Comparison of attenuation measurements at 19.7 GHz from radiometer observations, GNSS delay data and radiosondes

A single-channel radiometer operating at 19.7 GHz has been working at Universidad Politécnica de Madrid with the aim of retrieving atmospheric attenuation under non-scattering conditions. With the purpose of validating these estimates, they have been compared with attenuation values obtained by a GNSS receiver and radiosondes. From the first results obtained, the three instruments agree quite well. However, GNSS is considered the best option to evaluate concurrent radiometric time-series due to its better time resolution. Single comparisons between radiometer and GNSS, as well as visual inspections of data, suggest that the combined analysis of measurements of both instruments can provide useful inputs during satellite propagation experiments.