastamoninen model is slightly higher than that of Hopfield model. The EGNOS model does not need the measured meteorological data. Meanwhile, its RMS is less than 0.1 m, and can also meet the requirement of GNSS meter level localization accuracy.