Features of modification of the earth’s ionosphere by high-power X-mode radio waves and the observed effects

Power Spectra of Ionospheric Scintillations

“…Geometric parameters of plasma irregularities have a substantial influence on the ordinary and extraordinary waves. Increasing characteristic spatial scale of large-scale irregularities phase scintillation index 4 S growth tending to the saturation. Splashes are revealed for different anisotropy factor of elongated largescale irregularities varying orientation angle with respect to the lines of force of geomagnetic field.…”

“…Phase scintillations are usually observed as a phase difference between the antennas of an interferometer system. If rigid irregularities are moving past the radio ray trajectory along the X direction with apparent velocity x V , scintillation level 4 S is computed from the power spectrum [13]; the relationship between the power spectrum of the intensity fluctuations () S P n and the power spectrum of the phase fluctuations () P j n for one dimensional (the irregularities are elongated perpendicular to their direction of motion) weak scattering screen is given by [14]:…”

“…Many papers and reviews are related to the statistical characteristics of scattered radiation and observations in the ionosphere [1,2]. The analysis of the statistical properties of small-amplitude electromagnetic waves that have passed through a plane turbulent plasma slab is very important in many practical applications associated with both natural and laboratory plasmas [3][4][5][6].…”

Study of GNSS-measured ionospheric total electron content variations generated by powerful HF-heating

“…Electron. Special Issues (1994, 1999, 2005, 2008 and the reviews Erukhimov et al (1987), Leyser (2001), Stubbe and Hagfors (1997), Gurevich (2007), Frolov et al (2007), Belikovich et al (2007)) showed that the ponderomotive parametric, thermal (resonant) parametric and self-focusing instabilities develop near the height of reflection of the powerful radio wave. This leads, in particular, to the strong heating of ionospheric plasma in this region and to the generation of artificial irregularities in the ionospheric electron density with the scale sizes from fractions of meter to dozens of kilometers (Gurevich, 2007).…”

“…These irregularities have a considerable effect on the parameters of VHF/UHF/L-band radio waves propagating through the heated area of the ionosphere. The parameters of these irregularities were studied by the methods of field-aligned scattering of VHF/UHF radio waves (Frolov et al, 1997); radio probing of the heated region by radio transmissions from low-orbiting satellites (Erukhimov et al, 1987;Leyser, 2001); ionospheric radio tomography (Tereshchenko et al, 2004;Frolov et al, 2007) and other. Recently, methods for sounding of the heated ionosphere by radio signals from high-orbiting navigational GNSS satellites at frequencies 1.2-1.5 GHz started to develop (Tereshchenko et al, 2008;Milikh et al, 2008).…”