The lower ionosphere response to its disturbances by powerful radio waves

© 2017. The paper presents data from some campaigns at Sura heating facility in 2011-1016. The experiments on probing of the artificial disturbed region of the lower ionosphere were carried out at two observation sites. One of them was located near Vasil'sursk 1. km from Sura facility (56.1°N; 46.1°E) and the other site was located at the Observatory (55.85°N; 48.8°E) of Kazan State University, 170. km to the East. Investigation of the features of the disturbed region of the lower ionosphere based on its diagnostics by the methods of the vertical sounding and oblique backscattering is the main goal of this paper. Ionosphere disturbance was fulfilled by the effect of the powerful radio wave of the ordinary or extraordinary polarization emitted by transmitters of the Sura facility with effective radiated power ERP = 50-120. MW at the frequency of 4.3, 4.7 and 5.6. MHz. Pumping waves were emitted with period from 30. s to 15. min. The disturbed region of the ionosphere in Vasil'sursk was probed by the vertical sounding technique using the partial reflexion radar at the frequency of 2.95 and 4.7. MHz. For the oblique sounding of the disturbed region the modified ionosonde Cyclon-M, operating at ten frequencies from 2.01 to 6.51. MHz was used at the Observatory site. On many heating sessions simultaneous variations of the probing partial reflection signals in Vasil'sursk and backscattered signals in Observatory were observed at the height at 40-100. km below the reflection height of the pumping wave. These observations were correlated with the pumping periods of the Sura facility. Possible mechanisms of the appearance of the disturbance in the lower ionosphere and its effect on the probing radio waves are discussed

Perspective Ground-based Method for Diagnostics of the Lower Ionosphere and the Neutral Atmosphere

We present a new perspective ground-based method for diagnostics of the ionosphere and atmosphere parameters. The method uses one of the numerous physical phenomena observed in the ionosphere illuminated by high-power radio waves. It is a generation of the artificial periodic irregularities (APIs) in the ionospheric plasma. The APIs were found while studying the effects of ionospheric high-power HF modification. It was established that the APIs are formed by a standing wave that occurs due to interference between the upwardly radiated radio wave and its reflection off the ionosphere. The API studies are based upon observation of the Bragg backscatter of the pulsed probe radio wave from the artificial periodic structure. Bragg backscatter occurs if the spatial period of the irregularities is equal to half a wavelength of the probe signal. The API techniques makes it possible to obtain the following information: the profiles of electron density from the lower D-region up to the maximum of the F-layer; the irregular structure of the ionosphere including split of the regular E-layer, the sporadic layers; the vertical velocities in the D- and E-regions of the ionosphere; the turbulent velocities, turbulent diffusion coefficients and the turbopause altitude; the neutral temperatures and densities at the E-region altitudes; the parameters of the internal gravity waves and their spectral characteristics; the relative concentration of negative oxygen ions in the D-region. Some new results obtained by the API technique are discussed

Investigations of Atmospheric Waves in the Earth Lower Ionosphere by Means of the Method of the Creation of the Artificial Periodic Irregularities of the Ionospheric Plasma

We present results of the studies of internal gravity waves based on altitude-time dependences of the temperature and the density of the neutral component and the velocity of the vertical plasma motion at altitudes of the lower ionosphere (60–130 km). The vertical plasma velocity, which in the specified altitude range is equal to the velocity of the neutral component, the temperature, and the density of the neutral atmosphere are determined by the method of the resonant scattering of radio waves by artificial periodic irregularities (APIs) of the ionosphere plasma. We have developed an API technique and now we are evolving it for studying the ionosphere and the neutral atmosphere using the Sura heating facility (56.1 N; 46.1 E), Nizhny Novgorod, Russia. An advantage of the API technique is the opportunity to determine the parameters of the undisturbed natural environment under a disturbance of the ionosphere by a field of powerful high frequency radio waves. Analysis of altitude-time variations of the neutral temperature, the density, and the vertical plasma velocity allows one to estimate periods of atmospheric waves propagation. Wavelike variations with a period from 5 min to 3 h and more are clearly determined

Radio Astronomical and Radiophysical Studies in the Near-Earth Space in the Radiophysical Research Institute

The paper describes possibilities of the experimental investigations of the near-Earth space by the facilities of the Radiophysical Research Institute at Nizhny Novgorod. We describe the experimental equipment, development of the research methods and some recent results

The lower ionosphere response to its disturbances by powerful radio waves

© 2017. The paper presents data from some campaigns at Sura heating facility in 2011-1016. The experiments on probing of the artificial disturbed region of the lower ionosphere were carried out at two observation sites. One of them was located near Vasil'sursk 1. km from Sura facility (56.1°N; 46.1°E) and the other site was located at the Observatory (55.85°N; 48.8°E) of Kazan State University, 170. km to the East. Investigation of the features of the disturbed region of the lower ionosphere based on its diagnostics by the methods of the vertical sounding and oblique backscattering is the main goal of this paper. Ionosphere disturbance was fulfilled by the effect of the powerful radio wave of the ordinary or extraordinary polarization emitted by transmitters of the Sura facility with effective radiated power ERP = 50-120. MW at the frequency of 4.3, 4.7 and 5.6. MHz. Pumping waves were emitted with period from 30. s to 15. min. The disturbed region of the ionosphere in Vasil'sursk was probed by the vertical sounding technique using the partial reflexion radar at the frequency of 2.95 and 4.7. MHz. For the oblique sounding of the disturbed region the modified ionosonde Cyclon-M, operating at ten frequencies from 2.01 to 6.51. MHz was used at the Observatory site. On many heating sessions simultaneous variations of the probing partial reflection signals in Vasil'sursk and backscattered signals in Observatory were observed at the height at 40-100. km below the reflection height of the pumping wave. These observations were correlated with the pumping periods of the Sura facility. Possible mechanisms of the appearance of the disturbance in the lower ionosphere and its effect on the probing radio waves are discussed

The lower ionosphere response to its disturbances by powerful radio waves

© 2017. The paper presents data from some campaigns at Sura heating facility in 2011-1016. The experiments on probing of the artificial disturbed region of the lower ionosphere were carried out at two observation sites. One of them was located near Vasil'sursk 1. km from Sura facility (56.1°N; 46.1°E) and the other site was located at the Observatory (55.85°N; 48.8°E) of Kazan State University, 170. km to the East. Investigation of the features of the disturbed region of the lower ionosphere based on its diagnostics by the methods of the vertical sounding and oblique backscattering is the main goal of this paper. Ionosphere disturbance was fulfilled by the effect of the powerful radio wave of the ordinary or extraordinary polarization emitted by transmitters of the Sura facility with effective radiated power ERP = 50-120. MW at the frequency of 4.3, 4.7 and 5.6. MHz. Pumping waves were emitted with period from 30. s to 15. min. The disturbed region of the ionosphere in Vasil'sursk was probed by the vertical sounding technique using the partial reflexion radar at the frequency of 2.95 and 4.7. MHz. For the oblique sounding of the disturbed region the modified ionosonde Cyclon-M, operating at ten frequencies from 2.01 to 6.51. MHz was used at the Observatory site. On many heating sessions simultaneous variations of the probing partial reflection signals in Vasil'sursk and backscattered signals in Observatory were observed at the height at 40-100. km below the reflection height of the pumping wave. These observations were correlated with the pumping periods of the Sura facility. Possible mechanisms of the appearance of the disturbance in the lower ionosphere and its effect on the probing radio waves are discussed

Sporadic e-layer and powerful HF-radio emission

© 2019 IEEE. Powerful HF radio emission to the Earth's ionosphere can be a reason of complex phenomena, which leads to the generation of artificial ionospheric turbulence. One of the most important components of turbulence is artificial ionospheric irregularities with a transverse dimension from a fraction of a meter to ten or more kilometers. The investigations of their spectral and dynamic characteristics makes possible to study the instabilities properties caused by the powerful radio wave and to study the features of dynamic processes in the ionosphere, and also to determine the possible influence of artificial irregularities to the different ranges radio waves propagation. Therefore, in August 5 2010, a heating experiment was carried out at the SURA heating facilities. The experiment was carried out during evening hours. Observation of generated irregularities occurred at a distance 170 km from the SURA facility at the observatory of Kazan Federal University (near Kazan) with ionosonde Cyclone. The control system of the ionosonde was set to the fast mode of ionograms recording (1 ionogram per minute), which made it possible to observe variations in the amplitude of reflections from the sporadic E-layer (Es). These variations look like synchronous with the heating time. A possible mechanism of the observed effect is discussed

Sporadic e-layer and powerful HF-radio emission

© 2019 IEEE. Powerful HF radio emission to the Earth's ionosphere can be a reason of complex phenomena, which leads to the generation of artificial ionospheric turbulence. One of the most important components of turbulence is artificial ionospheric irregularities with a transverse dimension from a fraction of a meter to ten or more kilometers. The investigations of their spectral and dynamic characteristics makes possible to study the instabilities properties caused by the powerful radio wave and to study the features of dynamic processes in the ionosphere, and also to determine the possible influence of artificial irregularities to the different ranges radio waves propagation. Therefore, in August 5 2010, a heating experiment was carried out at the SURA heating facilities. The experiment was carried out during evening hours. Observation of generated irregularities occurred at a distance 170 km from the SURA facility at the observatory of Kazan Federal University (near Kazan) with ionosonde Cyclone. The control system of the ionosonde was set to the fast mode of ionograms recording (1 ionogram per minute), which made it possible to observe variations in the amplitude of reflections from the sporadic E-layer (Es). These variations look like synchronous with the heating time. A possible mechanism of the observed effect is discussed