scholarly journals The Speed Electromagnetic Wave Propagation in the Snow-Ice Underlying Surface

2021 ◽  
pp. 332-346
Author(s):  
Vladimir A. Malyshev ◽  
Viktor G. Mashkov
Keyword(s):  
Wave Propagation ◽  
Electromagnetic Wave ◽  
Water Content ◽  
Liquid Water ◽  
Electromagnetic Waves ◽  
Electromagnetic Wave Propagation ◽  
Liquid Water Content ◽  
Ice Cover ◽  
Underlying Surface ◽  
Speed Propagation

The results calculations the electromagnetic wave propagation velocity in the snow-ice cover depending on the density, the proportion liquid water content, and the propagation speeds the electromagnetic wave in dry snow, dry firn, and dry ice vary very markedly depending on the proportion liquid water content, the preferred orientation, and the shape ice and air structure are presented. The inclusions in the snow. The performed estimates the complex relative permittivity the medium that determines the speed propagation electromagnetic waves show a noticeable influence the density, the proportion liquid water content and the structure the underlying surface (snow, firn, ice), which allows identifying the layers the underlying surface in order to remotely determine the possibility landing a helicopter-type aircraft on an unprepared site with snow-ice cover. Shown, when the portion the water content in the medium is equal to zero, which is typical for negative temperatures, the speed propagation electromagnetic waves in the medium will depend on the density the medium and structure the dry ice in a small range of 1 m/μs temperature. In dry snow, vertically and horizontally elongated or spherical inclusions make a significant contribution to the change in the speed propagation the electromagnetic wave. At zero temperature, in the frequency range of 2 ... 8 GHz, the share water content in the medium, the density and structure the medium will play a determining role in the speed propagation an electromagnetic wave in the medium. The purpose this article is to determine the change ranges speed propagation electromagnetic waves in snow-ice the underlying surface depending on the density, structure, water content to restore the structure the snow and ice according to radar sensing, a more accurate determination the depth snow and thickness ice cover used in the assessment the possibility the safe landing an aircraft the helicopter type on an unprepared ground with snow-ice cover

Electromagnetic wave propagation in a chiroplasma-filled waveguide

1999 ◽  
Vol 62 (1) ◽  
pp. 87-94 ◽  
Author(s):  
J. GONG
Keyword(s):  
Wave Propagation ◽  
Electromagnetic Wave ◽  
Cross Section ◽  
Electromagnetic Waves ◽  
Electromagnetic Wave Propagation ◽  
Propagation Constant ◽  
Circular Cross Section ◽  
Propagation Characteristics ◽  
Waveguide Modes ◽  
The Family

A dispersion equation is derived for a cylindrical waveguide of circular cross-section partially filled with chiroplasma. The propagation characteristics of electromagnetic waves in the family of waveguide modes are studied. The dispersion curves are given. It is found that the propagation constant changes almost linearly with the chirality admittance for the parameters that we choose, and increases with increasing filled area.

Rayleigh surface waves along the boundary between a plasma and a metallic screen

1993 ◽  
Vol 49 (2) ◽  
pp. 227-235 ◽  
Author(s):  
S. T. Ivanov ◽  
K. M. Ivanova ◽  
E. G. Alexov
Keyword(s):  
Wave Propagation ◽  
Electromagnetic Wave ◽  
Surface Waves ◽  
Electromagnetic Waves ◽  
Electromagnetic Wave Propagation ◽  
Cyclotron Frequency ◽  
Plasma Frequency ◽  
Magnetoactive Plasma ◽  
Rayleigh Surface Waves ◽  
The Waves

Electromagnetic wave propagation along the interface between a magnetoactive plasma and a metallic screen is investigated analytically and numerically. It is shown that the waves have a Rayleigh character: they are superpositions of two partial waves. It is concluded that electromagnetic waves propagate only at frequencies lower than min (ωp, ωc), where ωpis the plasma frequency and ωcis the cyclotron frequency. The field topology is found, and the physical character of the waves is discussed.

Impact of Rough Wall Surface on Electromagnetic Wave Propagation Characteristics in Mine Tunnels

2011 ◽  
Vol 301-303 ◽  
pp. 1417-1421
Author(s):  
Shan Hua Yao ◽  
Xian Liang Wu
Keyword(s):  
Wave Propagation ◽  
Electromagnetic Wave ◽  
Coal Mine ◽  
Electromagnetic Waves ◽  
Electromagnetic Wave Propagation ◽  
Rough Wall ◽  
Wall Surface ◽  
Propagation Characteristics ◽  
Waves Propagation ◽  
Mine Tunnels

In this paper ,the mine tunnels is regard as wave-guide which contains kinds of un-beneficial medium, we have study the formulas of electromagnetic waves propagation attenuation and roughness attenuation, the relations between propagation attenuation and roughness and frequency were simulated. The results show that the influence of propagation attenuation in lower frequency is more obvious, and roughness attenuation is increased rapidly as roughness of coal mine tunnels increasing. But tilted attenuation is stronger than roughness attenuation as propagation frequency increasing.

scholarly journals NUMERICAL METHOD FOR ELECTROMAGNETIC WAVE PROPAGATION PROBLEM IN A CYLINDRICAL INHOMOGENEOUS METAL DIELECTRIC WAVEGUIDING STRUCTURES

2017 ◽  
Vol 22 (3) ◽  
pp. 271-282 ◽  
Author(s):  
Eugene Smolkin
Keyword(s):  
Wave Propagation ◽  
Electromagnetic Wave ◽  
Electromagnetic Waves ◽  
Electromagnetic Wave Propagation ◽  
Physical Problem ◽  
Dielectric Waveguides ◽  
Spectral Parameters ◽  
Transmission Eigenvalue ◽  
Wave Propagation Problem ◽  
Transmission Eigenvalue Problem

The propagation of monochromatic electromagnetic waves in metal circular cylindrical dielectric waveguides filled with inhomogeneous medium is considered. The physical problem is reduced to solving a transmission eigenvalue problem for a system of ordinary differential equations. Spectral parameters of the problem are propagation constants of the waveguide. Numerical results are found with a projection method. The comparison with known exact solutions (for particular values of parameters) is made.

scholarly journals Spatiotemporal Variations in Liquid Water Content in a Seasonal Snowpack: Implications for Radar Remote Sensing

2021 ◽  
Vol 13 (21) ◽  
pp. 4223
Author(s):  
Randall Bonnell ◽  
Daniel McGrath ◽  
Keith Williams ◽  
Ryan Webb ◽  
Steven R. Fassnacht ◽  
...  
Keyword(s):  
Water Content ◽  
Liquid Water ◽  
Electromagnetic Waves ◽  
Snow Water Equivalent ◽  
Canopy Cover ◽  
Liquid Water Content ◽  
Spatiotemporal Variability ◽  
Snow Density ◽  
Wet Snow ◽  
Observation Method

Radar instruments have been widely used to measure snow water equivalent (SWE) and Interferometric Synthetic Aperture Radar is a promising approach for doing so from spaceborne platforms. Electromagnetic waves propagate through the snowpack at a velocity determined by its dielectric permittivity. Velocity estimates are a significant source of uncertainty in radar SWE retrievals, especially in wet snow. In dry snow, velocity can be calculated from relations between permittivity and snow density. However, wet snow velocity is a function of both snow density and liquid water content (LWC); the latter exhibits high spatiotemporal variability, there is no standard observation method, and it is not typically measured by automated stations. In this study, we used ground-penetrating radar (GPR), probed snow depths, and measured in situ vertically-averaged density to estimate SWE and bulk LWC for seven survey dates at Cameron Pass, Colorado (~3120 m) from April to June 2019. During this cooler than average season, median LWC for individual survey dates never exceeded 7 vol. %. However, in June, LWC values greater than 10 vol. % were observed in isolated areas where the ground and the base of the snowpack were saturated and therefore inhibited further meltwater output. LWC development was modulated by canopy cover and meltwater drainage was influenced by ground slope. We generated synthetic SWE retrievals that resemble the planned footprint of the NASA-ISRO L-band InSAR satellite (NISAR) from GPR using a dry snow density model. Synthetic SWE retrievals overestimated observed SWE by as much as 40% during the melt season due to the presence of LWC. Our findings emphasize the importance of considering LWC variability in order to fully realize the potential of future spaceborne radar missions for measuring SWE.

Electromagnetic wave propagation in an inhomogeneous gyrational medium

1971 ◽  
Vol 69 (3) ◽  
pp. 457-463 ◽  
Author(s):  
B. S. Westcott
Keyword(s):  
Wave Propagation ◽  
Electromagnetic Wave ◽  
Electromagnetic Waves ◽  
Electromagnetic Wave Propagation ◽  
Transmission Coefficients ◽  
Resonance Properties

AbstractThe investigation of a recently devised model in which the permittivity profile takes the form of an asymmetrical Epstein layer is adapted for use in a gyrational medium. Reflexion and transmission coefficients for normally incident electromagnetic waves are obtained and resonance properties are discussed.

scholarly journals Determination of the Water Content of Snow from the Study of Electromagnetic Wave Propagation in the Snow Cover

1978 ◽  
Vol 20 (84) ◽  
pp. 585-592
Author(s):  
J. Tobarias ◽  
P. Saguet ◽  
J. Chilo
Keyword(s):  
Wave Propagation ◽  
Electromagnetic Wave ◽  
Snow Cover ◽  
Water Content ◽  
Electromagnetic Wave Propagation ◽  
Working Frequency

AbstractWe propose a method for measuring in situ and continuously, the water content of a sample of snow in the snow cover. This method is based on the measurement of the attenuation of an electromagnetic wave propagating in a sample of snow situated between two antennae, an emitter and a receiver. The working frequency is 9.4 GHz.

Parameter Estimation for Evaluation of in Situ Density and Moisture Content by using Elastic and Electromagnetic Wave Propagation

2008 ◽  
Vol 2045 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Bashar Alramahi ◽  
Dante Fratta ◽  
Khalid A. Alshibli
Keyword(s):  
Quality Control ◽  
Wave Propagation ◽  
Quality Assurance ◽  
Electromagnetic Wave ◽  
Moisture Content ◽  
Water Content ◽  
Electromagnetic Wave Propagation ◽  
Soil Density

Soil density and moisture content are two essential properties in the quality control and quality assurance of projects that involve soil compaction. However, current field practices either are destructive and time-consuming (i.e., sand cone or water balloon for soil density and oven drying for moisture content) or include hazardous substances that require special handling and operating procedures (i.e., nuclear density gauge). Therefore, new robust, reliable, and nonnuclear techniques for the determination of in situ density and moisture content would assist in quality control and quality assurance processes and would allow more measurements to be performed in a shorter time. A methodology for the in situ determination of density and moisture content by using the propagation of elastic and electromagnetic waves through soils was evaluated. It is based on a semiempirical model that relates elastic wave velocity through soils to the water content, porosity, and degree of saturation. An experimental program was used to verify the model and examine its range of applicability. It was also used to examine the accuracy and limitations of the suggested methodology. An analysis was made of the experimental assessment, along with a detailed numerical study of the inversion procedure used to calculate the density and moisture content. Although the parametric and experimental study shows that the methodology can provide an estimate of density and water content rapidly and non-destructively, there are inherent accuracy and precision limitations that need to be solved. These results also show that combined elastic and electromagnetic wave propagation measurements can help in the development of a methodology that may assist in solving inconsistencies in stiffness measurements.

scholarly journals Determination of the Water Content of Snow from the Study of Electromagnetic Wave Propagation in the Snow Cover

1978 ◽  
Vol 20 (84) ◽  
pp. 585-592 ◽  
Author(s):  
J. Tobarias ◽  
P. Saguet ◽  
J. Chilo
Keyword(s):  
Wave Propagation ◽  
Electromagnetic Wave ◽  
Snow Cover ◽  
Water Content ◽  
Electromagnetic Wave Propagation ◽  
Working Frequency

Abstract We propose a method for measuring in situ and continuously, the water content of a sample of snow in the snow cover. This method is based on the measurement of the attenuation of an electromagnetic wave propagating in a sample of snow situated between two antennae, an emitter and a receiver. The working frequency is 9.4 GHz.

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