scholarly journals Spatiotemporal Characteristics of HF-Induced Ionospheric Turbulence Revealed by Diagnostic Stimulated Electromagnetic Emission and Test Radio Waves at HAARP

Radio Science ◽  
2018 ◽  
Vol 53 (12) ◽  
pp. 1506-1520 ◽  
Author(s):  
E. N. Sergeev ◽  
S. M. Grach ◽  
A. V. Shindin ◽  
E. V. Mishin ◽  
P. A. Bernhardt ◽  
...  
Keyword(s):  
Electromagnetic Emission ◽  
Radio Waves ◽  
Ionospheric Turbulence ◽  
Spatiotemporal Characteristics ◽  
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

scholarly journals HF-Induced Modifications of the Electron Density Profile in the Earth’s Ionosphere Using the Pump Frequencies near the Fourth Electron Gyroharmonic

2021 ◽  
Vol 13 (23) ◽  
pp. 4895
Author(s):  
Alexey V. Shindin ◽  
Evgeny N. Sergeev ◽  
Savely M. Grach ◽  
Gennady M. Milikh ◽  
Paul Bernhardt ◽  
...  
Keyword(s):  
Density Profile ◽  
Ionospheric Plasma ◽  
Pump Wave ◽  
Electromagnetic Emission ◽  
Electron Density Profile ◽  
Radio Waves ◽  
F Region ◽  
Plasma Density Profile ◽  
Hybrid Region ◽  
Hf Heating

We discuss results on plasma density profile modifications in the F-region ionosphere that are caused by HF heating with the frequency f0 in the range [(−150 kHz)–(+75 kHz)] around the fourth electron gyroharmonic 4fc. The experiments were conducted at the HAARP facility in June 2014. A multi-frequency Doppler sounder (MDS), which measures the phase and amplitude of reflected sounding radio waves, complemented by the observations of the stimulated electromagnetic emission (SEE) were used for the diagnostics of the plasma perturbations. We detected noticeable plasma expulsion from the reflection region of the pumping wave and from the upper hybrid region, where the expulsion from the latter was strongly suppressed for f0 ≈ 4fc. The plasma expulsion from the upper hybrid region was accompanied by the sounding wave’s anomalous absorption (AA) slower development for f0 ≈ 4fc. Furthermore, slower development and weaker expulsion were detected for the height region between the pump wave reflection and upper hybrid altitudes. The combined MDS and SEE allowed for establishing an interconnection between different manifestations of the HF-induced ionospheric turbulence and determining the altitude of the most effective pump wave energy input to ionospheric plasma by using the dependence on the offset between f0 and 4fc.

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.

scholarly journals A new upshifted spectral stimulated electromagnetic emission structure, observed between electron cyclotron harmonics

1997 ◽  
Vol 24 (13) ◽  
pp. 1647-1650 ◽  
Author(s):  
V. L. Frolov ◽  
E. N. Ermakova ◽  
L. M. Erukhimov ◽  
G. P. Komrakov ◽  
E. N. Sergeev ◽  
...  
Keyword(s):  
Electromagnetic Emission ◽  
Electron Cyclotron ◽  
Cyclotron Harmonics ◽  
Stimulated Electromagnetic Emission
Sign in / Sign up

Export Citation Format

Share Document