Water Vapor Retrieval to Support Electromagnetic Wave Propagation Experiments: Results from Different Techniques

The accuracy of different techniques in retrieving the integrated water vapor (IWV) is assessed. Specifically, radiosonde observation (RAOBS) data collected in two sites with different climatic conditions (Milan, Italy, and Uccle, Belgium) are used as a reference to evaluate the accuracy of IWV values extracted from the ERA5 database of the European Centre for Medium-range Weather Forecast, as well as retrieved from a microwave radiometer (MWR) and GNSS receivers. Results indicate that the MWR provides the most accurate estimate of the IWV, but also that all the considered IWV data sources can satisfactorily serve the purpose of supporting the derivation of the total tropospheric attenuation from the received beacon signal in electromagnetic wave propagation experiment.