VLF – RECORDER FOR THE STUDY OF NATURAL RADIO EMISSION

Empirical Model of Radio Wave Propagation in the Presence of Vegetation inside Greenhouses Using Regularized Regressions

Sensors ◽

10.3390/s20226621 ◽

2020 ◽

Vol 20 (22) ◽

pp. 6621

Author(s):

Dora Cama-Pinto ◽

Miguel Damas ◽

Juan Antonio Holgado-Terriza ◽

Francisco Manuel Arrabal-Campos ◽

Francisco Gómez-Mula ◽

...

Keyword(s):

Wave Propagation ◽

Radio Wave ◽

Empirical Model ◽

Precision Agriculture ◽

Wave Attenuation ◽

Multipath Propagation ◽

Field Tests ◽

Radio Wave Propagation ◽

Radio Waves ◽

Vegetation Height

Spain is Europe’s leading exporter of tomatoes harvested in greenhouses. The production of tomatoes should be kept and increased, supported by precision agriculture to meet food and commercial demand. The wireless sensor network (WSN) has demonstrated to be a tool to provide farmers with useful information on the state of their plantations due to its practical deployment. However, in order to measure its deployment within a crop, it is necessary to know the communication coverage of the nodes that make up the network. The multipath propagation of radio waves between the transceivers of the WSN nodes inside a greenhouse is degraded and attenuated by the intricate complex of stems, branches, leaf twigs, and fruits, all randomly oriented, that block the line of sight, consequently generating a signal power loss as the distance increases. Although the COST235 (European Cooperation in Science and Technology - COST), ITU-R (International Telecommunications Union—Radiocommunication Sector), FITU-R (Fitted ITU-R), and Weisbberger models provide an explanation of the radio wave propagation in the presence of vegetation in the 2.4 GHz ICM band, some significant discrepancies were found when they are applied to field tests with tomato greenhouses. In this paper, a novel method is proposed for determining an empirical model of radio wave attenuation for vegetation in the 2.4 GHz band, which includes the vegetation height as a parameter in addition to the distance between transceivers of WNS nodes. The empirical attenuation model was obtained applying regularized regressions with a multiparametric equation using experimental signal RSSI measurements achieved by our own RSSI measurement system for our field tests in four plantations. The evaluation parameters gave 0.948 for R2, 0.946 for R2 Adj considering 5th grade polynomial (20 parameters), and 0.942 for R2, and 0.940 for R2 Adj when a reduction of parameters was applied using the cross validation (15 parameters). These results verify the rationality and reliability of the empirical model. Finally, the model was validated considering experimental data from other plantations, reaching similar results to our proposed model.

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Forecasting characteristics of propagation of decameter radio waves using the global ionosphere and plasmasphere model

Solnechno-Zemnaya Fizika ◽

10.12737/10452 ◽

2015 ◽

Vol 1 (3) ◽

pp. 49-54 ◽

Cited By ~ 4

Author(s):

Сергей Пономарчук ◽

Sergey Ponomarchuk ◽

Галина Котович ◽

Galina Kotovich ◽

Елена Романова ◽

...

Keyword(s):

Wave Propagation ◽

Radio Wave ◽

Normal Wave ◽

Middle Latitude ◽

Radio Wave Propagation ◽

Radio Waves ◽

Radio Communication ◽

Iri Model ◽

Decameter Radio ◽

Minimum Number

We present the forecast results of maximal usable frequencies for mid-latitude paths on the base of complex We present the results of forecasting maximum usable frequencies (MUF) on middle-latitude paths on the basis of complex algorithm including modules of the ionosphere and plasmasphere global model (IPGM) and the model of radio wave propagation. The computation of propagation characteristics for decameter radio waves is carried out within the framework of normal wave technique. IPGM developed in ISTP SB RAS enables to compute electron concentration profiles and effective frequency of collisions using minimum number of input data and taking into account physical processes in the Earth’s upper atmosphere. To estimate the efficiency of using IPGM in long-term forecast of radio wave propagation we computed MUF for radio communication in various heliogeophysical conditions. To obtain precision characteristics of MUF forecast we used experimental data of oblique sounding on Magadan–Irkutsk, Khabarovsk–Irkutsk, Norilsk–Irkutsk paths. The paths are equipped with modern ionosphere diagnostic hardware for oblique sounding by continuous chirp signal. We also compared results of MUF forecast using IPGM with computations carried out according IRI model.

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Characteristics of the electromagnetic environment created by radiations of user equipment of ...4G/5G/6G cellular (mobile) communications in buildings

Doklady BGUIR ◽

10.35596/1729-7648-2021-19-6-42-50 ◽

2021 ◽

Vol 19 (6) ◽

pp. 42-50

Author(s):

V. I. Mordachev

Keyword(s):

Wave Propagation ◽

Radio Wave ◽

Flux Density ◽

Mobile Communications ◽

Electromagnetic Compatibility ◽

Radio Wave Propagation ◽

Radio Waves ◽

Interior Space ◽

Power Flux ◽

Near Zone

The goal of the work is to substantiate the technique for assessing the intensity of electromagnetic background generated by the set of radiating user devices of mobile communications in multi-storey buildings. For known empirical models of radio wave propagation in buildings, expressions are obtained for the probability distribution density and expectation of the power flux density of electromagnetic fields generated inside building by these sources from various parts of the building's interior space: from the near zone with radio wave propagation conditions similar to free space; and from the far zone, for which, along with intense attenuation of radio waves due to internal obstacles, a «quasi-waveguide» propagation of radio waves along corridors and industrial premises is also possible in certain directions. Relationships are obtained for the average levels of individual components of the electromagnetic background, determined as scalar sums of power flux density values of the fields generated by the sets of radiating devices of both the near zone and the far zone as a whole or its individual parts, characterized by different conditions of radio wave propagation. A method is proposed for assessing the electromagnetic background inside buildings based on approximation of sections of the inner surface of the premises in which the observation point is located, and the outer surface of the building, in the inner space of which radiation sources are randomly distributed, by the corresponding sections of the inner and outer spherical surfaces that are the subtend areas of the corresponding solid angles, in space elements of which a different spatial densities and radiation powers of sources and different conditions of radio wave propagation are possible. The results can be used to analyze the electromagnetic ecology of habitat and the electromagnetic safety of population at the full-scale implementation of 4G/5G/6G mobile communications, as well as to analyze the electromagnetic compatibility of systems using frequency bands for mobile communications on a primary and secondary basis.

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Research on Fast Algorithm of Radio Wave Propagation in Low-Lossy Obstacles Environment

International Journal of Antennas and Propagation ◽

10.1155/2021/5519586 ◽

2021 ◽

Vol 2021 ◽

pp. 1-13

Author(s):

An-qi Li ◽

Cheng-you Yin ◽

Qian-qian Zhang ◽

Yong-ji Gan

Keyword(s):

Wave Propagation ◽

Radio Wave ◽

Radio Wave Propagation ◽

Radio Waves ◽

Impedance Boundary ◽

Complex Image ◽

Surface Impedance Boundary Conditions ◽

Decomposition Principle ◽

Good Agreement ◽

Discrete Complex

To predict the propagation of radio waves in the environment of dielectric ground and dielectric obstacles, a new two-way parabolic equation (2W-PE) method based on the domain decomposition principle and surface impedance boundary conditions (SIBC) is proposed. First, we decompose the obstacle area into different subdomains and derive the SIBC in each subdomain in detail; then, the discrete hybrid Fourier transform (DMFT) in the upper subdomain and finite difference (FD) algorithm in the lower subdomain is used to solve 2W-PE combined with SIBC, respectively. After that, we explain the algorithm steps in the process of calculating the total field, compared with the traditional 2W-PE, and then finally introduce the method of moments (MoM) combined with the enhanced discrete complex image (E-DCIM) method for accuracy verification of the new 2W-PE algorithm. The simulation results show that no matter how the obstacle medium parameters change, the results of 2W-PE method proposed in this paper and MoM are always in good agreement, which proves the accuracy of 2W-PE and its superiority in speed. Therefore, this paper provides a reliable and efficient method for solving the problem of radio wave propagation in the presence of obstacles, especially in the case of low-lossy obstacles.

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VLF LIGHTNING DIRECTION FINDER

Вестник КРАУНЦ. Физико-математические науки ◽

10.26117/2079-6641-2019-27-2-95-104 ◽

2019 ◽

pp. 95-104

Author(s):

Г.И. Дружин ◽

В.М. Пухов ◽

Д.В. Санников ◽

Е.И. Малкин

Keyword(s):

Electromagnetic Field ◽

Wave Propagation ◽

Electromagnetic Radiation ◽

Radio Wave ◽

Real Time ◽

Magnetic Components ◽

Direction Finder ◽

Academy Of Sciences ◽

Far Eastern ◽

Cosmophysical Research

Для исследования мощных электромагнитных излучений от гроз в Институте космофизических исследований и распространения радиоволн ДВО РАН создан ОНЧ пеленгатор, способный записывать сигналы электрических и магнитных компонент электромагнитного поля, определять направления прихода излучений в реальном времени. С помощью ОНЧпеленгатора на Камчатке исследованы эффекты, связанные с грозовыми источниками. For the study of powerful electromagnetic radiation from thunderstorms, a VLF direction finder was created at the Institute of Cosmophysical Research and Radio Wave Propagation of the Far Eastern Branch of the Russian Academy of Sciences, capable of recording signals of electrical and magnetic components of the electromagnetic field, and determining the direction of radiation arrival in real time. With the help of VLF direction finder in Kamchatka, the effects associated with thunderstorm sources are investigated.

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Forecasting characteristics of propagation of decameter radio waves using the global ionosphere and plasmasphere model

Solnechno-Zemnaya Fizika ◽

10.12737/11452 ◽

2015 ◽

Vol 1 (3) ◽

pp. 49-54

Author(s):

Романова ◽

Elena Romanova ◽

Котович ◽

Galina Kotovich ◽

Пономарчук ◽

...

Keyword(s):

Wave Propagation ◽

Radio Wave ◽

Normal Wave ◽

Middle Latitude ◽

Radio Wave Propagation ◽

Radio Waves ◽

Radio Communication ◽

Iri Model ◽

Decameter Radio ◽

Minimum Number

We present the forecast results of maximal usable frequencies for mid-latitude paths on the base of complex We present the results of forecasting maximum usable frequencies (MUF) on middle-latitude paths on the basis of complex algorithm including modules of the ionosphere and plasmasphere global model (IPGM) and the model of radio wave propagation. The computation of propagation characteristics for decameter radio waves is carried out within the framework of normal wave technique. IPGM developed in ISTP SB RAS enables to compute electron concentration profiles and effective frequency of collisions using minimum number of input data and taking into account physical processes in the Earth’s upper atmosphere. To estimate the efficiency of using IPGM in long-term forecast of radio wave propagation we computed MUF for radio communication in various heliogeophysical conditions. To obtain precision characteristics of MUF forecast we used experimental data of oblique sounding on Magadan–Irkutsk, Khabarovsk–Irkutsk, Norilsk–Irkutsk paths. The paths are equipped with modern ionosphere diagnostic hardware for oblique sounding by continuous chirp signal. We also compared results of MUF forecast using IPGM with computations carried out according IRI model.

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