Airborne Dust Size Analysis for Tropospheric Propagation of Millimetric Waves into Dust Storms

This paper presents a study of five dust storms that occured in Riyadh together with their effect on millimeter-wave propagation. Meteorological parameters are given and airborne-dust´s permittivity is estimated using relative humidity data. For large particles, the size distribution and its height dependence are investigated experimentally and the findings are presented as a functional relationship. Based on actual measurements and analysis, attenuation at 37 GHz is calculated using a newly derived expression in terms of optical visibility as a storm parameter. It is found that the fitted probability distributions are best described by normal or lognormal and vary with duststorm conditions. The average effective sizes and the 37-GHz attenuation decreases with the increase of antenna height following a power law.