Optimal time lags to use in modeling the thermal deformation of VLBI Antennas
Abstract
One of the most significant effects on VLBI antennas is thermal expansion which can change the height of the VLBI reference point by as much as 20mm. In this paper, we investigate how using a thermal expansion model in VLBI processing improves the solution, as well as the optimal time delay for the variations in temperature to introduce for the steel telescope structure and for a concrete structure. We use the software Solve and the conventional model of Nothnagel 2009 implemented in Solve. We compare different solutions processed using the R1 and R4 sessions from January 2002 to March 2011: 1) not using the thermal expansion model, 2) using it with no time delay and then 3) different time delays. We show that using the thermal deformation model improves the baseline length repeatability of the solutions by more than 1mm and for more than 75 % of the baselines, as well as reduces the WRMS per station.
- Publication:
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21st Meeting of the European VLBI Group for Geodesy and Astronomy
- Pub Date:
- August 2013
- Bibcode:
- 2013evga.conf..165L
- Keywords:
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- Geodetic VLBI analysis and modeling