The Nature, Amplitude and Control of Microwave Attenuation in the Atmosphere

Abstract

Microwave (MW) attenuation plays a critical role in constructing communication networks. It also can be a useful tool in the meteorological and optical communities for radar and microwave imaging applications. Because most atmospheric constituents (large hydrometeors being an exception) are very small compared to MW wavelengths, data analysis is typically performed using conventional Rayleigh theory; however, some anomalous observations have proven difficult to explain. We present the results of the first systematic numerical computations over a wide range of aerosol properties. We demonstrate that it is possible to perform mass computations of aerosol loading, which is an important climate parameter. We show that discrepancies found between theoretical predictions and observations can be attributed to the effect of the expected charge acquired by the dust particles through contact electrification occurring in dust storms. While frequencies below 10 GHz normally allow for long‐distance signal transmission, the charge‐induced resonances in particles can preferentially amplify the low‐frequency MW attenuation by a factor of 10 or more, depending on their surface electric potential. In addition, we find electrically charged particles dispersed in a local atmosphere as a potential tool for the controlled manipulation of MW attenuation.

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

“…They concluded that in normal circumstances, the presence of charges on the particle enhances the scattering EM wave in the backward direction, however the scattering of EM wave relies on factors such as particle size, frequency and refractive index. The investigation of EM wave field scattered off a charged particle were also reported in [115], where the authors presented the numerical results demonstrating the potential to modify the scattering field of the EM wave by adjusting the particle's surface potential, while keeping the incident wavelength, refractive index, and temperature constant. Therefore, they proposed a mathematical expression for the surface electric potential and the relative refractive index of a charged particle in terms of the amplitude ratio and phase difference of the dispersed electric field's transverse components results.…”

An Innovative model of magnetically intercalated expanded graphite for calculating radar attenuation performance at 2–18 GHz

“…MEGs have been widely used as coating filters, and their reflection loss performance were well-studied [ [21] , [22] , [23] , [24] , [25] ], which indicates addition of magnetic materials can effectively reduce radar wave reflection of materials. When the MEG is used in a form of large-area aerosol, its radar jamming efficiency greatly depends on absorption and scattering functions of each MEG particles, which, however, cannot be obtained by traditional laminate-based measurement methods (such as vector network instrument) [ 26 , 27 ]. Currently, there are some experimental methods that can measure attenuation performance of large-area aerosol, but the absorption and scattering behaviors occurring on the surface and inside of a single particle are not easy to show through experimental methods, which makes it difficult to explain the attenuation mechanism in detail [ 13 , 28 ].…”