Lohvinov Yurii
@ire.kharkov.ua
O.Ya. Usikov Institute for Radiophysics and Electronics of the National Akademy of Sciences of Ukraine
RESEARCH, TEACHING, or OTHER INTERESTS
Physics and Astronomy, Mathematical Physics, Electrical and Electronic Engineering, Computational Theory and Mathematics
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
A. Bukin, , V. Gutnik, Yu. Lohvinov, N. Reznichenko, , , and
National Academy of Sciences of Ukraine (Co. LTD Ukrinformnauka) (Publications)
Subject and Purpose. The article is devoted to the analysis of theoretically and experimentally obtained values of the specific effective sea-scattering surface in the region of super-high-frequencies (SHF). The study is reasoned by the need to know characteristics of the electromagnetic wave scattering from various objects at the modeling stage. The focus is on the choice of backscattering model with a methodology of specific effective scattering surface estimation that takes into account the shadowing effect of the sea surface under given conditions. Methods and Methodology. The study is based on mathematical modeling techniques and is accompanied by the comparison of the modeling results with experiment. Results. Proceeding from the simulation results with the effect of sea-surface shadowing taken into account and relying on the check of consistency with the measured data, a comparison analysis has been performed among theoretical models of specific effective sea-scattering surface calculation at low grazing angles. Conclusion. Analysis has been given to the specific effective sea-scattering surface obtained by the facet and two-scale models and to the values measured by experiment. Quantitative estimates of the specific effective scattering surface have been obtained with the shadowing effect of the sea surface taken into account. Analysis of the quantitative estimates has been carried out.
O. Kostenko, , Yu. Logvinov, Yu. Pedenko, , , and
National Academy of Sciences of Ukraine (Co. LTD Ukrinformnauka) (Publications)
This paper is dedicated to the 90-th anniversary of Vadym Borysovych Razskazovsky, an outstanding scientist in the fields of radio engineering and radio science, holder of the titles and positions like DSc (Engineering), Professor, and Head of the Statistical radio physics department at the O.Ya. Usikov Institute for Radio Physics and Electronics within the Academy of Sciences of Ukraine.
Andrew G. Koshovy, George I. Koshovy, and Yuryi F. Logvinov
IEEE
Two different approaches to generalizations of the classical two-dimensional Sierpinski carpet are presented in correct mathematical sense. The first generalization is based on classical principle of fractal carpet creation. It relates to the change of the fractal creator. In the result a series of two-dimensional self similar fractal square sets can be arisen. The second generalization is reworked on the base of one-dimensional self similar fractal sets with a variable fractal dimension. For all generalized classes of self similar fractal square sets have been presented basic elements of their mathematical analyses.
George I. Koshovy, Yuryi F. Logvinov, and Valentina. I. Karpenko
IEEE
The problem of the plane (electromagnetic or acoustic) wave scattering by a multi level not classical coplanar system of flat impedance strips is analyzed on the base of the singular integral equation method. Considerable attention is focussed on some types of terrible “Devil stairs” functions, corresponding to some self similar fractals with a variable fractal dimension. It is important to have a lot of not classical sets for usage in construction of the coplanar system of impedance strips. The stages of the “Devil stairs” function constructive procedure can be useful for modelling of natural specific irregular zones in regular two-dimensional space. A partial (but important for applications) case of sparsely filled coplanar strip system is analyzed. In this case, the plane wave scattering problems have explicit asymptotical solutions in the closed analytical form.
Victor Gutnik, Valentina Karpenko, Georgii Koshovoi, and Yurii Logvinov
IEEE
The article is devoted to modeling the backscattering of the electromagnetic field on the sea surface in relation to the millimeter and centimeter ranges of radio wavelengths. The relevance of such studies is determined by the need to model the characteristics of sea-based radio systems at the design stage. The aim of the work was to determine the characteristics of the illuminated elements of the underlying surface in relation to the backscattering of radio waves at small slip angles.To achieve this goal, the methods of mathematical and statistical modeling were used. The simulation results were compared with experimental data.Comparison of the lifetimes of the scattering elements of the sea surface and the speeds of their movement with the durations of bursts of the scattered radio signal and Doppler shifts of the radio frequency when moving the diffusers of the electromagnetic field showed the consistency of the results obtained from the simulation with experimental data. The characteristics of the scattering elements of the sea surface are obtained as applied to the backscattering of radio waves at small slip angles. Among them are the probabilities of the illumination of the scattering elements of the surface, their average radii of curvature, as well as the local angles of incidence of the radio wave on the illuminated surface elements.It is shown that with the propagation of radio waves, significant surface shading occurs. This leads to the fact that the electromagnetic field is scattered almost only on the tops of the highest sea waves. In this case, the local angles of incidence of the electromagnetic field on the scattering element of the surface approach 90°. At such local angles of incidence, the illuminated surface element has a very low reflectivity in the opposite direction.
Ihor Deineka, Vladimir Zuykov, Viktor Gutnik, and Yurii Logvinov
IEEE
The relevance of modelling of sea waves is determined by the need to produce a model of sea-based radio performance at the design stage. One of the main parts of these models have the underlying surface. The paper presents a methodology for creating digital models of wind waves with respect to the modeling of propagation over the sea surface. The criteria of choice of the lower and upper boundaries of the spectrum of sea waves, the sampling frequency of the spectrum, the angle and pitch to create random sampling surface.
Alexsandr Bukin, Yurii Logvinov, Victor Gutnik, and Nikolai Reznichenko
IEEE
The article is devoted to modeling the backscattering of the electromagnetic field as applied to the millimeter and centimeter ranges of radio wavelengths. The relevance of such studies is determined by the need to obtain the characteristics of the scattering of electromagnetic waves by various objects at the modeling stage. The aim of the work is to determine the acceptable values of surface discretization in the implementation of known and promising methods for calculating the scattered field.To achieve this goal, methods of mathematical and statistical modeling were used. The simulation results were compared with theoretical studies.The results of numerical simulation of electromagnetic field scattering using the Fresnel-Kirchhoff diffraction formula and a method based on representing the surface in the form of elementary flat areas are considered. Comparison of model and theoretical data on the effective scattering surface for the simplest objects (ball and plane) made it possible to determine the allowable value of the discretization of surfaces during backscattering of electromagnetic fields on them. It is shown that the determination of the field strength by the Fresnel-Kirchhoff method allows one to obtain an effective scattering surface with values that most closely coincide with theoretical data.It is shown that the Fresnel-Kirchhoff method most accurately describes the basic properties of a scattered field. When applying the modeling method, when the surface is represented as a set of flat elements with scattering patterns characteristic of them, it is necessary to normalize the results taking into account theoretical and experimental data.
V. I. Karpenko, G. I. Koshovy, and Yu. F. Logvinov
Begell House
A. S. Glazunov, V. G. Gutnik, M. Yu. Lohvinov, and Yu. F. Lohvinov
Begell House
Yu. F. Logvinov and V. B. Razskazovsky
Allerton Press
V. B. Razskazovsky and Yu. F. Logvinov
Begell House
V. B. Razskazovsky and Yu. F. Logvinov
Begell House
V. B. Razskazovsky, Yu. F. Logvinov, and Yu. A. Pedenko
Begell House
V. B. Razskazovsky and Yu. F. Logvinov
Begell House
V. B. Razskazovsky and Yu. F. Logvinov
Begell House
V.B. Razskazovskiy and Yu.F. Logvinov
IEEE
The errors of measuring of the transmitter azimuth in of Fresnel diffraction approach are calculated. They are created by influence of the large opaque screen with straight or by an uneven border. They is analysed as a function of the transmitter height for the various of the selvedge inclination, she turn and of the amplitudes of sinusoidal roughness of the boundary. Calculations at a straight border are executed in approaching of geometrical theory of diffraction. At a rough border by the method of numeral integration in Kirchhoff approaching.
V. B. Razskazovsky and Yu. F. Logvinov
Begell House
V. B. Razskazovsky and Yu. F. Logvinov
Springer Science and Business Media LLC
V.B. Razskazovskyy and Yu.F. Logvinov
IEEE
On the basis of analysis of extensive experimental data of our researches on the centimeter and millimeter radiowave propagation above a sea and land and results was formulated the conception that heights are single meters above a marine surface with agitation for description of the field it is necessary to utillize a diffraction model but not method of tangent plane (MTP). The lower limit bound of strict application of MTP is determined two criteria: 1. by absence of shadings of elements that reflect to a point observation of the field, its roughnesses; 2. by a limit on the minimum value of the glancing angle from the convex element of roughnesses. After such conclusion obtained from test data analysis, we have applied the proposed DCT based filter to processing real life X-band side look aperture radar (SLAR) images. Thus, we demonstrated that the proposed adaptive DCT-based filter is rather efficient for removing non-stationary noise in selected test applications.
V. B. Razskazovsky and Yu. F. Logvinov
Begell House
Yu. F. Logvinov and V. A. Kirichenko
Begell House
V. B. Razskazovsky and Yu. F. Logvinov
Begell House
Yu. F. Logvinov, V. B. Razskazovsky, and V. A. Kirichenko
Begell House
G. P. Kulemin, V. A. Kirichenko, and Yu. F. Logvinov
Begell House
G. P. Kulemin, V. A. Kirichenko, and Yu. F. Logvinov
Begell House