Microwave Attenuation and Phase Rotation by Ellipsoidal Dust Particles

Abstract

Electromagnetic wave propagation suffers attenuation and phase rotation by suspended dust particles especially in arid and semi-arid regions where occurrence of sand and dust storms (SDS) is predominant. The SDS phenomenon has received considerable interest in recent times with emphasis on signal attenuation and phase rotation effects. To this end, mathematical models of dust induced complex scattering are developed and proposed in this paper using Rayleigh method to compute attenuation and phase rotation of electromagnetic waves by considering dust particle shapes and best fit ellipsoids. This work also presents a new expression for the relation between visibility and dust concentration. The expression was included in the proposed models whose simulated results, compared with some published results, show close agreement. Attenuation and phase rotation in dry dust are found to be significant only when visibility becomes severe or at increased microwave bands.

Earth and Martian Sand and Dust Storms: A Comprehensive Review of Attenuation Modelling and Measurements

“…The surface charges on the SD particles [174] are considered among the various reasons to explain why the observed values for attenuation are much higher than the predicted values [203][204]. Many factors contribute to the charge on SD particles, including friction [196], contact [195][177], and frequent particle collisions [192,193]. If we consider SD particles as an equivalent dielectric spheres, then in an electric field, dielectric SD particles become polarized, resulting in the accumulation of charge on both sides of the sand spheres.…”

“…The models discussed were only suitable in the context of spherical particle. In [196], the authors presented models in terms of charge-to-mass ratio, charge distribution angle, and intensity of incident waves for both spherical particles and ellipsoidal particles. Moreover, they also considered monodisperse and poly-disperse medium.…”

“…Derived for lognormal distribution using the relationship between the number of dust particles and visibility [196]Musa…”

“…• Does not consider ellipsoidal particles • Simulation results are not compared with any model [196] • Consider monodispersive and polysidpersive medium • Valid upto 37GHz…”

The quadruple helix model of innovation for Industry 4.0

“…In addition, Dlamini, Bokoro and Doorsamy (2018) reviewed commonly applied techniques for condition monitoring to improve online and remotely applied monitoring. Digitisation brings about electromagnetic noise replacing audible noise, and Musa and Paul (2018) used a theoretical approach for predicting the attenuation of electromagnetic wave propagation. These examples are not directly related to the FIR; however, they are fundamentally induced by the capabilities of modern technology.…”