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Article
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ELF/VLF radio waves (300 Hz to 30 kHz) have been successfully generated via modulated HF (3-10 MHz) heating of the lower ionosphere in the presence of natural currents, most recently with the HAARP facility in Alaska. Generation is possible via amplitude modulation or via two techniques involving motion of the HF beam during the ELF/VLF cycle, know...

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... The ON-OFF modulation of the HF wave at ELF/VLF rates, allows HF energy to be converted into ELF/VLF radiation (see Sheerin and Cohen 2015 and references therein). Various configurations of the HF heating have been experimented to determine the best wave generation (Cohen 2009, 2012. To study the induced ionospheric effects many ground-based experiments are associated to HAARP, and in particular, ELF/VLF data are registered with broadband high-sensitivity receivers which consist of two orthogonal air-core loop antennae, measuring the two horizontal components of the magnetic field between 300 Hz and 40 kHz. ...
... W, 704 km SE of HAARP) are used. Their data are available from a web server named WALDO which is presented in Cohen (2020). ...
Article
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A spectrogram of Power Line Harmonic Radiation (PLHR) consists of a set of lines with frequency spacing corresponding exactly to 50 or 60 Hz. It is distinct from a spectrogram of Magnetospheric Line Radiation (MLR) where the lines are not equidistant and drift in frequency. PLHR and MLR propagate in the ionosphere and the magnetosphere and are recorded by ground experiments and satellites. If the source of PLHR is evident, the origin of the MLR is still under debate and the purpose of this paper is to understand how MLR lines are formed. The ELF waves triggered by High-frequency Active Auroral Research Program (HAARP) in the ionosphere are used to simulate lines (pulses of different lengths and different frequencies). Several receivers are utilized to survey the propagation of these pulses. The resulting waves are simultaneously recorded by ground-based experiments close to HAARP in Alaska, and by the low-altitude satellite DEMETER either above HAARP or its magnetically conjugate point. Six cases are presented which show that 2-hop echoes (pulses going back and forth in the magnetosphere) are very often observed. The pulses emitted by HAARP return in the Northern hemisphere with a time delay. A detailed spectral analysis shows that sidebands can be triggered and create elements with superposed frequency lines which drift in frequency during the propagation. These elements acting like quasi-periodic emissions are subjected to equatorial amplification and can trigger hooks and falling tones. At the end all these known physical processes lead to the formation of the observed MLR by HAARP pulses. It is shown that there is a tendency for the MLR frequencies of occurrence to be around 2 kHz although the exciting waves have been emitted at lower and higher frequencies. Graphical Abstract
... Interestingly, however, even if perfect knowledge of global lightning activity did in fact exist and were available to a hacker, it would still be extremely difficult, if not impossible, to synthesize LF data. As the shape of a sferic evolves with distance and as a function of time of day, season, and other factors, synthesizing accurate LF data would require computationally intense physical models of propagation between the Earth and ionosphere that cannot be run anywhere near real time [47]. As such, the quasi-random distribution of global lightning makes for a one-way function that allows easy authentication but is practically impossible to synthesize. ...
... Technically, the magnetic field emission from a current density in the three-dimensional space can be calculated from the magnetic retarded vector potential. To explain in the mathematical format, the magnetic retarded vector potential, − → A , for a given point source in the space can be calculated as [47]: ...
... However, even if the attacker can compromise all of the three stages, he still needs to synthesize the LF data to implement malicious activities in the substation. As the shape of a sferic evolves with distance and as a function of time of day, season, and other factors, synthesizing accurate LF data would require computationally intense physical models of propagation between the Earth and ionosphere that cannot be run in real time [47]. Indeed, the quasi-random distribution of global lightning makes a one-way function that allows easy authentication but is practically impossible to synthesize. ...
... During some last decades ionosphere and magnetosphere are of a wide use in the world to solve a great number of fundamental and applied problems including those from location, remote sensing and communication [1][2][3][4][5][6][7][8]. ...
Article
This paper is dealt with control from satellite of artificial disturbances in the ionosphere. Such disturbances can be excited by means of interaction of powerful radiation generated by earth-based heaters with the ionosphere. If next cut-in of a heater, periodicity of cut-ins, parameters of signals radiated by a heater (carrier frequency, modulation frequency, modulation format) are unknown and one has to design an orbit group capable to register primary radiation of a heater or products of its activity then such a problem is suggested to be referred to as inverse problem. A great number of orbit groups differing in parameters come out of solution of inverse problem. To choose the best solution (design of orbit group with optimal parameters) a model function allowing to give an integral description for orbit group and connecting external parameters of orbit group (information being acquired by orbit group from the heater, financial expenditure and period of time being required to deploy the orbit group) is synthesized. External parameters describe orbit group from customer's point of view. External parameters of orbit group are functions of its internal parameters (type and parameters of orbits, quantity of orbits, relative orientation of orbits, number of satellites pro a single orbit and their total number in the orbit group, arrangement of satellites for each orbit). Internal parameters describe orbit group from designer's point of view. Three criterions and appropriate methods for solution of inverse problem consisting in monitoring of earth-based heater are considered in this paper. This criterions and methods take into account the most widespread customer's limitations for external parameters of orbit group. A solution of inverse problem using criterion of heater's minimum non-observation is set forth as an example. This example shows that monitoring of primary radiation generated by a standard heater on conditions that a) one has no limitations in funding and time to deploy an orbit group, b) one can obtain no a priori data about heater's activity and c) one must provide non-stop monitoring of primary radiation generated by a heater, we obtain an orbit group consisting of eight satellites on high-elliptic orbit (“Molniya”-type) with longitude correction in 34°. © 2018 Radioelektronika, Nanosistemy, Informacionnye Tehnologii. All rights reserved.
... ii Acknowledgements I want to commence this section with a quote, "If you have learned much (scholarly wisdom), do not take credit for yourself; it is for this reason that you have been formed" [16]. x ...
... Artificially generated signals include minimum-shift-keyed (MSK) modulated US Navy transmitters, which operate above 20 kHz and act as communication links with submarines. Also seen on the high end of the spectrum are the Omega (though now decommissioned) and pulsed Russian alpha beacon signals, which follow a regular frequency pattern from three different sources which act as narrowband noise sources (figure 3-8) [3] [4].On the low end of the spectrum, the ever present 50/60 Hz power-line hum and harmonics are visible up to 5 kHz or higher (figure 3-9) [16]. Naturally generated signals include sum total of all sferics arriving from all directions originating from all lightning sources around the world which act as a broadband noise source ( figure 3-8). ...
... Another naturally generated signals, common at more extreme magnetic latitudes, are whistlers ( figure 3-8), which result from lightning-generated radiation that has propagated through the magnetosphere along field-aligned ducts of enhanced conductivity and re-entered the earth-ionosphere waveguide. Another natural noise source originating from the magnetosphere is chorus ( figure 3-9), which are emissions consisting of quasimonochromatic signals from hundreds of hertz to 5 kHz [3] [4] [16]. ...
Thesis
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In this work, a receiver for detecting magnetic fields generated by Cloud to Ground lightning discharges in the frequency range from 3KHz to 30 KHz is designed and a part of an analog section, comprising of the input transformer, Low Noise Amplifier (LNA) and some signal conditioning circuits including Variable Gain Amplifier (VGA), High Pass Filter (HPF) for power line harmonics removal, output amplifier, output matching transformer, and a calibration circuit for testing, is developed.
... The beam pattern radiated by the HAARP array in different modes.Figure andtable adapted from Cohen[7] ...
... Continental-scale detections of HAARP-generated ELF signals. Adapted from Cohen[7] top left panel, shows the placement of some AWESOME receivers for detection of subionospherically propagating VLF signals generated above the HAARP facility using AM modulated HF heating, at three different sites inAlaska: Chistochina (62.61 N, 144.62W, 37 km from HAARP), Juneau (58.59 N, 134.90 W, 704 km SE of HAARP), and Kodiak (57.87 N, 152.88 W, 661 km SW of HAARP). Each of the Alaska sites use large 1 Ω antennas 18 m 2 in area or larger. ...
Conference Paper
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The ionosphere is the ionized uppermost layer of our atmosphere (from 70 – 500 km altitude) where free electron densities yield peak critical frequencies in the HF (3 – 30 MHz) range. The ionosphere thus provides a quiescent plasma target, stable on timescales of minutes, for a whole host of active plasma experiments. High power RF experiments on ionospheric plasma conducted in the U.S. have been reported since 1970. The largest HF transmitter built to date is the HAARP phased-array HF transmitter near Gakona, Alaska which can deliver up to 3.6 Gigawatts (ERP) of CW RF power in the range of 2.8 – 10 MHz to the ionosphere with microsecond pointing, power modulation, and frequency agility. With an ionospheric background thermal energy in the range of only 0.1 eV, this amount of power gives access to the highest regimes of the nonlinearity (RF intensity to thermal pressure) ratio. HAARP’s unique features have enabled the conduct of a number of unique nonlinear plasma experiments in the interaction region of overdense ionospheric plasma including generation of artificial aurorae, artificial ionization layers, VLF wave-particle interactions in the magnetosphere, parametric instabilities, stimulated electromagnetic emissions (SEE), strong Langmuir turbulence (SLT) and suprathermal electron acceleration. Diagnostics include the Modular UHF Ionospheric Radar (MUIR) sited at HAARP, the SuperDARN-Kodiak HF radar, spacecraft radio beacons, HF receivers to record stimulated electromagnetic emissions (SEE) and telescopes and cameras for optical emissions. We report on short timescale ponderomotive overshoot effects, artificial field-aligned irregularities (AFAI), the aspect angle dependence of the intensity of the HF-enhanced plasma line, and production of suprathermal electrons. One of the primary missions of HAARP, has been the generation of ELF (300 – 3000 Hz) and VLF (3 – 30 kHz) radio waves which are guided to global distances in the Earth-ionosphere waveguide. We review recent efforts to improve the efficiency of the generation ELF/VLF and develop alternative mechanisms that do not require a natural ionospheric current. Applications include the controlled study of ionospheric irregularities affecting spacecraft communication and navigation systems.
... It is reasonable to expect that the extent of a local vertical resonance in the Earth-ionosphere waveguide will be limited to the order of the size of the source and the wavelength in question. The ionospheric heated region above HAARP for a 2.75 MHz carrier has a diameter of approximately 50 km when first-order side lobes are taken into account [Cohen, 2009]. The free space wavelengths for 2 kHz, 4 kHz, and 6 kHz are 150 km, 75 km, and 50 km, respectively. ...
... Four ionospheric D region profiles and electron-neutral collision frequency used to createFigure 8. Profile 1: winter night, Profile 2: summer night, Profile 3: winter day, and Profile 4: summer day[Cohen, 2009]. ...
Article
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Modulated ionospheric heating experiments are performed with the High Frequency Active Auroral Research Program (HAARP) facility in Gakona, Alaska for the purpose of generating extremely low frequency (ELF) and very low frequency (VLF) waves. Observations are made at three different azimuths from the heating facility and at distances from 37 km to 99 km. The polarization of the observed waves is analyzed in addition to amplitude as a function of modulation frequency and azimuth. Amplitude and eccentricity are observed to vary with both azimuth and distance from the heating facility. It is found that waves radiated at azimuths northwest of the facility are generated by a combination of modulated Hall and Pedersen currents, while waves observed at other azimuths are dominated by modulated Hall currents. We find no evidence for vertical currents contributing to ground observations of ELF/VLF waves. Observed amplitude peaks near multiples of 2 kHz are shown to result from vertical resonances in the Earth-ionosphere waveguide and variations of the frequency of these resonances can be used to determine the D-region ionosphere electron density profile in the vicinity of the HF heater.
... It is reasonable to expect that the extent of a local vertical resonance in the Earth-ionosphere waveguide will be limited to the order of the size of the source and the wavelength in question. The ionospheric heated region above HAARP for a 2.75 MHz carrier has a diameter of approximately 50 km when first-order side lobes are taken into account [Cohen, 2009]. The free space wavelengths for 2 kHz, 4 kHz, and 6 kHz are 150 km, 75 km, and 50 km, respectively. ...
... Four ionospheric D region profiles and electron-neutral collision frequency used to createFigure 8. Profile 1: winter night, Profile 2: summer night, Profile 3: winter day, and Profile 4: summer day[Cohen, 2009]. ...
... It was experimentally observed that ELF radiation escapes from the Earth-ionosphere waveguide and reaches the Van Allen belts [14][15][16][17]. In the ionospheric spherical cavity, the ELF radiation power density, , is related to the energy density inside the cavity,W , by means of the wellknown expression: ...
... It is important to note that Eq.(16) refers to the case of ordinary matter (non-coherent matter). In the case of superconductors the radiation is absorbed by the Cooper-pairs fluid (coherent part of the superconductors) and there is no scattering of the incident radiation. ...
Article
Two gravitational effects related to rotating masses are described. The first is the decreasing of the gravitational mass when the rotational kinetic energy is increased. In the case of ferromagnetic materials, the effect is strongly increased and the gravitational mass can even become negative. The second is the gravitational shielding effect produced by the decreasing of the gravitational mass of the rotating mass.
... Signals were also detected at distances of 550 km from Tromsø [Barr et al., 1986], and 2200 km [Barr et al., 1991]. [6] More recently, the HAARP near-field phased-array HF facility near Gakona, Alaska (62 22′ N, 145 9′ W), has been used to generate ELF/VLF signals that have been observed as far as 4400 km [Moore et al., 2007; Cohen et al., 2010c], as well as injected into the magnetosphere and observed in the geomagnetic conjugate region [Inan et al., 2004; Gołkowski et al., 2008, 2011]. In 2007, an upgrade of HAARP was completed, increasing its capacity from 48 active elements, 960 kW input power, and 175 MW ERP (at 3.25 MHz), to 180 active elements, 3.6 MW input power, and $400 MW ERP (at 3.25 MHz). ...
... However, the choice of HF heating parameters is also quite important. For instance, proper utilization of motion of the HF beam can yield 7–11 dB more ELF/VLF power in the Earth-ionosphere waveguide [Cohen et al., 2008b, 2010b], and 5–7 dB more power radiated into the magnetosphere [Cohen et al., 2011]. [8] We consider the effect of HF frequency, beam width, and ERP, on generated ELF/VLF amplitudes, both near the heated region, at longer distances in the Earth-ionosphere waveguide, and in the magnetosphere. ...
... could be due to the fact that at higher HF frequencies, the absorption and consequent ELF/VLF generation occurs at slightly higher altitudes. In addition, the 1 kHz peak also becomes more pronounced as the beam is broadened, since the broadening decreases the ERP and therefore lowers the altitude of generation [ Cohen, 2010, p.49]. With less ionosphere between the source and the top of the magnetosphere , the decrease in radiation efficiency becomes slightly less important. ...
Article
Full-text available
1] ELF/VLF (0.3–30 kHz) wave generation is achievable via modulated HF (3–30 MHz) heating of the lower ionosphere in the presence of natural currents such as the auroral electrojet. Using the 3.6 MW High Frequency Active Auroral Research Program (HAARP) facility near Gakona, AK, we investigate the effect of HF frequency and beam size on the generated ELF/VLF amplitudes, as a function of modulation frequency, and find that generation in the Earth-ionosphere waveguide generally decreases with increasing HF frequency between 2.75–9.50 MHz. HAARP is also capable of spreading the HF power over a wider area, and we find that a larger beam area yields larger generated amplitudes on the ground. Measurements are shown to generally agree with a theoretical model, which is then applied to also predict the effect of HF beam parameters on magnetospheric injection with HAARP. (2012), HF beam parameters in ELF/ VLF wave generation via modulated heating of the ionosphere, J. Geophys. Res., 117, A05327, doi:10.1029/2012JA017585.
Conference Paper
The energetic protons trapped in the inner Van Allen belt pose a risk to humans and spacecraft operating in Low Earth Orbit (LEO). These particles come from cosmic rays, solar storms and other processes, and they are a hindrance to development of space technologies. The Radiation Belt Remediation (RBR) idea has been proposed as a way to solve this problem through Ultra/Very Low Frequency (VLF/ULF) transmissions in the magnetosphere capable of inducing pitch angle scattering of the hazardous particles and precipitating them into the atmosphere. Whistler-type emissions (VLF band, tens of kHz) have been extensively studied for precipitation of energetic trapped electrons, but much less work has been devoted to the controlled removal of inner belt protons. The latter would require the man-made radiation of Electromagnetic Ion Cyclotron (EMIC) waves into the magnetosphere (ULF band, less than 10 Hz), the frequency of which is close to the cyclotron frequency of the trapped protons. In this paper we first identify the space-borne transmitter capable of radiating EMIC waves, and we estimate its radiation impedance and radiation pattern. The selected antenna configuration consists of a DC rotating coil, which is equivalent to two AC phased-orthogonal coils but with negligible self-inductance. However, the radiation resistance of magnetic dipoles is very small. For this reason, we propose a design based on superconductors and multiple turn arrangements. One of the most challenging aspects of using superconductors in space is their cooling system. This paper presents a preliminary thermal and mechanical design of a superconducting coil antenna capable of radiating EMIC waves into the magnetosphere. The coil is composed of high temperature superconducting tapes (HTS), which have to be kept below 77 K. Active thermal control and the use of cryogenics are therefore required to reject the heat coming from environmental sources. This preliminary design is used to calculate the po- er radiated from the antenna, its radiation pattern and its effect on the energetic proton population of the inner Van Allen belt. The feasibility of the remediation concept, as well as a scientific mission scaled down to detectability of the proton precipitating fluxes are finally addressed at the end of the paper.