Log in

Relevant bibliographies by topics / VLF propagation / Journal articles

To see the other types of publications on this topic, follow the link: VLF propagation.

Journal articles on the topic 'VLF propagation'

Author: Grafiati

Published: 5 June 2025

Last updated: 2 August 2025

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'VLF propagation.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Schmitter, E. D. "Remote sensing planetary waves in the midlatitude mesosphere using low frequency transmitter signals." Annales Geophysicae 29, no. 7 (2011): 1287–93. http://dx.doi.org/10.5194/angeo-29-1287-2011.

Full text

Abstract:

Abstract. Very low and low radio frequency (VLF/LF) propagation responds sensitively to the electron density distribution in the lower ionosphere (upper mesosphere). Whereas propagation paths crossing subpolar and polar regions are frequently affected by forcing from above by particle precipitations, mid- and lowlatitude paths let forcing from below be more prominent. Our observations (2009–2011) show, that the low frequency propagation conditions along the midlatitude path from Sicily to Germany (52° N 8° E) using the NSY 45.9 kHz transmitter (37° N 14° E) prove to be a good proxy of mesosphe

APA, Harvard, Vancouver, ISO, and other styles

2

Li, Guang Ming, Cui Hua Liu, and Guang You Cai. "Propagation Effectiveness Prediction and Simulation of VLF Communication." Applied Mechanics and Materials 380-384 (August 2013): 3487–92. http://dx.doi.org/10.4028/www.scientific.net/amm.380-384.3487.

Full text

Abstract:

The vlf radio wave propagation is usually treated as a waveguide problem. It should be noted that many of the parameters that describe the boundaries of the earth-ionosphere waveguide are not known with great accuracy over all regions and times. In order to know the effect of underwater platform receiving in corresponding region and time, this paper makes use of the waveguide mode theory to predict the propagation effectiveness of vlf radio, offers the service of propagation environment for the system to adjust the variable parameters or abstain from propagation attenuation, makes the system p

APA, Harvard, Vancouver, ISO, and other styles

3

Gu, Xudong, Juan Yi, Shiwei Wang, et al. "Comparison of VLF Signal Responses to Solar Flares along Daytime and Nighttime Propagation Paths." Remote Sensing 15, no. 4 (2023): 1018. http://dx.doi.org/10.3390/rs15041018.

Full text

Abstract:

Solar flares have a severe impact on the near-earth space environment, during which the VLF signals observed by the ground-based instrument exhibit abnormal changes. However, the similarity and differences of VLF signal responses to solar flares over daytime and nighttime propagation paths are still unclear. Previous magnetograph measurements suggest that solar flares can also influence the dark hemisphere by the induction currents caused by the change in the ionospheric electrical conductivity of the sunlit hemisphere. To examine these effects, we have analyzed the solar flare effects on VLF

APA, Harvard, Vancouver, ISO, and other styles

4

Hutchins, M. L., Abram R. Jacobson, Robert H. Holzworth, and James B. Brundell. "Azimuthal dependence of VLF propagation." Journal of Geophysical Research: Space Physics 118, no. 9 (2013): 5808–12. http://dx.doi.org/10.1002/jgra.50533.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Cheng, Wen, Wei Xu, Xudong Gu, et al. "A Comparative Study of VLF Transmitter Signal Measurements and Simulations during Two Solar Eclipse Events." Remote Sensing 15, no. 12 (2023): 3025. http://dx.doi.org/10.3390/rs15123025.

Full text

Abstract:

To monitor the Very-Low-Frequency (VLF) environment, a VLF detection system has been installed in Suizhou, China, a location with the longitude almost identical to that of the NWC transmitter in Australia. In the years 2019 and 2020, two solar eclipses crossed the NWC–Suizhou path at different locations. Each solar eclipse event represents a naturally occurring controlled experiment, but these two events are unique in that similar levels of electron density variation occurred at different locations along the VLF propagation path. Therefore, we conducted a comparative study using the VLF measur

APA, Harvard, Vancouver, ISO, and other styles

6

Zhou, Jian Ping, and Guang Ming Li. "Research on the Frequency Spectrum Management Method of VLF Based on the Propagation Prediction Technology." Applied Mechanics and Materials 543-547 (March 2014): 2180–83. http://dx.doi.org/10.4028/www.scientific.net/amm.543-547.2180.

Full text

Abstract:

VLF communication is one of the most effective means to command underwater platform. The spectrum resource of vlf communication is limited, so it is very important for enhance the reliability of vlf communication to strengthen the vlf communication spectrum management. It makes use of the well prediction of the vlf frequency band, to establish the signal field predicting model and atmospheric noise statistics predicting model respectively, predicts the field of signal and noise level, and then calculated the signal-to-noise ratio (SNR). According to the SNR distribution we can determine the re

APA, Harvard, Vancouver, ISO, and other styles

7

Wang, Shiwei, Ruoxian Zhou, Xudong Gu, et al. "Examining the Capability of the VLF Technique for Nowcasting Solar Flares Based on Ground Measurements in Antarctica." Remote Sensing 16, no. 12 (2024): 2092. http://dx.doi.org/10.3390/rs16122092.

Full text

Abstract:

Measurements of Very-Low-Frequency (VLF) transmitter signals have been widely used to investigate the effects of various space weather events on the D-region ionosphere, including nowcasting solar flares. Previous studies have established a method to nowcast solar flares using VLF measurements, but only using measurements from dayside propagation paths, and there remains limited focus on day–night mixed paths, which are important for method applicability. Between March and May of 2022, the Sun erupted a total of 56 M-class and 6 X-class solar flares, all of which were well captured by our VLF

APA, Harvard, Vancouver, ISO, and other styles

8

Schmitter, E. D. "Remote sensing and modeling of lightning caused long recovery events within the lower ionosphere using VLF/LF radio wave propagation." Advances in Radio Science 12 (November 11, 2014): 241–50. http://dx.doi.org/10.5194/ars-12-241-2014.

Full text

Abstract:

Abstract. On the 4 November 2012 at 3:04:27 UT a strong lightning in the midst of the North Sea affected the propagation conditions of VLF/LF transmitter radio signals from NRK (Iceland, 37.5 kHz) and GBZ (UK, 19.58 kHz) received at 5246° N 8° E (NW Germany). The amplitude and phase dips show a recovery time of 6–12 min pointing to a LOng Recovery Early VLF (LORE) event. Clear assignment of the causative return stroke in space and time was possible with data from the WWLLN (Worldwide Lightning Location Network). Based on a return stroke current model the electric field is calculated and an exc

APA, Harvard, Vancouver, ISO, and other styles

9

Nunn, D., M. A. Clilverd, C. J. Rodger, and N. R. Thomson. "The impact of PMSE and NLC particles on VLF propagation." Annales Geophysicae 22, no. 5 (2004): 1563–74. http://dx.doi.org/10.5194/angeo-22-1563-2004.

Full text

Abstract:

Abstract. PMSE or Polar Mesosphere Summer Echoes are a well-known phenomenon in the summer northern polar regions, in which anomalous VHF/UHF radar echoes are returned from heights ~85km. Noctilucent clouds and electron density biteouts are two phenomena that sometimes occur together with PMSE. Electron density biteouts are electron density depletion layers of up to 90%, which may be several kms thick. Using the NOSC Modefndr code based on Wait's modal theory for subionospheric propagation, we calculate the shifts in received VLF amplitude and phase that occur as a result of electron density b

APA, Harvard, Vancouver, ISO, and other styles

10

Roy, Jean. "On: “Effect of temporal and spatial variations of the primary signal on VLF total‐field surveys” by M. A. Vallee, M. Chouteau, and G. J. Palacky (January 1992 GEOPHYSICS, p. 97‐105)." GEOPHYSICS 58, no. 5 (1993): 756. http://dx.doi.org/10.1190/1.1443461.

Full text

Abstract:

Vallee et al. (1992) remark on the sensitivity of airborne ratio measuring VLF instruments to platform attitude stability. The authors also remind the users of VLF total field amplitude data, as produced by instruments such as the Herz TOTEM, of two problems associated with this type of data: spatial and temporal fluctuations of the VLF primary field. They recommend the use of a dense network of VLF monitoring stations and numerical modeling of field propagation to cope with these problems. These two recommendations are briefly discussed here and one alternative recommendation is made.

APA, Harvard, Vancouver, ISO, and other styles

11

Schwingenschuh, K., G. Prattes, B. P. Besser, et al. "The Graz seismo-electromagnetic VLF facility." Natural Hazards and Earth System Sciences 11, no. 4 (2011): 1121–27. http://dx.doi.org/10.5194/nhess-11-1121-2011.

Full text

Abstract:

Abstract. In this paper we describe the Graz seismo-electromagnetic very low frequency (VLF) facility, as part of the European VLF receiver network, together with the scientific objectives and results from two years operation. After a brief technical summary of the present system – with heritage from a predecessor facility – i.e. hardware, software, operational modes and environmental influences, we discuss results from statistical data and scientific events related to terrestrial VLF propagation over Europe.

APA, Harvard, Vancouver, ISO, and other styles

12

Pal, Sujay, Yasuhide Hobara, Alexander Shvets, Peter Wilhelm Schnoor, Masashi Hayakawa, and Oleksandr Koloskov. "First Detection of Global Ionospheric Disturbances Associated with the Most Powerful Gamma Ray Burst GRB221009A." Atmosphere 14, no. 2 (2023): 217. http://dx.doi.org/10.3390/atmos14020217.

Full text

Abstract:

We present the first report of global ionospheric disturbances due to the most powerful Gamma Ray Burst GRB221009A occurred on 9 October 2022. Very Low Frequency (VLF) and Low Frequency (LF) sub-ionospheric radio signals are used to diagnose the effect of the GRB on the lower ionosphere. Both daytime and nighttime effects are analyzed in VLF and LF bands. The magnitude of VLF signal perturbations varied with the propagation condition (day/night), path length, and frequency of the signal. The recovery times for the VLF/LF signals to get back to their pre-GRB levels varied from 2–60 min. Radio s

APA, Harvard, Vancouver, ISO, and other styles

13

Grubor, Davorka, D. Sulic, and V. Zigman. "Influence of solar X-ray flares on the earth-ionosphere waveguide." Serbian Astronomical Journal, no. 171 (2005): 29–35. http://dx.doi.org/10.2298/saj0571029g.

Full text

Abstract:

A simultaneous analysis of solar are X-ray irradiance and VLF signal amplitude on the GQD/22.1 kHz trace was carried out. Solar are data were taken from GOES 12 satellite listings. The VLF amplitude data were recorded by means of the AbsPAL (Absolute Phase and Amplitude Logger) at the Institute of Physics, Belgrade, Serbia. It was found that solar are events from class C to class X affect the VLF signal amplitude in various ways and can be classified according to the type of effect produced in the Earth-ionosphere waveguide on the VLF propagation.

APA, Harvard, Vancouver, ISO, and other styles

14

Zhou, K. P., Y. T. Niu, W. N. Liu, et al. "Study and Analysis of a Multilayer Multipair Electret-Based Thin-Film Mechanical Antenna." International Journal of Antennas and Propagation 2021 (November 26, 2021): 1–18. http://dx.doi.org/10.1155/2021/3646425.

Full text

Abstract:

Very low-frequency (VLF) and ultralow-frequency (ULF) electromagnetic waves have the advantage of high penetration and low propagation loss in wireless communication systems and are mainly used for underwater and underground communications, as well as for earthquake and lightning forecasting. At present, VLF and ULF antennas are mostly bulky and require hundreds of antennas and more to be set up, which is costly and inefficient. In this paper, we propose to generate VLF and ULF signals by rotating a multilayer multipair electret thin-film electret driven by an excitation device, which improves

APA, Harvard, Vancouver, ISO, and other styles

15

Huang, Kui, Qi Xiao, Juan Chen, and Mian Dong. "A Study on the Electromagnetic Characteristics of Very-Low- Frequency Waves in the Ionosphere Based on FDTD." Electronics 14, no. 8 (2025): 1545. https://doi.org/10.3390/electronics14081545.

Full text

Abstract:

Very-low-frequency electromagnetic waves have low propagation loss, slow attenuation, a stable phase and amplitude in the Earth ionosphere waveguide cavity, and are widely used in VLF communication and navigation, ionospheric heating, global lightning distribution inversion, and other fields. Studying the transmission characteristics of very-low-frequency (VLF) signals in the ionosphere is of great significance in spaceborne VLF communication technology. The existing research on ionospheric transmission characteristics using the finite-difference time domain (FDTD) algorithm is mostly based on

APA, Harvard, Vancouver, ISO, and other styles

16

Sereno, T. J., W. E. Farrell, J. A. Orcutt, and R. G. Adair. "VLF propagation loss to a buried seismometer." IEEE Journal of Oceanic Engineering 13, no. 4 (1988): 254–62. http://dx.doi.org/10.1109/48.9238.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Shubova, R. S., M. D. Sopel'nikov, and N. A. Knyazeva. "Anomalies in vlf propagation and possible interpretations." Radiophysics and Quantum Electronics 28, no. 5 (1985): 396–400. http://dx.doi.org/10.1007/bf01034835.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Akhmetov, O. I., I. V. Mingalev, O. V. Mingalev, V. B. Belakhovsky, and Z. V. Suvorova. "Features of Radio Signal Propagation in the VLF Range at High Latitudes during Solar Proton Events." Геомагнетизм и аэрономия 63, no. 4 (2023): 411–21. http://dx.doi.org/10.31857/s0016794022600545.

Full text

Abstract:

In this paper, we study the amplitude and phase characteristics of VLF signals of an anthropogenicorigin during solar proton events using the methods of a computational experiment. We consider the events ofOctober 30, 2003 and January 23, 2012. Electron density profiles are plotted using data from the VHF EISCATincoherent scatter radar located in Tromsø, Norway. Based on the processed data of computational experiments,that under the conditions of solar proton events, mainly amplitude distortions of VLF signals wereshown to be observed while there is a frequency dependence of the magnitude of d

APA, Harvard, Vancouver, ISO, and other styles

19

Sulic, D. M., and V. A. Sreckovic. "A comparative study of measured amplitude and phase perturbations of VLF and LF radio signals induced by solar flares." Serbian Astronomical Journal, no. 188 (2014): 45–54. http://dx.doi.org/10.2298/saj1488045s.

Full text

Abstract:

Very Low Frequency (VLF) and Low Frequency (LF) signal perturbations were examined to study ionospheric disturbances induced by solar X-ray flares in order to understand processes involved in propagation of VLF/LF radio signals over short paths and to estimate specific characteristics of each short path. The receiver at the Belgrade station is constantly monitoring the amplitude and phase of a coherent and subionospherically propagating LF signal operated in Sicily NSC at 45.90 kHz, and a VLF signal operated in Isola di Tavolara ICV at 20.27 kHz, with the great circle distances of 953 km and 9

APA, Harvard, Vancouver, ISO, and other styles

20

Politis, Dimitrios Z., Stelios M. Potirakis, Yiannis Contoyiannis, et al. "Lower-ionosphere anomalies prior to strong earthquakes that occurred in north-central mainland Greece on March 2021 as revealed by multi-method analysis of VLF sub-ionospheric propagation data." Annals of Geophysics 66, no. 6 (2023): SE645. http://dx.doi.org/10.4401/ag-8986.

Full text

Abstract:

In this work we present the multi-method analysis of very low frequency (VLF) data, acquired by the radio receiver with call name UWA, located in Athens (Greece), in the University of West Attica, focusing on two strong ( ) earthquakes (EQs) that occurred in north-central mainland Greece sequentially, on 3 and 4 March 2021, with very close epicenters. Specifically, we used the data acquired from seven VLF transmitters located in Europe, North/North-West to UWA, and their propagation paths include the specific EQs epicenters. We analyzed these data using multiple analysis methods in order to in

APA, Harvard, Vancouver, ISO, and other styles

21

Lefeuvre, F., J. L. Pinçon, and M. Parrot. "Midlatitude propagation of VLF to MF waves through nighttime ionosphere above powerful VLF transmitters." Journal of Geophysical Research: Space Physics 118, no. 3 (2013): 1210–19. http://dx.doi.org/10.1002/jgra.50177.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Tolstoy, A., and T. J. Rosenberg. "A quasi three-dimensional propagation model for subionospherically propagating VLF radio waves." Radio Science 20, no. 3 (1985): 535–38. http://dx.doi.org/10.1029/rs020i003p00535.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Дружин, Г. И., В. М. Пухов, Д. В. Санников, and Е. И. Малкин. "VLF LIGHTNING DIRECTION FINDER." Вестник КРАУНЦ. Физико-математические науки, no. 2 (July 20, 2019): 95–104. http://dx.doi.org/10.26117/2079-6641-2019-27-2-95-104.

Full text

Abstract:

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 Br

APA, Harvard, Vancouver, ISO, and other styles

24

Chang, S. S., B. B. Ni, J. Bortnik, et al. "Resonant scattering of energetic electrons in the plasmasphere by monotonic whistler-mode waves artificially generated by ionospheric modification." Annales Geophysicae 32, no. 5 (2014): 507–18. http://dx.doi.org/10.5194/angeo-32-507-2014.

Full text

Abstract:

Abstract. Modulated high-frequency (HF) heating of the ionosphere provides a feasible means of artificially generating extremely low-frequency (ELF)/very low-frequency (VLF) whistler waves, which can leak into the inner magnetosphere and contribute to resonant interactions with high-energy electrons in the plasmasphere. By ray tracing the magnetospheric propagation of ELF/VLF emissions artificially generated at low-invariant latitudes, we evaluate the relativistic electron resonant energies along the ray paths and show that propagating artificial ELF/VLF waves can resonate with electrons from

APA, Harvard, Vancouver, ISO, and other styles

25

Barghi, W., M. R. Delavar, M. Shahabadi, M. Zare, S. A. EslamiNezhad, and H. Bayat. "EARTHQUAKE PREDICTION EVALUATION BASED ON VLF DATA USING A NOVEL INTERSECTION-UNION METHOD." ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences V-4-2021 (June 17, 2021): 25–32. http://dx.doi.org/10.5194/isprs-annals-v-4-2021-25-2021.

Full text

Abstract:

Abstract. Electromagnetic phenomena, especially those in the Very Low Frequency/Low Frequency (VLF/LF) bands are promising for short-term earthquake prediction. Seismo-ionospheric perturbations cause a variety of changes in different receiver-transmitter VLF/LF signal paths. Therefore, independent and simultaneous observations at different points thus in different VLF/LF signal propagation paths are necessary to better predict the earthquake. Most of the previous research on VLF data have been based on one path or limited number of paths which examined perturbations in the time domain and less

APA, Harvard, Vancouver, ISO, and other styles

26

Stephen, R., and M. Holzrichter. "VLF pulse propagation in range‐dependent geoacoustic waveguides." Journal of the Acoustical Society of America 80, S1 (1986): S53. http://dx.doi.org/10.1121/1.2023852.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Malkotsis, Filopimin, Dimitrios Z. Politis, Dionisis Dimakos, and Stelios M. Potirakis. "An Amateur-Radio-Based Open-Source (HW/SW) VLF/LF Receiver for Lower Ionosphere Monitoring, Examples of Identified Perturbations." Foundations 2, no. 3 (2022): 639–63. http://dx.doi.org/10.3390/foundations2030044.

Full text

Abstract:

The ground-based monitoring of the lower ionosphere by studying the perturbations of the subionospheric propagation of very-low-frequency/low-frequency (VLF/LF) signals is important in the research of a wide variety of geophysical and Sun/space extreme phenomena. Such perturbations are identified as anomalies in the signal received from the VLF/LF transmitters operating worldwide for military purposes, time code broadcasting, etc. Especially for the study of local ionosphere-influencing phenomena, such as earthquakes, volcanoes, typhoons, etc., the monitoring of several subionospheric propagat

APA, Harvard, Vancouver, ISO, and other styles

28

Tatsuta, K., Y. Hobara, S. Pal, and M. Balikhin. "Sub-ionospheric VLF signal anomaly due to geomagnetic storms: a statistical study." Annales Geophysicae 33, no. 11 (2015): 1457–67. http://dx.doi.org/10.5194/angeo-33-1457-2015.

Full text

Abstract:

Abstract. We investigate quantitatively the effect of geomagnetic storms on the sub-ionospheric VLF/LF (Very Low Frequency/Low Frequency) propagations for different latitudes based on 2-year nighttime data from Japanese VLF/LF observation network. Three statistical parameters such as average signal amplitude, variability of the signal amplitude, and nighttime fluctuation were calculated daily for 2 years for 16–21 independent VLF/LF transmitter–receiver propagation paths consisting of three transmitters and seven receiving stations. These propagation paths are suitable to simultaneously study

APA, Harvard, Vancouver, ISO, and other styles

29

Ray, S., and S. K. Chakrabarti. "A study of the behavior of the terminator time shifts using multiple VLF propagation paths during the Pakistan earthquake (<i>M</i> = 7.2) of 18 January 2011." Natural Hazards and Earth System Sciences 13, no. 6 (2013): 1501–6. http://dx.doi.org/10.5194/nhess-13-1501-2013.

Full text

Abstract:

Abstract. On 18 January 2011, at 20:23 UTC, an earthquake of magnitude 7.2 occurred in southwestern Pakistan (latitude 28°44' N, longitude 63°56' E) at a depth of 68 km. We present the results of the analysis of very low frequency (VLF) radio signals, received at three stations located in India. We analyze the VLF signals around this earthquake day and look for possible precursory effects of this earthquake. For our analysis, we use four different VLF propagation paths. These propagation paths are DHO–IERC (Sitapur), VTX–Pune, VTX–ICSP (Indian Centre for Space Physics, Kolkata) and NWC–IERC. W

APA, Harvard, Vancouver, ISO, and other styles

30

Hou, Wenhao, Qilin Zhang, Jinbo Zhang, Lei Wang, and Yuan Shen. "A New Approximate Method for Lightning-Radiated ELF/VLF Ground Wave Propagation over Intermediate Ranges." International Journal of Antennas and Propagation 2018 (July 11, 2018): 1–10. http://dx.doi.org/10.1155/2018/9353294.

Full text

Abstract:

A new approximate method for lightning-radiated extremely low-frequency (ELF) and very low-frequency (VLF) ground wave propagation over intermediate ranges is presented in this paper. In our approximate method, the original field attenuation function is divided into two factors in frequency domain representing the propagation effect of the ground conductivity and Earth’s curvature, and both of them have clearer formulations and can more easily be calculated rather than solving a complex differential equation related to Airy functions. The comparison results show that our new approximate method

APA, Harvard, Vancouver, ISO, and other styles

31

Kasahara, Y., F. Muto, Y. Hobara, and M. Hayakawa. "The ionospheric perturbations associated with Asian earthquakes as seen from the subionospheric propagation from NWC to Japanese stations." Natural Hazards and Earth System Sciences 10, no. 3 (2010): 581–88. http://dx.doi.org/10.5194/nhess-10-581-2010.

Full text

Abstract:

Abstract. Huge five earthquakes with magnitude greater than 6.0 took place in Asia (include Philippines, Indonesia, etc.) during the period from the beginning of August 2008 to the end of Junuary 2009, and the corresponding data of subionospheric VLF propagation between the NWC transmitter (Australia, 19.8 kHz) and a few Japanese stations (distance 6~8 Mm) are examined. As the result of our analysis by means of (1) trend (average nighttime amplitude), (2) dispersion, (3) nighttime fluctuation, and (4) atmospheric gravity wave enhancement, three earthquakes from the five taking place within the

APA, Harvard, Vancouver, ISO, and other styles

32

Politis, Dimitrios Z., Stelios M. Potirakis, Yiannis F. Contoyiannis, Sagardweep Biswas, Sudipta Sasmal, and Masashi Hayakawa. "Statistical and Criticality Analysis of the Lower Ionosphere Prior to the 30 October 2020 Samos (Greece) Earthquake (M6.9), Based on VLF Electromagnetic Propagation Data as Recorded by a New VLF/LF Receiver Installed in Athens (Greece)." Entropy 23, no. 6 (2021): 676. http://dx.doi.org/10.3390/e23060676.

Full text

Abstract:

In this work we present the statistical and criticality analysis of the very low frequency (VLF) sub-ionospheric propagation data recorded by a VLF/LF radio receiver which has recently been established at the University of West Attica in Athens (Greece). We investigate a very recent, strong (M6.9), and shallow earthquake (EQ) that occurred on 30 October 2020, very close to the northern coast of the island of Samos (Greece). We focus on the reception data from two VLF transmitters, located in Turkey and Israel, on the basis that the EQ’s epicenter was located within or very close to the 5th Fre

APA, Harvard, Vancouver, ISO, and other styles

33

Nwankwo, Victor U. J., William Denig, Sandip K. Chakrabarti, et al. "Diagnostic study of geomagnetic storm-induced ionospheric changes over very low-frequency signal propagation paths in the mid-latitude D region." Annales Geophysicae 40, no. 4 (2022): 433–61. http://dx.doi.org/10.5194/angeo-40-433-2022.

Full text

Abstract:

Abstract. We performed a diagnostic study of geomagnetic storm-induced disturbances that are coupled to the mid-latitude D region by quantifying the propagation characteristics of very low-frequency (VLF) radio signals from transmitters located in Cumbria, UK (call sign GQD), and Rhauderfehn, Germany (DHO), and received in southern France (A118). We characterised the diurnal VLF amplitudes from two propagation paths into five metrics, namely the mean amplitude before sunrise (MBSR), the midday amplitude peak (MDP), the mean amplitude after sunset (MASS), the sunrise terminator (SRT) and the su

APA, Harvard, Vancouver, ISO, and other styles

34

Juhl, B., and R. A. Treumann. "VLF emission stimulated by parallel electric fields." Journal of Plasma Physics 34, no. 1 (1985): 47–66. http://dx.doi.org/10.1017/s0022377800002671.

Full text

Abstract:

We study the influence of a weak quasi-static parallel electric field on the stability of electromagnetic plasma waves. Using an operator calculus to solve the Boltzmann-Maxwell equations we derive a dispersion relation for the electromagnetic waves. Assuming that the electrons have a loss-cone distribution, the real frequency of waves in the whistler band is not changed by the presence of the electric field. Resonant interaction damps the HF waves for propagation parallel to the electric field. In the case of opposite propagation, a new HF excitation is found at frequencies ω ≲ ωce The width

APA, Harvard, Vancouver, ISO, and other styles

35

Tomko, A. A., and T. Hepner. "Worldwide monitoring of VLF-LF propagation and atmospheric noise." Radio Science 36, no. 2 (2001): 363–69. http://dx.doi.org/10.1029/1999rs002402.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Ralchenko, Maxim, Mike Roper, Claire Samson, and Markus Svilans. "Near-Field VLF Electromagnetic Signal Propagation in Multistory Buildings." IEEE Transactions on Antennas and Propagation 66, no. 2 (2018): 848–56. http://dx.doi.org/10.1109/tap.2017.2783321.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Lehtinen, Nikolai G., and Umran S. Inan. "Full-wave modeling of transionospheric propagation of VLF waves." Geophysical Research Letters 36, no. 3 (2009): n/a. http://dx.doi.org/10.1029/2008gl036535.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Nickolaenko, A. P. "ELF/VLF propagation measurements in the Atlantic during 1989." Journal of Atmospheric and Terrestrial Physics 57, no. 7 (1995): 821–33. http://dx.doi.org/10.1016/0021-9169(94)00055-s.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Liu, Wan-tong. "THE EFFECTS OF SOLAR FLARES ON VLF RADIOWAVE PROPAGATION." Chinese Journal of Space Science 13, no. 2 (1993): 134. http://dx.doi.org/10.11728/cjss1993.02.134.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Дружин, Г. И., В. М. Пухов, Д. В. Санников, Е. И. Малкин, and И. Е. Стасий. "VLF – RECORDER FOR THE STUDY OF NATURAL RADIO EMISSION." Вестник КРАУНЦ. Физико-математические науки, no. 2 (July 20, 2019): 105–16. http://dx.doi.org/10.26117/2079-6641-2019-27-2-105-116.

Full text

Abstract:

С целью исследования естественных щумовых электромагнитных излучений в Институте космофизических исследований и распространения радиоволн ДВО РАН разработан и создан ОНЧрегистратор, установленный на Камчатке, в экспедиционном пункте Карымшина. Непрерывные наблюдения, проведенные с помощью ОНЧ регистратора, позволили исследовать различные геофизические эффекты, связанные с распространением радиоволн, грозовой активностью, землетрясениями, циклонами. In order to study the natural noise electromagnetic radiation at the Institute of Cosmophysical Research and Radio Wave Propagation FEB RAS, a VLFr

APA, Harvard, Vancouver, ISO, and other styles

41

Manninen, J., N. G. Kleimenova, Yu V. Fedorenko, P. A. Bespalov, and T. Turunen. "New results of structured VLF emissions observed simultaneously at two closely located stations near <i>L</i> ~ 5.5." Annales Geophysicae 32, no. 9 (2014): 1163–67. http://dx.doi.org/10.5194/angeo-32-1163-2014.

Full text

Abstract:

Abstract. Simultaneous records of VLF (very low frequencies) emissions have been carried out at two ground-based stations located at similar geomagnetic latitudes near L ~ 5.5 and spaced in the longitude by ~ 400 km, Kannuslehto (KAN) in Finland and Lovozero (LOZ) in Russia, using quite similar VLF receivers with two calibrated orthogonal air-core loop antennas. We found that the general spectral properties of the VLF chorus emissions at these two stations were similar and typically have right-hand polarization. Contrary to VLF chorus, the short-period VLF emissions (periodic emissions, PE) in

APA, Harvard, Vancouver, ISO, and other styles

42

Reznikov, A. E., A. I. Sukhorukov, D. E. Edemskii, et al. "Investigations of the lower ionosphere over Antarctica via ELF-VLF radiowaves." Antarctic Science 5, no. 1 (1993): 107–13. http://dx.doi.org/10.1017/s0954102093000148.

Full text

Abstract:

The paper discusses ELF-VLF investigations of the low Antarctic ionosphere. Two new methods of lower ionospheric diagnostics are based on an investigation of the VLF electromagnetic field structure in the Earth-ionosphere cavity. One method deals with the analysis of local transverse cavity resonances in the near field of an emitter (a horizontal antenna) with a frequency (~1.5-8 kHz) in the range of the first few resonances. The other method, based on tweek investigations, is applicable under night conditions and enables the characteristics of the low ionosphere to be determined over a signal

APA, Harvard, Vancouver, ISO, and other styles

43

Vallée, Marc A., Michel Chouteau, and G. J. Palacky. "Effect of temporal and spatial variations of the primary signal on VLF total‐field surveys." GEOPHYSICS 57, no. 1 (1992): 97–105. http://dx.doi.org/10.1190/1.1443192.

Full text

Abstract:

Most of the airborne and ground VLF instruments presently used measure the total‐field response in addition to field ratios. Results of surveys using these instruments are adversely affected by spatial and temporal variations in the VLF primary field. Until now, the nature of such variations has not been studied from the point of view of geophysical surveying practice. Spatial variations are analyzed using radio propagation models. The most important result is the identification of primary field minima where surveys would be unreliable. Their dependence on the transmitter location is rather co

APA, Harvard, Vancouver, ISO, and other styles

44

Palit, S., T. Basak, S. K. Mondal, S. Pal, and S. K. Chakrabarti. "Modeling of the Very Low Frequency (VLF) radio wave signal profile due to solar flares using the GEANT4 Monte Carlo simulation coupled with ionospheric chemistry." Atmospheric Chemistry and Physics Discussions 13, no. 3 (2013): 6007–33. http://dx.doi.org/10.5194/acpd-13-6007-2013.

Full text

Abstract:

Abstract. X-ray photons emitted during solar flares cause ionization in the lower ionosphere (~ 60 to 100 km) in excess of what is expected from a quiet sun. Very Low Frequency (VLF) radio wave signals reflected from the D region are affected by this excess ionization. In this paper, we reproduce the deviation in VLF signal strength during solar flares by numerical modeling. We use GEANT4 Monte Carlo simulation code to compute the rate of ionization due to a M-class and a X-class flare. The output of the simulation is then used in a simplified ionospheric chemistry model to calculate the time

APA, Harvard, Vancouver, ISO, and other styles

45

Palit, S., T. Basak, S. K. Mondal, S. Pal, and S. K. Chakrabarti. "Modeling of very low frequency (VLF) radio wave signal profile due to solar flares using the GEANT4 Monte Carlo simulation coupled with ionospheric chemistry." Atmospheric Chemistry and Physics 13, no. 18 (2013): 9159–68. http://dx.doi.org/10.5194/acp-13-9159-2013.

Full text

Abstract:

Abstract. X-ray photons emitted during solar flares cause ionization in the lower ionosphere (~60 to 100 km) in excess of what is expected to occur due to a quiet sun. Very low frequency (VLF) radio wave signals reflected from the D-region of the ionosphere are affected by this excess ionization. In this paper, we reproduce the deviation in VLF signal strength during solar flares by numerical modeling. We use GEANT4 Monte Carlo simulation code to compute the rate of ionization due to a M-class flare and a X-class flare. The output of the simulation is then used in a simplified ionospheric chem

APA, Harvard, Vancouver, ISO, and other styles

46

Agapitov, O., V. Krasnoselskikh, Yu Zaliznyak, V. Angelopoulos, O. Le Contel, and G. Rolland. "Observations and modeling of forward and reflected chorus waves captured by THEMIS." Annales Geophysicae 29, no. 3 (2011): 541–50. http://dx.doi.org/10.5194/angeo-29-541-2011.

Full text

Abstract:

Abstract. Discrete ELF/VLF chorus emissions are the most intense electromagnetic plasma waves observed in the radiation belts of the Earth's magnetosphere. Chorus emissions, whistler-mode wave packets propagating roughly along magnetic field lines from a well-localized source in the vicinity of the magnetic equator to polar regions, can be reflected at low altitudes. After reflection, wave packets can return to the equatorial plane region. Understanding of whistler wave propagation and reflection is critical to a correct description of wave-particle interaction in the radiation belts. We focus

APA, Harvard, Vancouver, ISO, and other styles

47

Shi, Hanqing, Wei Xu, Binbin Ni, et al. "Predicting the Spatial Distribution of VLF Transmitter Signals Using Transfer Learning Models." Remote Sensing 17, no. 5 (2025): 871. https://doi.org/10.3390/rs17050871.

Full text

Abstract:

The D-region ionosphere (60–100 km altitude) is critical for radio communication and space weather research but cannot be easily measured because it is too low for satellites and too high for balloons. The most effective technique is to remotely sense by measuring Very-Low-Frequency (VLF, 3–30 kHz) waves emitted from man-made transmitters, a technique that was traditionally utilized to estimate the average ionospheric condition between the transmitter and receiver. Recently, various methods have been proposed to remotely sense the D-region ionosphere in large areas using network observation of

APA, Harvard, Vancouver, ISO, and other styles

48

Kumar, Sushil. "Waveguide Parameters of 19.8 kHz Signal Propagating over a Long Path." Research Letters in Physics 2009 (July 30, 2009): 1–4. http://dx.doi.org/10.1155/2009/216373.

Full text

Abstract:

The amplitude and phase of 19.8 kHz signal from navigational transmitter located in North West Cape, Australia, recorded at Suva, Fiji, have been utilized to determine the waveguide mode parameters. The propagation path is mixed over land and sea having Transmitter-Receiver Great Circle Path distance 6.7 Mm. The experimental values of the parameters were found to be consistent with the theoretical values calculated using the mode theory of VLF wave propagation in the waveguide.

APA, Harvard, Vancouver, ISO, and other styles

49

Schmitter, E. D. "Remote sensing and modeling of energetic electron precipitation into the lower ionosphere using VLF/LF radio waves and field aligned current data." Advances in Radio Science 13 (November 3, 2015): 233–42. http://dx.doi.org/10.5194/ars-13-233-2015.

Full text

Abstract:

Abstract. A model for the development of electron density height profiles based on space time distributed ionization sources and reaction rates in the lower ionosphere is described. Special attention is payed to the definition of an auroral oval distribution function for energetic electron energy input into the lower ionosphere based on a Maxwellian energy spectrum. The distribution function is controlled by an activity parameter which is defined proportional to radio signal amplitude disturbances of a VLF/LF transmitter. Adjusting the proportionality constant allows to model precipitation cau

APA, Harvard, Vancouver, ISO, and other styles

50

Kasahara, Y., F. Muto, T. Horie, et al. "On the statistical correlation between the ionospheric perturbations as detected by subionospheric VLF/LF propagation anomalies and earthquakes." Natural Hazards and Earth System Sciences 8, no. 4 (2008): 653–56. http://dx.doi.org/10.5194/nhess-8-653-2008.

Full text

Abstract:

Abstract. Relatively long-period (4 years) data on different propagation paths by means of Japanese-Pacific VLF/LF network observation, are used to obtain further statistical significance on the correlation of ionospheric perturbations as revealed by VLF/LF propagation anomalies with earthquakes. Earthquakes with magnitude greater than 6.0, taken place only within the fifth Fresnel zone of each great-circle path are selected for the correlation study. It is finally found based on the superimposed epoch analysis that the nighttime trend (average amplitude) exhibits a significant decrease exceed

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!