Estimation of rain height for slant-path attenuation prediction in tropical and equatorial climates

Radiosonde data were analyzed for 12 locations in Brazil to provide an estimation of the 0°C isotherm height. Monthly and seasonal variations as well as the relationship between the 0°C isotherm height and some ground meteorological parameters were examined. Also, the distribution of the 12 locations along the country permitted an evaluation of the latitudinal variations of the 0°C isotherm height. In addition to the radiosonde data, radiometric measurements carried out at Belem, Manaus and Rio de Janeiro provided slant-path rain attenuation distributions which were used together with CCIR current prediction methods in order to estimate the equivalent rain height h_R. Values thus obtained were then compared with the 0°C isotherm height