Radiometry performance of the VGOS receivers of the Onsala twin telescopes

Paper in proceeding, 2023

We have assessed to stability of the present
VGOS receivers in the Onsala twin telescopes (OTT) in
order evaluate the possibility to use them to estimate
the wet propagation delay of the atmosphere. As expected
the highest possible frequencies that can be
used in the present OTT receivers, 15.3 to 15.6 GHz,
are too far from the centre of the water vapour emission
line at 22.2 GHz in order to be meaningful for critical
assessments of the wet delays estimated from the
VLBI data themselves. However, we do find clear correlations
between the wet delays estimated from the
VGOS receivers with those provided by a traditional
stand-alone microwave radiometer.