14 participants (scientists, operators, manufacturers) from 6 different countries met at the Research Centre Jülich (Germany) from 31 August to 2 September 2022 for a workshop on the operation of ground-based microwave radiometers. The workshop was organized by the University of Cologne in the frame of the ACTRIS Centre for Cloud Remote Sensing (CCRES) and with support from the COST Action PROBE (www.probe-cost.eu).
The University of Cologne has a long experience (>15 years) in the field of ground-based microwave radiometry and hosts the topical centre for microwave radiometry within CCRES. Microwave radiometers are increasingly used in observational networks across Europe, in order to observe boundary layer temperature profiles as well as integrated water vapour and cloud liquid water. These instruments are also a mandatory component of ACTRIS NF (National Facilities) for Cloud Remote Sensing. In order to assure high data quality, the operators need to perform regular calibrations and other tasks. This workshop gave an overview of these topics and contained also some practical training.
The workshop started with some background in microwave radiometry theory, applications, and retrieval development. On the first afternoon, we had a visit from a representative of the main radiometer manufacturing company (Radiometer Physics GmbH). We had a very good and fruitful exchange between new developments at the company and own experiences with the participants. The second day was dedicated to practical experiences, everyone was able to follow calibrations using liquid nitrogen as well as the exchange of a radome. On the last day, we wrapped up this workshop with some information on radiometer operation in ACTRIS and new data processing software tools.