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A. Hofmeister, D. Landskron, J. Böhm:
"Influence of the horizontal resolution of numerical weather models on ray-traced delays for VLBI analysis";
in: "Proceedings of the 22nd European VLBI Group for Geodesy and Astrometry Meeting", issued by: Rüdiger Haas and Francisco Colomer; European VLBI Group for Geodesy and Astrometry, 2015, ISBN: 978-989-20-6191-7, 162 - 166.

Ray-traced delays offer the opportunity to correct the influences of the troposphere on observations of space geodetic applications such as Very Long Baseline Interferometry (VLBI). As the Numerical Weather Model (NWM) builds the data base for the ray-tracing through providing the needed meteorological data, the selection of an appropriate NWM is of major concern. In this respect also the horizontal resolution of the NWM may have significant impact on the resulting ray-traced slant delays. So, directly on the ray-traced delays the horizontal resolution of the NWM shows an increasing impact with decreasing elevation angle. In case of using horizontal resolutions of either 0.125◦ x 0.125◦ or 1◦ x 1◦, real significance in terms
of differences in the resulting ray-traced delays is only given at elevation angles smaller than 10◦, as the differences start to exceed the cm-level at lower elevations. If the ray-traced delays are applied to the VLBI analysis of the CONT11 campaign, the horizontal resolution of the NWM has in general a very small influence with respect to Baseline Length Repeatability (BLR) and Station Coordinate Repeatability (S CR). Depending on the general parameterization of the analysis, the influence of the horizontal resolution of the NWM may even be negligible.

Ray-tracing, Troposphere, Numerical weather model, VLBI

https://publik.tuwien.ac.at/files/publik_242580.pdf