Speaker
Description
Since mid-2023, the Onsala Space Observatory has been operating a new modern microwave water vapor radiometer (WVR), Greta, which is a commercial product of type HATPRO-G5. It is co-located with the other microwave radiometer, Konrad, which has been developed and built at Onsala. Konrad has been in operation since 2000 and is usually operated in so-called sky-mapping mode. Usually, the data of complete sky-scanning sequences are then analyzed together, providing zenith wet delay and wet horizontal gradient results with a temporal resolution of 2–5 minutes. In addition to operating in a similar sky-mapping mode, the new WVR Greta has been operated in synchronization with VGOS observations during several VGOS 24-h and VGOS-INT sessions in 2023 to 2024. This means that Greta was performing measurements of the local atmosphere in the same direction as the VGOS telescopes at Onsala, thus providing slant wet delay measurements for each VGOS observation. Together with the slant hydrostatic delays calculated from ground pressure measurements, the possibility of avoiding estimating the delays due to the neutral atmosphere exists and will be evaluated. We also investigate the agreement between the tropospheric parameters estimated from VGOS and those retrieved by the synchronized WVR observations.
