Cloud and gases attenuation by radiometer measurements

The use of 20/30/40 GHz for satellite or high altitude platform based SHF and EHF communication systems will offer bandwidths not available at lower microwave frequencies. The troposphere attenuation is however a more serious problem and models oriented to take into account only rain effects are not appropriated to model the channel, mainly if low fade margin systems are our target. Clouds, gases, light rain and scintillation fades must be considered. Some difficulties arises from the fact that some of this attenuation contributions are weekly correlated with ground meteorological data and direct measurements to develop, test and improve the models are very scarce