卫星VLBI测轨资料处理中的电离层延迟改正

结合我国探月项目卫星VLBI测轨资料分析中的实际需求讨论了两个问题：一是在S、X波段时延测量精度均为1ns情况下，电离层延迟改正所能够达到的精度；二是在飞行器VLBI测轨过程中，不能确保S、X波段双频观测情况下获取电离层时延改正的可能途径，包括借助于相关电离层模型、利用常规VLB1历史观测资料积累、借助于局域GPS观测网和IGS网单站GPS测量以及借助于专门设计的单站GPS测量等。最后对电离层VLB1和GPS技术实测结果进行了比较和问题分析。

On the Ionospheric Delay Correction in the Processing of Satellite VLBI Observations

Two subjects are involved in accordance with the data processing of satellite VLBI observations in the national lunar project. One is about the error budget of the ionospheric delay correction with the presumably known uncertainties of the delay observation in S and X band as 1ns. The other is about the possible means to correct the ionospheric effect in case of the unavailable observations in S/X dual bands. General characteristics is reviewed and discussed on the ionosphere reference models, the historical accumulation of astrometric and geodetic VLBI observations, local GPS network, GPS receiver within the IGS network as well as individual GPS receiver with particular designation of settings and supplement infrastructure. The comparison of the Total Electronic Content (TEC) resulted from VLBI and GPS is presented in order to demonstrate the current status of related studies.