IKBFU's Vestnik

2013 Issue №4

Investigation of distortions of the chirp signals in the neighborhood of critical frequencies of ionospheric plasma

Abstract

Numerical experiments are performed to investigate the dispersion distortions of chirp pulses propagating in the ionosphere with taking the three-dimensional non-uniformity, anisotropy, and dispersion of ionosphere in dependence on geophysical conditions into account. Propagation, absorption,and the time delay of ordinary and nonordinary waves are analased.

Download an article

The dynamics of ground-level aerosol lidar observation in Kaliningrad

Abstract

The paper presents an analysis of the spectra of atmosphere aerosol variations and variations Total Electron Content in the ionosphere (TEC). Monitoring of atmospheric aerosol performed with using of the two-wavelength (532, 1064 nm) atmospheric lidar (LSA-2S). Ionospheric TEC parameter determined from the observation of the navigation satellites signals GLONASS (Leica1200). The observations in the lower atmosphere and ionosphere were executed simultaneously in the period February — March 2012. Analysis of the observations showed that during the period of solar terminator passing in the lower and upper atmosphere, there are variations of parameters with periods close to the period Väisälä — Brunt in the lower atmosphere. It is assumed that such disturbances are excited in the lower atmosphere and propagate into the upper atmosphere. It is assumed that the disturbances with periods close to the period of the Väisälä — Brunt can take an important part in the implementation of dynamic relationships of lower and upper atmospheric layers

Download an article

Application of radio physical methods for diagnostics of functional properties of magnetic tunnel transitions

Abstract

The article presents the main investigation results of the structural and magnetic parameters of a series of samples formed on single-crystal (MgO) and on amorphous substrates Si/SiO2 structures. Were assessed quality indicators such as the paramagnetic phase, the presence of impurities, and an analysis of the functional properties through continued Gilbert was done. The radiophysical methods features for the diagnosis of prospective structures were shown.

Download an article

The solution of a problem of detection of a signal at vertical sounding of an ionosphere

Abstract

In the real work the solution of a problem of determination of parameters of the radio impulse reflected from an ionosphere is considered. The noise component, and also the multibeam structure of a signal arising at formation two magnetoionic component is thus considered. Expression for definition of probability of reception of a radio impulse in these conditions is received.

Download an article

Ionospheric station of vertical sounding of an ionosphere «Vector»

Abstract

The structure of station of vertical sounding "Vector" and results of correlation data processing is presented. For vertical sounding of an ionosphere the difficult signal in the form of the М sequence, containing 16 positions is used. Ways of further modernization of station are shown. Them treat expansion of opportunities of determination of parameters of signals at twofold reflection from an ionosphere.

Download an article

Use of difficult signals at vertical sounding of an ionosphere

Abstract

In the real work questions of sounding of an ionosphere are considered by difficult signals. Efficiency of use of signals with big base on an alignment with signals with base about 1 is estimated. It is shown that when using difficult signals it is possible to lower significantly capacity at preservation of invariable level of permission.

Download an article

Research of process in bistable system when passing the mix of the harmonious signal and «white» noise

Abstract

In the work the mechanism of compound harmonic signal and noise through the bistable system which role carries out Schmitt's trigger is considered. Dependence of signal-to-noise ratio on different factors is shows. Necessary conditions for ensuring increase of the signal-to-noise ratio at the output of the system are defined. The decision on practical implementation of the effect in electronic circuits of various purposes is submitted.

Download an article

About opportunity of integration of antenna systems into bearing constructive elements of mobile objects

Abstract

Possibility of use in antenna systems of an additional dielectric layer is considered. At the expense of use of the phenomenon of «shortening» of an electromagnetic wave in environments with high dielectric permeability there is a possibility of creation of the integrated antennas on a surface of bearing designs of mobile objects.

Download an article

Evaluation of noise stability reception FSK-signal by quadrature reception device

Abstract

A comparative evaluation of the model and the theoretical curves of the probability of bit error at the output of the unbounded receiving device of MSK-signals in presence of white Gaussian noise. It is shown that this method of signal processing provides declared value of noise stability in critical values of SNR region compared with existing demodulators.

Download an article