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

Paper in 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.