Relationships between attenuation at different frequencies, based on initial data extracted from meteorological radiosoundings and physical models

Abstract:
In this paper, some results are presented regarding the relationships between attenuation at different frequencies, in the slant path. The data (height, pressure, relative humidity and temperature), which support the basis of the study, have been obtained from meteorological radiosoundings in stations located all over the globe. From them, the zenith attenuation has been calculated at different frequencies using physical models. The studied frequencies range from 12 to 100 GHz, in intervals of approximately 10 GHz. The results concern the similarities between two sets of frequencies, in the first place, 12, 20, 30, 40 and 49.5 GHz and in the second place 60, 70, 80, 90 and 100 GHz. The water vapour absorption influences the first set, while the second one is mostly influenced by the oxygen band around 60 GHz. Crossed relationships between frequencies of both sets have also been investigated. Among all of this, it has been found that it is possible in most cases to extract some type of relationships between the parameters (attenuation and others), in the absence of rain, but this relationships are not useful for all places, but they may be tuned with regards to the climatic zone, sea proximity, height of the station, etc.