Accurate Analytical Model of Equivalent Dielectric Constant for Rain Medium

Abstract

In this paper, rain medium is considered as random statistically isotropy mixture, formed by distributing different shape and size raindrops following some raindrop-spectrum in atmosphere. The accurate analytical formula to calculate dielectric constant of rain medium is deduced, which take the influences of ⟨P⟩ and P on the field in rain region and raindrop inside and the effect of shape of raindrop on dielectric constant of raindrop into account. The condition of taking rain medium as continuous medium is discussed, and the dielectric constant of raindrop is found, if the condition is not satisfied. The important fact is that the interaction between targets in rain and rain medium can be expediently researched by the formula given in this paper. Attenuation of rain is computed using the conclusion in this paper, which is explanatorily compared with attenuation measured. The way applied in this paper is valid for other discrete medium, fog, dust storm, for example.