Atmospheric parameters derived from VGOS sessions observed with the Onsala twin telescopes

Paper i proceeding, 2023

We compare the atmospheric parameters
derived from the analysis of VGOS sessions that were
observed with the Onsala twin telescopes to the
corresponding results derived from co-located GNSS
stations and a ground-based microwave radiometer at
Onsala. The focus is on the first four VGOS Research
& Development sessions, observed in 2021 and 2022,
aimed at testing scheduling strategies with short scan
length in order to obtain a good local sky coverage.
The data analysis of all three techniques allows a high
temporal resolution of 5 min for the atmospheric
parameters. We find high correlation (0.97) for the
zenith total delays of the three techniques, and
pair-wise weighted root mean square difference on
the order of 4–10 mm. The linear horizontal delay
gradients are less well correlated (0.4–0.5) and have
pair-wise weighted root mean square differences in
the sub-mm range.