On the study of artificial ionospheric turbulence by means of stimulated electromagnetic emission

1994 ◽  
Vol 37 (7) ◽  
pp. 593-603 ◽  
Author(s):  
V. L. Frolov ◽  
G. N. Boiko ◽  
S. A. Metelev ◽  
E. N. Sergeev
Keyword(s):  
Electromagnetic Emission ◽  
Ionospheric Turbulence ◽  
Artificial Ionospheric Turbulence ◽  
Stimulated Electromagnetic Emission

Continuous measurement of stimulated electromagnetic emission spectra from HF excited ionospheric turbulence

Radio Science ◽  
1990 ◽  
Vol 25 (6) ◽  
pp. 1283-1289 ◽  
Author(s):  
W. T. Armstrong ◽  
R. Massey ◽  
P. Argo ◽  
R. Carlos ◽  
D. Riggin ◽  
...  
Keyword(s):  
Continuous Measurement ◽  
Emission Spectra ◽  
Electromagnetic Emission ◽  
Ionospheric Turbulence ◽  
Stimulated Electromagnetic Emission

Dependence of stimulated electromagnetic emission on the ionosphere and pump wave

1990 ◽  
Vol 95 (A10) ◽  
pp. 17233 ◽  
Author(s):  
T. B. Leyser ◽  
B. Thidé ◽  
H. Derblom ◽  
Å. Hedberg ◽  
B. Lundborg ◽  
...  
Keyword(s):  
Pump Wave ◽  
Electromagnetic Emission ◽  
Stimulated Electromagnetic Emission

The Multifractal Structure of Small-Scale Artificial Ionospheric Turbulence

2013 ◽  
Vol 22 (1) ◽  
Author(s):  
F. I. Vybornov ◽  
A. V. Rakhlin
Keyword(s):  
Experimental Studies ◽  
Multifractal Spectrum ◽  
Small Scale ◽  
Radio Waves ◽  
Ionospheric Turbulence ◽  
Heating Facility ◽  
Artificial Ionospheric Turbulence ◽  
Radio Sounding ◽  
Scale Turbulence ◽  
Disturbed Ionosphere

AbstractWe present the results of investigation of a multifractal structure of the artificial ionospheric turbulence when the midlatitude ionosphere is affected by high-power radio waves. The experimental studies were performed on the basis of the SURA heating facility with the help of radio sounding of the disturbed region of ionospheric plasma by signals from the Earth’s orbital satellities. In the case of vertical radio sounding of the disturbed ionosphere region, the measured multipower and generalized multifractal spectra of turbulence coincide well with similar multifractal characteristics of the ionosperic turbulence under the natural conditions. In the case of oblique sounding of the disturbance region at small angles between the line of sight to the satellite and the direction of the Earth’s magnetic field, a nonuniform structure of the small-scale turbulence with a relatively narrow multipower spectrum and small variations in the generalized multifractal spectrum of the electron density was detected.

scholarly journals An interferometer experiment to explore the aspect angle dependence of stimulated electromagnetic emission spectra

2005 ◽  
Vol 23 (1) ◽  
pp. 55-74 ◽  
Author(s):  
◽  
Yu. Yurik ◽  
La Hoz ◽  
◽  
◽  
...  
Keyword(s):  
Geomagnetic Field ◽  
Electromagnetic Emission ◽  
Density Fluctuations ◽  
Spectral Features ◽  
Langmuir Turbulence ◽  
Angular Structure ◽  
Frequency Spectra ◽  
Aspect Angle ◽  
Angle Dependence ◽  
Stimulated Electromagnetic Emission

Abstract. When the Earth's ionosphere is irradiated by a radiofrequency (RF) electromagnetic wave of sufficiently high power density and tuned to match a natural E- or F-region plasma frequency, ionospheric magnetoionic wave modes may be excited and may generate RF electromagnetic sideband waves via nonlinear interactions. These secondary emissions, which may then escape from the ionosphere, have been termed stimulated electromagnetic emission or SEE. The frequency spectra of this radiation has been studied extensively, and a number of characteristic spectral features have been identified and in some cases related to particular plasma processes. The separation in frequency between the RF pump and the harmonics of the local electron gyrofrequency is critical in determining the amount of anomalous absorption suffered by the pump wave and the spectral properties of the stimulated sidebands. The pump can excite electrostatic waves which do not propagate away but can in some cases be observed via radio-wave scattering from the electron density fluctuations associated with them. These enhanced density fluctuations are created by processes commonly referred to as upper-hybrid and Langmuir turbulence. Langmuir turbulence has been the subject of 930-MHz scattering observations with antenna scanning through several pre-selected angles between the geographic and geomagnetic zenith directions, and a preference for pointing angles between the Spitze angle and geomagnetic field-aligned was identified. Other phenomena, such as the generation of enhanced electron temperatures and artificial aurora, have more recently been shown to have special behavior at similar angles, near but apparently not quite at field-aligned. In view of this evidence for angular structure in several pump-induced effects, in light of the rich variety of SEE phenomena strongly dependent on the geomagnetic field via the frequency interval between the pump and the gyrofrequency harmonics, and in view of the not yet understood but complex relationship between electrostatic fluctuations and SEE, it is of interest to investigate experimentally whether a similar angular structure is present in the various spectral features of the SEE signals and to compare the results with radar and other observations of RF-pump-induced effects. To this end we describe a simple two-element radio interferometer designed to search for aspect angle dependence of SEE features. We present an example of the initial data produced by this system, and draw preliminary conclusions based on the example data.

Dynamic characteristics of signals scattered by artificial ionospheric turbulence

1991 ◽  
Vol 34 (1) ◽  
pp. 13-17
Author(s):  
V. A. Gudin ◽  
V. N. Deineko ◽  
V. N. Ivanov ◽  
Yu. A. Ignat'ev ◽  
P. B. Shavin
Keyword(s):  
Dynamic Characteristics ◽  
Ionospheric Turbulence ◽  
Artificial Ionospheric Turbulence
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