Radio Propagation Calculation: A Technique Using 3D Fresnel Zones for Decimeter Radio Waves on Lidar Data

2019 ◽  
Vol 61 (6) ◽  
pp. 31-43
Author(s):  
Andrej Osterman ◽  
Patrik Ritosa
Keyword(s):  
Radio Propagation ◽  
Lidar Data ◽  
Radio Waves ◽  
Fresnel Zones

Radio propagation over a sectionally homogeneous cylindrical surface

1962 ◽  
Vol 267 (1329) ◽  
pp. 183-196 ◽  
Keyword(s):  
Cylindrical Surface ◽  
Cylindrical Geometry ◽  
Radio Propagation ◽  
Two Dimensional ◽  
Electrical Characteristics ◽  
Radio Waves ◽  
Dimensional Problem

The two-dimensional problem is considered of the propagation of H -polarized radio waves over two homogeneous sections, having different electrical characteristics, of a circular cylindrical surface. Though the treatment is in the context of a cylindrical geometry, the results may be cast into a form which is equally applicable to propagation over a sphere. Expressions are developed for the field beyond the discontinuity from the source and compared with those of earlier writers, and also for the field reflected back to the source by the discontinuity and in the neighbourhood of discontinuity.

scholarly journals Study on the strength loss of Multi-hop HF Radio Propagation

2018 ◽  
Vol 175 ◽  
pp. 03012 ◽  
Author(s):  
Lingxiao Liu ◽  
Tian Lu ◽  
Mingxue Gong ◽  
Wuyu Zhang
Keyword(s):  
High Frequency ◽  
Strength Loss ◽  
Radio Propagation ◽  
Radio Waves ◽  
Long Distance ◽  
Propagation Process ◽  
Distance Information ◽  
Rugged Terrain ◽  
Radio Signals ◽  
Hf Radio Propagation

The reflections of high frequency (HF) radio waves between ionosphere and earth’s surface make long-distance information transmission possible. In this paper, the propagation process of radio signals was analyzed and the ionosphere was simplified. Considering the strength loss of signals that occurs in the travelling process and at the reflection points, two pairs of differential equations and integral equations were established to simulate the strength variations of HF radio waves and noises. A different equation of SNR was also developed, which utilized the failure threshold of signal-noise-ratio (SNR) as a criterion to evaluate the effectiveness of signals. Meanwhile, the pace of SNR attenuation was simulated when reflections happens on calm ocean, turbulent ocean, smooth terrain and rugged terrain.

scholarly journals HF radio-wave characteristic variations over China during moderate earthquake in Japan on September 5, 2018

2019 ◽  
Keyword(s):  
Radio Propagation ◽  
People’S Republic Of China ◽  
Radio Waves ◽  
People's Republic Of China ◽  
Main Mode ◽  
Radio System ◽  
Republic Of China ◽  
Moderate Earthquake ◽  
Time Variations ◽  
Propagation Paths

Urgency. The Earth's interior layers – atmosphere – ionosphere – magnetosphere (EAIM) form a one system, which is open, dynamic, and nonlinear. There are direct and reverse, positive and negative linkages among the subsystems within the EAIM system, which are currently insufficiently studied. The release of energy from a high-power source in one of the subsystems triggers the interaction among the subsystems. In this paper, a moderate earthquake of Richter magnitude M » 6.6 is considered as such a source. The aim of the paper is to describe time variations in the characteristics of the HF radio waves observed along the radio propagation paths over the People's Republic of China during the earthquake of September 5, 2018 in Japan. Techniques and Methodology. To observe the temporal variations in the characteristics of radio waves, we used the multi-frequency multiple-path coherent radio system at the Harbin Engineering University. Broadcasting stations located in the People's Republic of China, the South Korea, Japan, Russia, and Mongolia are used as transmitters. The time variations in the Doppler spectra, the Doppler shift of frequency of the main mode, and signal amplitudes were subjected to analysis. The measurements were performed in the frequency range of 5 – 10 MHz over 14 radio propagation paths extending from ~ 900 km to 1800 km and having various orientations. The Doppler spectra are calculated in 7.5-s step with the root-mean-square Doppler line error of 0.02 Hz. Results. The response of the ionosphere to a moderate earthquake was observed and studied. The delay time of the assumed response and the apparent speed of propagation of the disturbances were estimated. It was demonstrated that the seismic shock was followed by Doppler spectra spreading and the Doppler frequency shift of the main mode varying with time quasi-periodically with an ~3-min period of infrasound and an ~20 – 30-min period of atmospheric gravity wave. Conclusions: Moderate earthquakes are capable of launching disturbances in the ionosphere detectable at distances of ~1000 km from the epicenter of earthquake.

scholarly journals RadioPropa — A Modular Raytracer for In-Matter Radio Propagation

2019 ◽  
Vol 216 ◽  
pp. 03002
Author(s):  
Tobias Winchen
Keyword(s):  
Ray Tracing ◽  
Modular Design ◽  
Cosmic Ray ◽  
Index Of Refraction ◽  
Radio Propagation ◽  
Radio Waves ◽  
Lunar Rock ◽  
Runge Kutta Method ◽  
Radio Detection ◽  
Principal Design

Experiments for radio detection of UHE particles such as e.g. ARA/ARIANNA or NuMoon require detailed understanding of the propagation of radio waves in the surrounding matter. The index of refraction in e.g. polar ice or lunar rock may have a complex spatial structure that makes detailed simulations of the radio propagation necessary to design the respective experiments and analyse their data. Here, we present RadioPropa as a new modular ray tracing code that solves the eikonal equation with a Runge-Kutta method in arbitrary refractivity fields. RadioPropa is based on the cosmic ray propagation code CRPropa, which has been forked to allow efficient incorporation of the required data structures for ray tracing while retaining its modular design. This allows for the setup of versatile simulation geometries as well as the easy inclusion of additional physical effects such as e.g. partial reflection on boundary layers in the simulations. We discuss the principal design of the code as well as its performance in example applications.

scholarly journals Diffuse scattering model for human brain wave (Alpha) propagation prediction during meditation inside a temple, through ray tracing, a hypothetical study

2021 ◽  
pp. 25-29
Author(s):  
Madhulika Bharti ◽  
Priyanka Bharti ◽  
Manindra Kumar ◽  
Prashant Kumar
Keyword(s):  
Diffuse Scattering ◽  
Radio Propagation ◽  
Radio Waves ◽  
Brain Wave ◽  
Simplified Approach ◽  
Vertical Propagation ◽  
Propagation Prediction ◽  
Building Walls ◽  
The Universe ◽  
Lateral Propagation

Electromagnetic radio waves have been propagating for billions of years through the universe since the beginning of time. Electromagnetic radio wave propagation and the communication revolution it spawned, however are products of the twentieth century. Radio propagation in a particular environment is a complex, multipath phenomenon which involves several different mechanisms. According to a traditional, simplified approach, two  major urban propagation mechanisms are identified over-roof-top (ORT) or vertical propagation (VP), where one major radial path undergoes multiple diffractions on building tops, and lateral propagation (LP) where several rays reflect/diffract all vertical building walls/edges according to the geometrical Optics (GO) rules before reaching the receiver.

A Discussion on the early days of ionospheric research and the theory of electric and magnetic waves in the ionosphere and magnetosphere - Phase integral methods for studying the effect of the ionosphere on radio propagation

1975 ◽  
Vol 280 (1293) ◽  
pp. 111-130 ◽  
Keyword(s):  
Integral Method ◽  
Propagation Constant ◽  
Extraordinary Wave ◽  
Radio Propagation ◽  
Radio Waves ◽  
Exact Methods ◽  
Quartic Equation ◽  
Integral Methods ◽  
Phase Integral ◽  
Physical Principles

The phase integral method is a form of ray theory, extended to use complex values of the space coordinates. Its application to radio propagation studies was pioneered by T. L. Eckersley who showed how to use it for calculating (a) the reflexion coefficient of the ionosphere, (b) the propagation constant for radio waves guided by the Earth’s surface and by the ionosphere or troposphere, and (c) the coefficient for coupling of an ordinary and an extraordinary wave in the ionosphere. The method involves the evaluation of integrals along suitably chosen contours in complex space. It is approximate but often capable of high accuracy and often quicker to use than more exact methods. Its justification is based on the physical principles of analytic continuation and of uniform approximation. For reflexion and coupling problems in a horizontally stratified ionosphere, the contours used for the phase integrals are determined by those real or complex heights called ‘reflexion’ or ‘coupling’ points, where two roots of the Booker quartic equation are equal. The study of the behaviour of the governing equations near these points shows when failure of the phase integral method may be expected.

Radio Measurements of Coronal Magnetic Fields

1994 ◽  
Vol 144 ◽  
pp. 21-28 ◽  
Author(s):  
G. B. Gelfreikh
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Solar Corona ◽  
Active Regions ◽  
High Sensitivity ◽  
Coronal Magnetic Field ◽  
Transverse Magnetic ◽  
Radio Sources ◽  
Radio Waves ◽  
Solar Active Regions

AbstractA review of methods of measuring magnetic fields in the solar corona using spectral-polarization observations at microwaves with high spatial resolution is presented. The methods are based on the theory of thermal bremsstrahlung, thermal cyclotron emission, propagation of radio waves in quasi-transverse magnetic field and Faraday rotation of the plane of polarization. The most explicit program of measurements of magnetic fields in the atmosphere of solar active regions has been carried out using radio observations performed on the large reflector radio telescope of the Russian Academy of Sciences — RATAN-600. This proved possible due to good wavelength coverage, multichannel spectrographs observations and high sensitivity to polarization of the instrument. Besides direct measurements of the strength of the magnetic fields in some cases the peculiar parameters of radio sources, such as very steep spectra and high brightness temperatures provide some information on a very complicated local structure of the coronal magnetic field. Of special interest are the results found from combined RATAN-600 and large antennas of aperture synthesis (VLA and WSRT), the latter giving more detailed information on twodimensional structure of radio sources. The bulk of the data obtained allows us to investigate themagnetospheresof the solar active regions as the space in the solar corona where the structures and physical processes are controlled both by the photospheric/underphotospheric currents and surrounding “quiet” corona.

The High-Latitude Ionosphere and its Effects on Radio Propagation

2002 ◽  
Author(s):  
R. D. Hunsucker ◽  
J. K. Hargreaves
Keyword(s):  
High Latitude ◽  
Radio Propagation ◽  
High Latitude Ionosphere

Radio Waves Kill Insect Pests

1933 ◽  
Vol 148 (5) ◽  
pp. 272-273 ◽  
Author(s):  
J. H. Davis
Keyword(s):  
Insect Pests ◽  
Radio Waves

Small-area characterisation of UHF urban and suburban mobile radio propagation

1982 ◽  
Vol 129 (2) ◽  
pp. 102 ◽  
Author(s):  
A.S. Bajwa ◽  
J.D. Parsons
Keyword(s):  
Small Area ◽  
Mobile Radio ◽  
Radio Propagation
Sign in / Sign up

Export Citation Format

Share Document