Backscattering at the <Emphasis Type="Italic">E</Emphasis> and <Emphasis Type="Italic">F</Emphasis> layers for the vertical incidence of radio waves on the ionosphere

We present the results of the vertical ionosphere sounding at a frequency of 9.02 MHz using the “Sura” facility. Intense backscatter signals from meteor trails were observed at altitudes 100–130 km. Increased background of the scattered signal, which was about − 100 dB with respect to the mirror-reflected signal, was observed at altitudes of about 190–200 and 270–280 km. According to the Doppler-shift measurements of the scattered-signal frequency, the wind velocity was more than 30 m/s at altitudes 100–130 and 270–280 km and was significantly smaller in the altitude range 190–200 km. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 52, No. 1, pp. 23–27, January 2009.     

Fractal structure of artificial ionospheric turbulence

We show the results of the first experimental studies of the multifractal structure of the developed artificial ionospheric turbulence. As a result of the special multifractal analysis of the recorded amplitudes of signals from the orbital satellites, which were obtained during the experiments on radio tomography of the irregularities excited in the ionosphere by the powerful mid-latitude heating facility “Sura,” it is found that the characteristic multifractal structure of these records is caused by the nonuniform spatial distribution of the small-scale fluctuations of the electron number density in the artificial irregularities of the ionospheric plasma. Comparative analysis is performed for the multifractal spectra of fluctuations of both the amplitudes and energies of signals received from the orbital satellites upon radio transmission probing of the region of artificial ionospheric turbulence by these signals at three observation points located near the “Sura” heating facility and spaced apart to a distance of about 100–150 km. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 51, No. 11, pp. 970–976, November 2008.     

Nulling Phenomenon of the New Radio Pulsar J0810+37 at a Frequency of 111 MHz

Pulsar J0810+37 with a period of 1.2483 s is detected at a frequency of 111 MHz during the pulsar search at the Big Scanning Antenna (BSA) radio telescope of the Lebedev Physical Institute [1]. In this paper, we present the results of the detailed study of radio emission from J0810+37 which exhibits a rare nulling effect of different durations in a very wide time interval with an average nulling fraction in “switch-on” days 〈NF〉 = 38%; considering “switch-off” days, 〈NF〉 = 74%, since radio emission from this source is interrupted on average by 2–3 days, and then it again revives on average for 1–2 days. The “switch-off” periods reach 7 days.     

First experience on spatial discrimination of large-scale natural elf interference on the example of two-point measurements of the magnetic field of an artificial ionospheric source

We present the results of an experiment on the generation of extremely low-frequency (ELF) electromagnetic fields at frequencies near the first Schumann resonance upon the ionosphere modification by modulated powerful radio emission. The reception was performed at two sites spaced by 14 km in the distance from “SURA” facility. It was found that the natural noise at different reception sites is highly correlated, which allows one to achieve the noise suppression by about an order of magnitude by subtracting the measurement results. We demonstrate the opportunities of spatial discrimination of the interference upon the two-site reception of the “small-scale” field of an artificial ionospheric source. The directions of future studies and possible applications are discussed. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radio.zika, Vol. 49, No. 12, pp. 1030–1042, December 2006.     

Seasonal behavior of middle-latitude short-wave mesospheric radio echoes

Using the radar of the “Sura” facility, we studied the diurnal and seasonal behavior of mesospheric middle-latitude short-wave radio echoes. It was, found that the diurnal dependence of the intensity of reflected signals is mainly determined by the solar illumination of the mesosphere, i.e., by photoionization intensity. We revealed an almost permanent and season-independent presence of a thin turbulent layer at altitudes of 82 to 84 km whose radio echoes are maximal in summer and winter and much weaker in spring and fall. Sporadic summer radio echoes with increased intensity, which are observed at somewhat greater (by 2 to 4 km) altitudes, apparently correspond to the phenomenon of mesospheric summer echo (MSE) observed in the VHF range. The material of the article has been reported at the IIIrd International School on Space Plasma Physics. Radiophysical Research Institute, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebmykh Zavedenii, Radiofizika, Vol. 41, No. 10, pp. 1248–1257, October 1998.     

Computer model of a meteor radio channel

A computer model of a meteor radio channel is presented. The model is based on the Monte-Carlo method. The possibility of effective choice of the model parameters is proved. The simulation results agree well with the experimental data obtained in meteor radio lines with lengths of 240, 700, and 1100 km.State University, Kazan. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 38, No. 11, pp. 1177–1186, November, 1995.     

Characteristics of the spatial spectrum of plasma irregularities excited at mid-latitudes by the high-power “Sura” facility

We present the results of analysis of the spectra of amplitude scintillations at a frequency of 150 MHz and a difference phase at frequencies of 150 and 400 MHz, which were obtained in the experiment on radio tomography of artificial ionospheric turbulence (AIT) excited by the mid-latitude high-power “Sura” heating facility [1]. We used the data on radio probing of the AIT region at a frequency of 150 MHz by signals from artificial satellites in near-polar circular orbits at altitudes of 1000 km above the Earth’s surface. The signals were received simultaneously at three spaced apart points located at distances of about 100–150 km from each other along the projection of the satellite trajectory onto the Earth’s surface. The analysis of the data shows that in the range of scales smaller than 0.5–1.0 km across the geomagnetic field, the AIT spatial spectrum can be described by the power-law function with the spectral index p_⊥ = 1.7–2.5. For irregularities with the same transverse scales, the spectral index in the direction of the magnetic field amounts to p_‖ = 5–7. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 50, No. 8, pp. 722–730, August 2007     

Two-particle correlations in 1D-lattice systems with δ-interactions

The problem of two interacting particles in finite closed and open chains is solved by the Lifshitz method. The “density-density” correlation function, the dependence of the “surface” energy on the two-particle interaction energy and number of links in the chain, and the two-particle distribution on the chain are found and the nature of the ground state is clarified. Fiz. Tverd. Tela (St. Petersburg) 40, 366–370 (February 1998)     

Some results of measuring the characteristics of electromagnetic and plasma disturbances stimulated in the outer ionosphere by high-power high-frequency radio emission from the “Sura” facility

We present the results of measuring the characteristics of electromagnetic and plasma disturbances at altitudes of about 700 km, obtained by using the onboard equipment of the French microsatellite DEMETER during its passage through the magnetic tube resting upon the region of intense generation of artificial ionospheric turbulence created due to modification of the ionospheric F₂ region by high-power radio emission from the “Sura” facility. It is shown that an artificial density duct emerging from the disturbed region and extending to the Earth’s magnetosphere can be formed. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 50, No. 8, pp. 709–721, August 2007.     

VLBI studies of the solar-wind plasma irregularities at 18 and 92 CM wavelengths in 1994–1996

We discuss the capabilities of VLBI studies of irregularities of the solar-wind plasma using multi-element radio interferometric facilities. We analyze the data obtained during international VLBI experiments at decimeter wavelengths (92 and 18 cm) in 1994–1996 and supposed that the irregularities have a “stream” structure. The “streams” are strongly elongated in the solar-wind direction (longitudinal size of about a few hundred thousand kilometers) and have the transverse size of about 0.5–2.0 thousand kilometers. The irregularities inside a single “stream” are almost isotropic. We discuss the restrictions imposed on operation of decimeter VLBI systems due to effects of the interplanetary medium. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 43, No. 3, pp. 197–206, March, 2000     

Method of cosmic radiation recording in spectral lines

We propose a method for recording of energy parameters of cosmic radio emission in spectral lines, differing in the principle of amplitude calibration of the reception-measurement channel. This method does not require the use of additional channels of signal-power measurement and reduces the source observation time required for extraction of a signal from noise and its recording. Radio emission is recorded using a standard high-sensitivity receiver of the RT-32 radio telescope and a digital spectrum analyzer based on the fast Fourier transform. We consider two variants of the recording system: a variant with off-shelf general-purpose spectrum analyzers (e.g., NI-5620), which use PC processors, and a variant with high-speed specialized analyzers based on programmable logical devices. The system with an XC4VLX25 integrated-circuit analyzer is operated in a frequency band of up to 32 MHz and has a minimum response time, which makes it possible to minimize the source observation time. The spectrum recording system developed at the Institute of Applied Astronomy of the Russian Academy of Sciences and “Radioelectronic Technological Equipment Ltd” and supported by a project of the Russian Science Agency was put into service in the “Svetloe” radioastronomical observatory in 2006. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 51, No. 9, pp. 777–788, September 2008.     

Results of Determining the Electron Number Density in the Ionospheric E Region from Relaxation Times of Artificial Periodic Irregularities of Different Scales

We present the first results of determining the electron number density in the ionospheric E region by a novel technique based on the creation of artificial periodic irregularities when the ionosphere is affected by powerful radio emission at two frequencies. Using the results of the measurements performed in October 2006 during heating of the ionosphere by the “Sura” facility radiation at frequencies 4.7 and 5.6 MHz, we obtained the electron number density profiles in an altitude range of 100 to 110 km. Features of the procedure of measurement and calculation of the electron number density are described in detail. It is shown that the method can be used for a study of the irregular structure of the lower ionosphere. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 51, No. 6, pp. 477–484, June 2008.     

Bell’s Theorem,Many Worlds and Backwards-Time Physics: Not Just a Matter of Interpretation

The classic “Bell’s Theorem” of Clauser, Holt, Shimony and Horne tells us that we must give up at least one of: (1) objective reality (aka “hidden variables”); (2) locality; or (3) time-forwards macroscopic statistics (aka “causality”). The orthodox Copenhagen version of physics gives up the first. The many-worlds theory of Everett and Wheeler gives up the second. The backwards-time theory of physics (BTP) gives up the third. Contrary to conventional wisdom, empirical evidence strongly favors Everett-Wheeler over orthodox Copenhagen. BTP allows two major variations—a many-worlds version and a neoclassical version based on Partial Differential Equations (PDE), in the spirit of Einstein. Section 2 of this paper discusses the origins of quantum measurement according to BTP, focusing on the issue of how we represent condensed matter objects like polarizers in a model “Bell’s Theorem” experiment. The backwards time telegraph (BTT) is not ruled out in BTP, but is highly speculative for now, as will be discussed. The views herein are not anyone’s official views, but this does constitute work produced on government time.     

The “Sura” facility: Study of the atmosphere and space (a review)

We present a short review of research using “Sura,” a multipurpose radio facility of the Radiophysical Research Institute of Nizhny Novgorod, which is aimed at studying space, the atmosphere, the Earth’s crust, and radio wave propagation and at developing new methods for diagnostics and monitoring of the environment. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 50, No. 7, pp. 545–576, July 2007.     

Modification of the earth’s ionosphere by high-power HF radio emission: Artificial periodic inhomogeneities and the sporadic <Emphasis Type="Italic">E</Emphasis> layer

We present the results of new studies of the sporadic E layer in the case of heating of the ionosphere by high-power HF radio emission. The measurements were performed at the “Sura” heating facility. Ionosphere was modified by high-power radio emission from the “Sura” facility and was sounded by the probing radio waves of the same frequency and mode. The heating of the ionosphere resulted in the formation of artificial periodic inhomogeneities, and an increase in the intensity of all signals scattered by the D, E, and F regions and the sporadic E layer by 5–20 dB was observed. The increase was observed during heating of the ionosphere by each magnetoionic component, but was smaller for heating by an ordinary-mode wave. This effect was resonant and disappeared as a result of the frequency detuning down to 85 kHz. During the ionospheric modification, the signal-intensity increased due to modulation of the natural profile of the electron number density by the artificial periodic structure. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 50, No. 8, pp. 695–708, August 2007.     

Radio-acoustic sounding of the ionosphere

We present the results of first experiments on radio-acoustic sounding of ionosphere at the altitudes from 70 to 85 km. The sounding was performed in autumn 2006, using a horn acoustic emitter and a radar on the basis of the “Sura” facility. The emitter had an acoustic power of about 1 kW and operated in the chirp-modulation regime with frequency variation from 15.9 to 18.4 Hz. The radar transmitter operated in the pulse regime at a frequency of 9 MHz and had an average power of 30 kW. The power of the radio signal scattered from a sound wave in the ionosphere did not exceed 10⁻¹⁶ W, and the measured values of the temperature in the scattering region ranged from 190 to 225 K. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 52, No. 2, pp. 128–133, February 2009.     

Sura-wind radar: Studies of nonlinear effects using VHF-wave occultion of the ionosphere

We present experimental results on reception of VHF signals of the transmitting facility “Sura” of the Radiophysical Research Institute by the NASA spacecraft WIND. The experiments were performed during daytime during the summer seasons 1997–1998. The dependence of power and spectral characteristics of the VHF radio waves on the power of the sounding radiation is analyzed. We find that, in a wide range of effective powers of the VHF radiation from about 40 kW to 160 MW, the phenomena observed in the radiation received onboard WIND (such as focusing, scintillations, or frequency deviations of signals) does not usually depend on the operation mode of the “Sura” facility. At the same time, broadening of the radiation pattern of the facility and decrease of the mean level of the received signal by about 6 dB toward the direction of maximum of the radiation pattern were observed at the peak radiation power of the facility. The experimental results are compared to present concepts on effects of self-focusing instability and nonlinear defocusing of VHF radio waves in the ionospheric plasma. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 42, No. 8, pp. 799–809, August 1999.     

Oblique chirp sounding of the modified ionosphere. Experiment and simulation

We present the results of experimental studies of the influence of artificial ionospheric disturbances on HF signals used for oblique sounding of the disturbed volume. The measurements have been performed by a chirp ionosonde over the path Yoshkar-Ola-“Sura”-niznhy Novgorod with length 234 km. We found the 2F2 mode to disappear (attenuation up to 20 dB) when the ionosphere is influenced by a vertical powerful radiation in the ordinary mode with long (15 min each) heating and pause intervals. Modeling of the observed effect was carried out. The calculations agree well with experimental data if the traveling ionospheric disturbances (TID) with vertical and horizontal scales l_z∼20 km and l_x∼50 km, respectively, and the relative disturbance of the electron density δN∼0.2–0.3 are amplified (generated) during the ionosphere heating. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 42, No. 4, pp. 303–313, April 1999.     

Detecting hidden spatial and spatio-temporal structures in glasses and complex physical systems by multiresolution network clustering

We elaborate on a general method that we recently introduced for characterizing the “natural” structures in complex physical systems via multi-scale network analysis. The method is based on “community detection” wherein interacting particles are partitioned into an “ideal gas” of optimally decoupled groups of particles. Specifically, we construct a set of network representations (“replicas”) of the physical system based on interatomic potentials and apply a multiscale clustering (“multiresolution community detection”) analysis using information-based correlations among the replicas. Replicas may i) be different representations of an identical static system, ii) embody dynamics by considering replicas to be time separated snapshots of the system (with a tunable time separation), or iii) encode general correlations when different replicas correspond to different representations of the entire history of the system as it evolves in space-time. Inputs for our method are the inter-particle potentials or experimentally measured two (or higher order) particle correlations. We apply our method to computer simulations of a binary Kob-Andersen Lennard-Jones system in a mixture ratio of A₈₀B₂₀ , a ternary model system with components “A”, “B”, and “C” in ratios of A₈₈B₇C₅ (as in Al₈₈Y₇Fe₅ , and to atomic coordinates in a Zr₈₀Pt₂₀ system as gleaned by reverse Monte Carlo analysis of experimentally determined structure factors. We identify the dominant structures (disjoint or overlapping) and general length scales by analyzing extrema of the information theory measures. We speculate on possible links between i) physical transitions or crossovers and ii) changes in structures found by this method as well as phase transitions associated with the computational complexity of the community detection problem. We also briefly consider continuum approaches and discuss rigidity and the shear penetration depth in amorphous systems; this latter length scale increases as the system becomes progressively rigid.