4.6 Article

A priori zenith wet delays in the analysis of VLBI CONT sessions

期刊

ADVANCES IN SPACE RESEARCH
卷 67, 期 8, 页码 2359-2367

出版社

ELSEVIER SCI LTD
DOI: 10.1016/j.asr.2021.01.027

关键词

Troposphere; VLBI; GNSS; Repeatability; Earth Orientation Parameters

向作者/读者索取更多资源

This study investigates the impact of including external GNSS estimates to model a priori Zenith Wet Delay (ZWD) in VLBI analysis, as well as other models of a priori ZWD. The results show that modelling a priori ZWD does not significantly affect baseline length and coordinates repeatabilities, but can change the estimated coordinates by a few millimeters in the up component, and has a small but significant impact on Earth Orientation Parameters (EOP) and troposphere estimates.
Tropospheric delay is one of the major sources of error in VLBI (Very Long Baseline Interferometry) analysis. The principal component of this error can be accurately computed through reliable surface pressure data -hydrostatic delay- yet there is also a small but volatile component -wet delay- which is difficult to be modelled a priori. In VLBI analysis, troposphere delay is typically modelled in the theoretical delays using Zenith Hydrostatic Delays (ZHD) and a dry mapping function. Zenith Wet Delay (ZWD) is not modelled but estimated in the analysis process. This work studies inter alia the impact of including external GNSS estimates to model a priori ZWD in VLBI analysis, as well as other models of a priori ZWD. In a first stage, two different sources of GNSS troposphere products are compared to VLBI troposphere estimates in a period of 5 years. The solution with the best agreement to VLBI results is injected in the VLBI analysis as a priori ZWD value and is compared to other options to model a priori ZWD. The dataset used for this empirical analysis consists of the six CONT campaigns. It has been found that modelling a priori ZWD has no significant impact either on baseline length and coordinates repeatabilities. Nevertheless, modelling a priori ZWD can change the magnitude of the estimated coordinates a few millimeters in the up component with respect to the non-modelling approach. In addition, the influence of a priori ZWD on Earth Orientation Parameters (EOP) and troposphere estimates -Zenith Total Delays (ZTD) and gradients-has also been analysed, resulting in a small but significant impact on both geodetic products. (C) 2021 COSPAR. Published by Elsevier B.V. All rights reserved.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.6
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据