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NUMERICAL ESTIMATION OF THE COMPLEX REFRACTIVE INDEXES BY THE ALTITUDE DEPENDING ON WAVE FREQUENCY IN THE IONIZED REGION OF THE EARTH ATMOSPHERE FOR MICROWAVES INFORMATION AND POWER TRANSMISSIONS
摘要： The phase and group refractive indexes of microwaves in the ionosphere region of the earth atmosphere are very important for both the researching theoretical problems and practical problems in wireless information transmission (WIT) and wireless power transmission (WPT). So far, there have been many attempts devoted to discussing and determining characterizations of earth atmosphere’s ionosphere region including the refractive indexes of microwaves concerning their velocities in ionized region, unfortunately due to the complicated features of the ionosphere region leading to research task facing many challenges. Up to recent, there is still a lack of systematic numerical data of complex refractive index by altitude depending on high frequencies of the electromagnetic waves in the ionosphere region. This paper outlines some theoretical analyses and discussions of some theoretical aspects of the complex refractive index in atmosphere’s ionized region more in detail. Based on conductivities data and the complex relative permittivity by altitude determined previously, the numerically estimated data of complex refractive indexes by the altitude from 100 km up to 1000 km at the di?erent frequencies are also shown and discussed.
关键词： wireless information transmission,refractive index,microwaves,ionosphere,wireless power transmission
更新于2025-09-23 15:21:21
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[IEEE 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Odessa, Ukraine (2018.9.4-2018.9.7)] 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - The Action of Ultra-Short Super-Powerful Radio Pulses on the Earth's Atmosphere and Ionosphere
摘要： Numerical simulations of disturbances in the electron temperature and density arising from the action of ultra-short super-powerful radio pulses with different durations and powers on the Earth's atmosphere and ionosphere are presented. It is demonstrated that the electron density in the 30–60 km altitude range can be increased by 12 orders of magnitude, while the electron temperature shows an increase of the order of 10 to 100 times. The pulse durations and powers needed to create artificial ionized layers have been estimated.
关键词： ultra-short radio pulse,disturbances,numerical simulation,atmosphere,electron temperature,ionosphere,super-powerful radio pulse,electron density
更新于2025-09-23 15:21:21
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Electrodynamic influence on the diurnal behaviour of neutral daytime airglow emissions
摘要： The diurnal variations in daytime airglow emission intensity measurements at three wavelengths OI 777.4 nm, OI 630.0 nm, and OI 557.7 nm made from a low-latitude location, Hyderabad (17.5? N, 78.4? E; 8.9? N MLAT) in India have been investigated. The intensity patterns showed both symmetric and asymmetric behaviour in their respective diurnal emission variability with respect to local noon. The asymmetric diurnal behaviour is not expected considering the photochemical nature of the production mechanisms. The reason for this observed asymmetric diurnal behaviour has been found to be predominantly the temporal variation in the equatorial electrodynamics. The plasma that is transported across latitudes due to the action of varying electric field strengths over the magnetic equator in the daytime contributes to the asymmetric diurnal behaviour in the neutral daytime airglow emissions. Independent magnetic and radio measurements support this finding. It is also noted that this asymmetric diurnal behaviour in the neutral emission intensities has a solar cycle dependence with a greater number of days during high solar activity period showing asymmetric diurnal behaviour compared to those during a low solar activity epoch. These intensity variations over a long timescale demonstrate that the daytime neutral optical emissions are extremely sensitive to the changes in the eastward electric field over low and equatorial latitudes.
关键词： Ionosphere (equatorial ionosphere–atmosphere interactions),Atmospheric composition and structure (airglow and aurora)
更新于2025-09-23 15:19:57
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[IEEE 2020 IEEE International Solid- State Circuits Conference - (ISSCC) - San Francisco, CA, USA (2020.2.16-2020.2.20)] 2020 IEEE International Solid- State Circuits Conference - (ISSCC) - 19.2 A 110mK 295?μW 28nm FDSOI CMOS Quantum Integrated Circuit with a 2.8GHz Excitation and nA Current Sensing of an On-Chip Double Quantum Dot
摘要： An electromagnetic wave propagating through the ionosphere is subject to path delay and the depolarizing effect of Faraday rotation, both of which are dependent on global position and geometry. These effects introduce error and consequently reduce the range resolution of remote sensing polarimetric measurements. Satellite-to-ground communications may be adversely altered by these effects so as to inhibit signal reception. The work presented here introduces a simple vectorized model for a large-field-of-view, low-Earth-orbit, satellite system that yields Faraday rotation and path delay according to global position and geometric parameters. Comparison is made with current models, through the simulation of Faraday rotation and path delay. The presented work may extend the range over which Faraday rotation and path delay estimation are reliable. The work presented forms part of a large-field-of-view, low-Earth-orbit satellite model exploiting multiple-input multiple-output polarimetry in three dimensions.
关键词： remote sensing,Faraday rotation,ionosphere,path delay,satellite communications
更新于2025-09-23 15:19:57
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Analysis of Electromagnetic Wave Propagation in Variable Magnetized Plasma via Polynomial Chaos Expansion
摘要： A three-dimensional stochastic FDTD algorithm is developed and applied to electromagnetic wave propagation in collisional magnetized plasma characterized by a variable electron density, collision frequency, and background magnetic ?eld. The proposed stochastic model is based on the expansion of the random / variable time-domain electric and magnetic ?elds in terms of orthogonal polynomials in independent random variables representative of the variable ionospheric content. Electromagnetic wave propagation in magnetized plasma having low variability (small deviations) and also high variability (large deviations) of the electron density, collision frequency, and background magnetic ?eld is studied. The stochastic algorithm is validated against brute-force Monte Carlo results. The algorithm is considerably more computationally ef?cient than Monte Carlo. When applied to electromagnetic wave propagation in the ionosphere, the variability of the Earth’s magnetic ?eld and ionospheric parameters can be accounted for due to naturally varying space weather conditions and day-to-day variations, measurement errors, etc. Although only electrons are considered here, positive and negative ions may be accommodated in a straight-forward manner.
关键词： ?nite-difference time-domain (FDTD),electromagnetic wave propagation,ionosphere,polynomial chaos,uncertainty,collisional magnetized cold plasma
更新于2025-09-11 14:15:04
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Large-scale gravity wave perturbations in the mesopause region above Northern Hemisphere midlatitudes during autumnal equinox: a joint study by the USU Na lidar and Whole Atmosphere Community Climate Model
摘要： To investigate gravity wave (GW) perturbations in the midlatitude mesopause region during boreal equinox, 433 h of continuous Na lidar full diurnal cycle temperature measurements in September between 2011 and 2015 are utilized to derive the monthly profiles of GW-induced temperature variance, T (cid:48)2, and the potential energy density (PED). Operating at Utah State University (42? N, 112? W), these lidar measurements reveal severe GW dissipation near 90 km, where both parameters drop to their minima (～ 20 K2 and ～ 50 m2 s?2, respectively). The study also shows that GWs with periods of 3–5 h dominate the midlatitude mesopause region during the summer–winter transition. To derive the precise temperature perturbations a new tide removal algorithm suitable for all ground-based observations is developed to de-trend the lidar temperature measurements and to isolate GW-induced perturbations. It removes the tidal perturbations completely and provides the most accurate GW perturbations for the ground-based observations. This algorithm is validated by comparing the true GW perturbations in the latest mesoscale-resolving Whole Atmosphere Community Climate Model (WACCM) with those derived from the WACCM local outputs by applying this newly developed tidal removal algorithm.
关键词： Ionosphere (wave propagation),meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides)
更新于2025-09-09 09:28:46
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Analytical Solution of Direct and Inverse Problems in the Internal Gravity Waves Studies by the Doppler Frequency Shift Method
摘要： An analytical solution of direct and inverse problems arising in the study of the internal gravity waves (IGWs) dynamic via recording of the Doppler frequency shift, is presented. The direct problem is to determine the response of the Doppler shift to IGWs in the region of the radio wave reflection point; the inverse problem is the determination of IGW parameters from data on the Doppler frequency shift. Solutions were obtained in an approximation of the isothermal ionosphere for the heights of the F-region. They are presented in a form convenient for their practical use and can have a wide range of applications, including the detection of soliton-like wave structures in the F-region of the ionosphere.
关键词： inverse problem,ionosphere,direct problem,internal gravity waves,Doppler frequency shift
更新于2025-09-09 09:28:46
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Analysis of Ionospheric GPS TEC Measurements During Total Solar Eclipse over American Region on August 21, 2017
摘要： Solar eclipse provides a unique opportunity to investigate the ionospheric response to the change in the solar flux emission towards the Earth. The variability of the ionospheric total electron content (TEC) in response to the total solar eclipse of August 21, 2017 has been studied by the analysis of dual frequency Global Positioning System (GPS) data from the University NAVSTAR Consortium (UNAVCO) established at North Carolina, USA (P779), and from the Rede Brasileira de Monitoramento Contínuo (RBMC) Amapá (APS1) station. The path of the solar obscuration passed through the North American region, also affecting the northern part of Brazil. The magnitudes of the ionospheric TEC from both monitoring stations during the eclipse are compared with those from the days immediately preceding and following it. This comparison will highlight the effects from the eclipse on the ionospheric electron density variations observed by the stations that are located over its path.
关键词： measurements,Ionosphere,Global Positioning System,solar eclipse,propagation
更新于2025-09-04 15:30:14