Electromagnetic field measurements in ULF-ELF-VLF [0.001 Hz–100 KHz] bands

Abstract. We are reporting the technological and scientific objectives of the MEM project. The MEM project has been activated in the INGV Observatory of L'Aquila to create in Central Italy a network of observatories in order to monitoring the electromagnetic signals in the frequency band [0.001 Hz–100 kHz]. Some examples of the instrumentation developed in the frame of the project are reported. An innovative technique, based on the wide band interferometry is proposed to obtain detailed information concerning the several detected electromagnetic sources. Moreover, data from each station will be elaborated to investigate different sectors as the structure of ground electric conductibility, the electromagnetic phenomena connected with seismic activity, the separation of the electromagnetic fields originated in the Earth's interior and the electromagnetic phenomena originated in the magnetosphere, in the ionosphere and in the Earth-ionosphere cavity.

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Magnetic and Electromagnetic signals related to tectonic activity: updates and new analyses on measurements in Central Italy

Natural Hazards and Earth System Science ◽

10.5194/nhess-5-925-2005 ◽

2005 ◽

Vol 5 (6) ◽

pp. 925-930

Author(s):

D. Di Mauro ◽

S. Lepidi ◽

A. Meloni ◽

P. Palangio

Keyword(s):

Seismic Activity ◽

Spatial Scales ◽

Central Italy ◽

Wide Band ◽

Tectonic Activity ◽

Electromagnetic Properties ◽

National Network ◽

Tectonic Events ◽

Electromagnetic Signals

Abstract. Tectonomagnetic field observations from absolute magnetic field levels have been collected in Central Italy since 1989 by means of a network of four absolute magnetometer stations, including the geomagnetic observatory of L'Aquila (42°23 N, 13°19 E) used as reference for differentiation; also electromagnetic variations from VLF signals have been recorded in the last years by means of VLF search coil wide-band antennas. Many reports proved the occurrence of electromagnetic effects clearly related to tectonic events (seismic and volcanic activity) in active areas of our planet. In this paper we show the variation of some electromagnetic parameters which could be related to local and regional seismic activity for the most recent years 2002 and 2003. We also report the seismic activity recorded in this area by the Italian seismic national network. Some tentative analysis (in the wavelets and statistical approach) on the historical and recent dataset allow a better characterization of electromagnetic properties of the study area, at different temporal and spatial scales.

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Analysis on Lightning Electromagnetic Fields

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.401-403.350 ◽

2013 ◽

Vol 401-403 ◽

pp. 350-353 ◽

Cited By ~ 2

Author(s):

Pi Cui Zhang ◽

Wei He ◽

Liu Ling Wang ◽

Li Feng Ma

Keyword(s):

Electromagnetic Field ◽

Spatial Distribution ◽

Electromagnetic Fields ◽

Maxwell Equations ◽

Practical Significance ◽

Lightning Protection ◽

Perfect Conductor ◽

Fundamental Theory ◽

Lightning Current ◽

The Earth

t is generally needed to know precisely spatial distribution of lightning electromagnetic fields in the lightning protection measurements. Therefore, the research on the lightning electromagnetic field is of practical significance. In this paper, the Maxwell equations were used to calculate and analyze the spatial distribution of lightning electromagnetic fields surrounding lightning current. And the expressions of lightning current electromagnetic fields were deduced under the assumption that the earth was under the condition of perfect conductor. The spatial distributions of the components of lightning electromagnetic fields have been plotted by Matlab. The results would provide fundamental theory for the research of lightning electromagnetic field and lightning protection measurements.

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Instrumental assessment of mobile communication base station electromagnetic field exposure

Russian Journal of Occupational Health and Industrial Ecology ◽

10.31089/1026-9428-2020-60-11-853-856 ◽

2020 ◽

Vol 60 (11) ◽

pp. 853-856

Author(s):

Sergey Yu. Perov ◽

Olga V. Belaya

Keyword(s):

Electromagnetic Field ◽

Electromagnetic Fields ◽

Reference Signal ◽

Field Measurements ◽

Measurement Methods ◽

Base Stations ◽

Frequency Channel ◽

Theoretical Maximum ◽

Maximum Value ◽

Frequency Selective

Introduction. Monitoring and ensuring safe operating conditions of modern base stations for occupational and general public exposure is relevant with the use of methods for measuring electromagnetic fields, which allow to assess the contribution of different sources to the overall level of the electromagnetic background, taking into account the dynamic features of base stations and the spectral electromagnetic characteristics. The aim of study is the levels of electromagnetic fields assessment from modern base stations using broadband and selective measurement methods, as well as the possibility of predicting the worst exposure conditions. Materials and methods. The levels of electromagnetic fields from base stations according to the LTE2600 standard were evaluated at the maximum transmission traffic (laboratory mearements) and at real variable traffic (field measurements). For broadband measurements, the power density (PD) was estimated, for selective measurements, the PD level in the LTE frequency channel (frequency-selective measurements) and the PD level of the reference signal (code-selective measurements) were evaluated. The theoretical maximum PD level was calculated from the maximum value of the reference signal. Results. When simulating the maximum intensity of data traffic, the PD level in the LTE channel was 94.51-101.39% of the calculated maximum value. According to field measurements, the values of electromagnetic field levels obtained from frequency-selective measurements in the LTE frequency channel were less than the corresponding values estimated from the results of broadband measurements, and were no more than 25% of the theoretical maximum. Conclusions. The use of selective approach and measurement methods made it possible to estimate the maximum possible contribution of a single source to the overall level of the electromagnetic background and to predict the worst conditions for human exposure.

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Artificial and natural electromagnetic signals revealed during two years in the Amare cave (Central Italy)

Annals of Geophysics ◽

10.4401/ag-4161 ◽

1994 ◽

Vol 37 (5 Sup.) ◽

Author(s):

F. Bella ◽

R. Bella ◽

P. F. Biagi ◽

M. Caputo ◽

G. Della Monica ◽

...

Keyword(s):

Solid State ◽

Electromagnetic Fields ◽

Natural Frequencies ◽

Central Italy ◽

Southern Slope ◽

Qualitative Explanation ◽

Weather Events ◽

Electromagnetic Signals ◽

Set Up ◽

Electric Signals

n 1990, some instrumentation was set up in the Amare cave (southern slope of the Gran Sasso chain, L'Aquila) in order to pick up electric signals ranging from 0.3 to 300 kHz, magnetic signals from 0.3 to 30 kHz and seismoacoustic signals by means of three geophones with natural frequencies of 0.3 kHz, 25 kHz and 150 kHz. Data are recorded every ten minutes on a solid state memory. The analysis of the data allows us to establish the existence of electromagnetic fields of distant origin connected with broadcastings and with tropical lightning activity and the discontinuous presence of local electric and magnetic signals, coupled with seismoacoustic ones, connected with weather events. A qualitative explanation of these near fields is given.

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GRACE-FO and Swarm integrated data analysis reveals ionospheric disturbances on the accelerometer measurements

10.5194/egusphere-egu2020-12931 ◽

2020 ◽

Author(s):

Myrto Tzamali ◽

Athina Peidou ◽

Spiros Pagiatakis

Keyword(s):

Magnetic Field ◽

Electromagnetic Field ◽

Electric Field ◽

Poynting Vector ◽

Field Measurements ◽

Temporal Variations ◽

Space Environment ◽

The Earth ◽

Leo Satellites ◽

The Magnetic Field

<p>Low Earth Orbit (LEO) satellites are subject to numerous disturbances related to the Earth&#8217;s upper ionosphere. Perturbations induced by the activity of the electromagnetic field (EM) at the upper ionospheric layers have not been fully understood yet. This study focuses on the disturbances shown on GRACE-FO accelerometer measurements when the EM field was disturbed by an intense geomagnetic storm occurred on August 2018. A thorough analysis of the accelerometer measurements of GRACE-C as well as the magnetic and electric field measurements from Swarm constellation is conducted, to enlighten their impulse-response relationship. We derive the temporal variations of the magnetic field by removing the main static field and we calculate the Poynting vector employing the Swarm magnetic field measurements and electric field data, by implementing rigorous data analyses to analyze the spatiotemporal characteristics of the energy flow of the electromagnetic field. Results show that GRACE-C accelerometer measurements are highly disturbed in the higher latitudes especially near the auroral regions. The signature of the spatial temporal variations of the magnetic field and the Poynting vector demonstrates very similar behaviour with GRACE-C disturbances. Cross wavelet analysis between Poynting vector and GRACE-C accelerometer disturbances shows a very strong coherence. With the two LEO missions, i.e. GRACE-FO and Swarm, orbiting the Earth in very similar orbits, further analysis towards integrating their measurements will enhance our understanding of the interaction of LEO satellites with the space environment and how this interaction is depicted in their measurements.</p>

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The study of the electromagnetic anomalies linked with the Earth's crustal activity in the frequency band [0.001 Hz–100 kHz]

Natural Hazards and Earth System Science ◽

10.5194/nhess-7-507-2007 ◽

2007 ◽

Vol 7 (5) ◽

pp. 507-511 ◽

Cited By ~ 2

Author(s):

P. Palangio ◽

C. Di Lorenzo ◽

F. Masci ◽

M. Di Persio

Keyword(s):

Electric Fields ◽

Frequency Band ◽

Central Italy ◽

Tectonic Activity ◽

Normal Behaviour ◽

Know How ◽

Single Station ◽

Lower Frequency Band ◽

Electromagnetic Signals

Abstract. The technological and the scientific objectives of the MEM (Magnetic and Electric fields Monitoring) project concerning to the study of the electromagnetic signals linked with the Earth's crustal activity are reported. The MEM project has been activated in Central Italy to create a network of observatories so as to monitoring the electromagnetic signals, both natural and artificial, in the frequency band [0.001 Hz–100 kHz]. Some examples of the developed instrumentation and the know-how transfer to the industry are reported. We also report some results obtained in the first MEM station installed in the area of the INGV (Italian Istituto Nazionale di Geofisica e Vulcanologia) Observatory of L'Aquila. Using the single station magnetotelluric approach we have obtained some valuables information about the underground resistivity structure in the area of the measurement station. Concerning to the study of the magnetic signals linked with the tectonic activity we have reported an example of the long term behaviour of the magnetic induction vectors characteristics in the lower frequency band [0.001–0.5] Hz, showing their normal behaviour when no large crustal changes due to geodynamical processes are present.

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