AIRBORNE DUST SIZE ANALYSIS FOR TROPOSPHERIC PROPAGATION OF MILLIMETRIC WAVES INTO DUST STORMS

Abstract

The authors present a study of five dust storms that occurred in Riyadh, Saudi Arabia together with their effect on millimeter-wave propagation. Meteorological parameters are given and the 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. On the basis of measurements and analysis, attentuation at 37 GHz is calculated in terms of optical visibility as a storm parameter. It is found that the probability distributions are best described by a normal or lognormal fit and vary with dust-storm conditions. The average effective size and the 37-GHz attenuation decrease with the increase of antenna height following a power law