中文摘要：

电离层延迟是空间大地测量数据处理中一项重要误差源.电离层延迟可以根据电子含量分布图（IM）以及映射函数模型计算得到.本文以IGS、JPL和NOAA提供的电子含量分布图为例,比较了这些电子含量分布图在给定台站的不同观测高度角穿刺点上的天顶电子含量,并比较了采用单层和双层球壳映射函数模型获得的斜路径电子含量.分析结果显示两种映射函数模型在计算斜路径的影响差别不大.JPL的天顶电子含量影响总要比IGS的大约3TECU左右,呈现出明显的系统差.NOAA与IGS的系统差则相对不明显,个别台站的差值较大.表明不同GPS数据分析中心获得的电子含量分布图模型存在一定的系统差,在实际运用中应考虑这些差异.

英文摘要：

Ionospheric delay is one of the important errors in the space geodetic data analysis.Usually,the ionospheric delay can be derived from the Ionospheric Map（IM） with mapping functions. In this paper, we compard the vertical total electron contents（TEC） from IGS,JPL and NOAA IMs, on the pierce points with different elevations at given stations,and compared the Slant TEC calculated with the single and double layers spherical shell model.The comparisons show that the JPL VTEC are about 3TECU greater than that of IGS,illustrating clear systematic bias.The VTEC difference between NOAA and IGS looks random,while shown large difference at individual station.It suggests that the TEC from different analysis centers may have some system errors and should be taken into account in the ionospheric delay calibration.