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Том 62, № 5 (2019)
- Год: 2019
- Статей: 6
- URL: https://ogarev-online.ru/0033-8443/issue/view/15182
Article
Influence of Horizontal Ionosphere Nonuniformity on the Spatial Distribution of Ultralow-Frequency Magnetic Fields from Ground-Based Sources
Аннотация
A significant difference was found in the amplitude and polarization spectra of ULF magnetic noise at stations with a base of 120 km during periods of absence of regional thunderstorm activity. A simultaneous analysis of low-frequency data and ionosonde data allowed us to conclude that the difference in the main parameters of the polarization spectrum at two stations is due to the appearance of sporadic Es layers having a nonuniform horizontal intensity distribution with characteristic scales of the order of the base between stations. A difference in the depth of variations in the polarization parameter ε was also found during the ionosphere recovery after magnetic storms. It could be related with Es layers, which had not only a nonuniform intensity distribution, but were also located at different altitudes. A difference was found in the frequency scales of the spectral resonance structure during recording of time variations of its fundamental frequencies. Numerical calculations of the parameter ε with specifying model Es layers and electron-density profiles corrected at the altitudes of the ionospheric F layer adequately explained the observed difference in the magnetic noise spectra and allowed us to determine the altitudes at which the horizontal ionospheric irregularity existed. The studies were carried out on the basis of records of horizontal magnetic components at Radiophysical Research Institute midlatitude observatories Novaya Zhizn (56° N, 45.74° E) and Staraya Pustyn (55.66° N, 43.63° E, 120 km east of the first reception point).
311-325
A Study of the Density Variations of Mesospheric Ozone in the Case of Ionospheric Perturbation by The “Sura” Facility Radiation with Simultaneous Diagnostics of Ionospheric Plasma
Аннотация
We present the results of microwave observations of atmospheric radiation in the ozone line in the case of ionospheric perturbation by powerful high-frequency radio emission from the “Sura” facility in September 2016. The atmospheric-radiation spectrum in the ozone line was measured by the method of the ground-based microwave radiometry. The state of the lower ionosphere was simultaneously diagnosed in the altitude range 50–130 km using the method of resonant scattering of radio waves by the artificial periodic irregularities of ionospheric plasma. A decrease in the intensity of the microwave atmospheric radiation in the ozone line was observed. The results of measurements of the amplitude and phase of the signal scattered by artificial periodic irregularities demonstrated a perturbation of the parameters of the lower ionosphere when it was heated by high-frequency radiation.
326-341
Energy Spectra of Electron Beams and the Possibility of Double-Stage Energy Recuperation in a Double-Beam Terahertz Gyrotron
Аннотация
We study theoretically the possibilities of double-stage energy recuperation in a double-beam terahertz gyrotron. Numerical modeling, which was performed for a gyrotron producing radiation with a frequency of 0.78 THz and operating at the second cyclotron-frequency harmonic at the TE8.5 mode, demonstrates the possibility of spatial and energy separation of electron beams. This makes it possible to implement a double-stage recuperation scheme. The found energy spectra of electrons suggest an increase in the gyrotron efficiency by 3.5–4 times.
342-347
Nonlinear Wave Processes in Polycristalline Solids with Hysteresis-Loss Saturation and Relaxation
Аннотация
Using the perturbation method, we study the processes of nonlinear propagation of the initially harmonic elastic waves in micro-inhomogeneous media, namely, polycrystalline solids with hysteresis-loss saturation and relaxation. The media with the basic hysteresis types, elastic and inelastic, are considered. The efficient nonlinearity parameters of such media are determined for the processes of self-action of a quasiharmonic wave and generation of its higher harmonics.
348-360
Extreme Probabilistic Characteristics of the Measurement Disambiguation in Multiscale Phase-Measuring Systems
Аннотация
We determine the upper limit on the correct measurement disambiguation probability in multiscale phase-measuring systems in which all scales are ambiguous. The measured value is estimated by the maximum likelihood method from the total of measured phase differences supplemented by an algorithm for rejecting (erasing) measurement results with anomalously large errors. Errors that exceed one-half of the main lobe of the likelihood function are considered anormalously large. The results are obtained by the methods of linear algebra with a geometric interpretation of the measurement disambiguation process in the space of total phase differences. The method was applied to phase direction finders, but can easily be adapted to other types of multiscale phase radio systems.
361-368
On the Region of Existence of a Discrete Lorenz Attractor in the Nonholonomic Model of a Celtic Stone
Аннотация
In this work, we consider the problem of existence of discrete Lorenz attractors in the nonholonomic model of a Celtic stone. To this end, the main local and global bifurcations leading to the appearance and destruction of the attractors are studied in two-parameter families of such models of certain types. The corresponding bifurcation diagram, in which the region of existence of a discrete Lorenz attractor is shown and its boundaries are described, is obtained on the plane of the governing parameters (the angle of dynamic asymmetry of the stone–the total-energy value). The similarities and differences in the scenarios of the appearance of a discrete Lorenz attractor in the nonholonomic model of a Celtic stone and attractor in the classical Lorenz model are found.
369-384