Propagation of low-frequency electromagnetic waves in the earth-ionosphere waveguide

Bellyustin, N. S.; Polyakov, S. V.

doi:10.1007/bf01034276

Cited by 4 publications

(7 citation statements)

References 1 publication

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“…In this case, for the frequency f = 1 Hz inequality (23) is fulfilled, but with a small margin. In accordance with [12] …”

Section: Ionopspheric Alfvén Resonance At the Terminatorsupporting

confidence: 84%

“…In [12], general cumbersome formulas are given for the coefficients in Eq. (19) through the angle θ between the vertical line and the external magnetic field and the components g and η of the dielectric permittivity tensor ε in the coordinate system with the z axis along the external magnetic field:…”

Section: Ionopspheric Alfvén Resonance At the Terminatormentioning

confidence: 99%

“…This means that the main effect of nonideality of the problem is the wave packet spread across the terminator. Using the results given in [12], we write simplified approximate expressions for expansion coefficients (19) of interest to us:…”

Section: Ionopspheric Alfvén Resonance At the Terminatormentioning

confidence: 99%

“…The mathematical tools for description of the discussed distortions were proposed in [12], where the expansion k z = k 0 n + αk y + βk 2 x + γk 2 y + . .…”

Section: Ionopspheric Alfvén Resonance At the Terminatormentioning

confidence: 99%

“…The z axis is vertically directed. In [12], the inclination of the Earth's magnetic field was taken into account, and it was assumed that the magnetic field lies in the yz plane. The coefficients in Eq.…”

Section: Ionopspheric Alfvén Resonance At the Terminatormentioning

confidence: 99%

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Boundary Condition for a Nonstationary Horizontal Ionospheric Current at the Terminator with Allowance for Flowing of a Part of the Current into the Upper Ionosphere and Magnetosphere

Polyakov

2015

Radiophys Quantum El

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We consider the boundary condition for horizontal ionospheric currents at the terminator with allowance for the possibility of flowing of a part of the current into the upper ionosphere and magnetosphere. Theoretical models of extremely low frequency field propagation presented in the literature assume that the horizontal ionospheric current component orthogonal to the terminator is continuous at the terminator. A well-known boundary condition for Alfvén waves in a horizontally inhomogeneous ionosphere is used as the basis for theoretical constructs.

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“…In this case, for the frequency f = 1 Hz inequality (23) is fulfilled, but with a small margin. In accordance with [12] …”

Section: Ionopspheric Alfvén Resonance At the Terminatorsupporting

confidence: 84%

Section: Ionopspheric Alfvén Resonance At the Terminatormentioning

confidence: 99%

Section: Ionopspheric Alfvén Resonance At the Terminatormentioning

confidence: 99%

“…The mathematical tools for description of the discussed distortions were proposed in [12], where the expansion k z = k 0 n + αk y + βk 2 x + γk 2 y + . .…”

Section: Ionopspheric Alfvén Resonance At the Terminatormentioning

confidence: 99%

Section: Ionopspheric Alfvén Resonance At the Terminatormentioning

confidence: 99%

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Boundary Condition for a Nonstationary Horizontal Ionospheric Current at the Terminator with Allowance for Flowing of a Part of the Current into the Upper Ionosphere and Magnetosphere

Polyakov

2015

Radiophys Quantum El

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ELF and VLF radiation from the “polar electrojet antenna”

Barr¹,

Stubbe²

1984

Radio Science

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First, an approximate evaluation is made of the ELF/VLF dipole moment of the polar electrojet antenna established by ionospheric heating via the use of powerful HF waves amplitude modulated with frequencies in the ELF/VLF range. Then, the theory of reciprocity is used to determine the magnitude of the ELF/VLF waveguide excitation produced by such a dipole immersed in the ionosphere. Propagation under a series of ionospheres ranging from quiet auroral nightime to disturbed auroral daytime is considered. contrast between land and seawater, this method was found not to be feasible in practice [Wait, 1979; Bart, 1980]. More recently, Getmantsev et al. [1974] have shown that the D region of the ionosphere, when illuminated by a powerful source of HF radiation amplitude modulated at an extremely low frequency, can also act as a source of ELF radiation. The observed field strengths were quite small (• 10-1ttV m-•) and were explained in terms of nonlinear detection of the modulated HF signals in the ionosphere [Kotik and Trakhtengerts, 1975]. This work at midlatitudes has been continued by Ferraro et al. [1982] who, working with the powerful HF heating facility at Arecibo, have also generated ELF/VLF radiowaves in the D region of the ionosphere. Stubbe and Kopka [1977] suggested that by working at high latitudes, in the region of the polar electrojet, a much more effective VLF/ELF transmitting source could be produced in the ionosphere. Such a system has been in operation near Tromso in Norway for 3 years, and typical field strengths • 100 ttV m-x have been recorded 20 km south of the heating site when operating with an HF effective radiated power of 100 MW modulated at a few kilohertz [Stubbe et al., 1981[Stubbe et al., , 1982. ELF radiation from the electrojet, when heated byRussian low-frequency transmitters, has also been invoked as a mechanism to explain the reception of 1-kHz "pips" on ELF receivers in Northern Europe [Cannon, 1982]. Initial estimates of the radiation efficiency of the polar electrojet antenna (PEJ) have assumed the antenna to be in free space [Stubbe and Kopka, 1977; Cannon et al., 1982], but more recent calculations at ELF by Bart and Stubbe [1983] have shown that these simplistie analyses tend to overestimate the effective radiated power. This current work extends the ELF calculations of Barr and Stubbe into the VLF range and calculates the excitation of the five least 1111 FROM POLAR ELECTROJET 1113 BARR AND STUBBE: RADIATION FROM POLAR ELECTROJET Wait, J. R., On natural slot antennas, Radio Sci., 14(5), 765-766, ß 1979. R. Barr,

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On the efficiency of ionospheric ELF generation

Papadopoulos¹,

Chang²,

Vitello³

et al. 1990

Radio Science

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The scaling laws that control the efficiency of converting ground-based HF power to ELF power by using modulation of the polar electrojet current is discussed. The analysis is based on kinetic calculations of the modification of the ionospheric conductivity by HF waves in conjunction with the experimental results reported from the Tromso Max Planck and the Alaska high power auroral simulation (HIPAS) facilities. It is shown that the efficiency can be increased by more than a factor of 10 4 by (1) using phasing to sweep the antenna beam over an area spanned by a maximum tilt of 35 ø, on a time scale faster than the cooling rate at the heating altitude (<100/•s) and (2) localization of the heating at the E region (90-100 km) where electron runaway can be induced resulting in substantial modification of the Pederson conductivity.

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Propagation of low-frequency electromagnetic waves in the earth-ionosphere waveguide

Cited by 4 publications

References 1 publication

Boundary Condition for a Nonstationary Horizontal Ionospheric Current at the Terminator with Allowance for Flowing of a Part of the Current into the Upper Ionosphere and Magnetosphere

Boundary Condition for a Nonstationary Horizontal Ionospheric Current at the Terminator with Allowance for Flowing of a Part of the Current into the Upper Ionosphere and Magnetosphere

ELF and VLF radiation from the “polar electrojet antenna”

On the efficiency of ionospheric ELF generation

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