Variability of the 0° isotherm in the Iberian Peninsula

Rain attenuation prediction models often require rain height data that can be derived from the 0° isotherm height obtained as proposed in ITU-R recommendations and also from radiosonde measurements. A study on the height of the 0° isotherm has been performed using radiosonde data for sites located in various regions of Spain. Communication systems make use of fade mitigation techniques to compensate for the effects of propagation impairments such as rain attenuation. Systems incorporating such techniques must adapt to the variations in the propagation channel caused by various impairments, so that accurate information on the parameters that describe their variability is required. In this paper, statistical results on the behavior of the 0° isotherm are presented focusing on its temporal variability.