Vol 22, No 2 (2019)
- Year: 2019
- Articles: 11
- URL: https://journals.ssau.ru/pwp/issue/view/368
Articles
Investigation of Brillouin scattering parameters in single mode optical fibers
Abstract
The interrogation scheme for fiber optic sensor based on Brillouin scattering is represented. The application of stimulated Brillouin scattering signal formed in etalon optical fiber as reference source realized is proposed. The results of experimental investigations of stimulated Brillouin scattering characteristics depends on pump power and optical fiber parameters are represented.
8-12
Four-wave interaction in a multimode waveguide with a Kerr nonlinearity in a circuit with codirectional pumping waves
Abstract
The quality of image transformation in a four-wave interaction on the Kerr nonlinearity in a multimode waveguide in a circuit with codirectional pumping waves using the method of the point spread function, is analyzed. It is shown that the paraxial waveguide modes completely determine the shape of the point spread function. Increasing the angle between the pump waves leads to the appearance of a “fine” structure of the point spread function. The period of this structure decreases with increasing angle between the pump waves.
13-18
Investigation of the radiation characteristics of the antenna based on a magnetized gyromagnetic resonator with different types of emitters in the form of three-dimensional resonators of different designs
Abstract
In this paper we consider the antenna based on the magnetic gyromagnetic resonator with different types of bulk resonators. The magnetized gyromagnetic resonator is excited through the feeder line by the microwave field and then, in turn, excites the volumetric resonator or the reactor antenna, which radiate an electromagnetic field of rotating polarization into space. Such emitters have a number of unique properties that are provided by the magnetic gyromagnetic resonator: radiation of the circular polarization field; electrical switching of the direction of rotation, high frequency selection and magnetic tuning of the central frequency of radiation. Changing the direction of rotation of the field vector occurs by switching the current in the electromagnet. The shift of the central frequency of radiation can be made by changing the current in the field coil with a wire. In the axial direction, the ellipticity coefficient of the radiation field is close to one. Five types of volumetric resonators and a horn radiator are experimentally investigated. The characteristics of the radiation of the investigated resonators are compared.
19-24
The predictor-corrector method for modelling of self-oscillatory systems
Abstract
In the work physically reasonable algorithm of numerical modeling of nonlinear oscillatory and self-oscillatory systems is offered. The algorithm is based on discrete in time model of the linear oscillator. Nonlinearity is considered by introduction to the oscillator of additional communications by the structural analysis of an initial system. For approximation of a temporary derivative in nonlinear communications it is offered to use the scheme of the prediction and correction. In spite of the fact that theoretically the algorithm has the second order of accuracy, within the numerical experiment with Van der Pol oscillator it shows the best results, than a standard method of the second order – the Heun’s method.
25-29
Nonlinear and frequency properties of interference suppression radio reactors for electric vehicles
Abstract
In the work on the basis of the obtained integral relations, including the integral equations, taking into account the influence of nonlinear magnetic screens on the inductance of multilayer coils depending on the current strength, we study the frequency and nonlinear properties of the inductances of radio reactors of electric transport for interference suppression. Also we study their behavior in the circuit under nonstationary effects.
30-36
Use of the neural network for detection and identification of interference when receiving a spread spectrum signal
Abstract
The main task of the communication system is timely reliable and reliable transmission of messages between subscribers. In the event of interference, the communication system performs its task in accordance with the noise immunity it possesses. At the same time, the mixture of the useful signal, noise and interference, which comes to the receiver input, after the necessary processing, can serve as a source of information on the existing interference in the channel. Information on the presence and nature of interference thus obtained may be useful both for changing the parameters of the radio channel (modulation, frequency, mode) and for an external customer. This article is devoted to the use of neural networks to extract information from the damaged information signals about the nature of the interference that caused such damage.
37-43
Practical research on the creation of an adaptive information and telemetric system for launching promising space rockets
Abstract
The contradiction existing in modern practice of information and telemetric support of launching space rockets has been formulated. A methodical device is proposed, which allows defining a rational program for gathering information while ensuring launches and thereby establishing the correspondence of telemetric information needs to data transfer capabilities. Practical calculations were carried out to determine a rational program for collecting telemetric information during the first session of information and telemetric support for launches of Proton-M launch vehicles from the Baikonur cosmodrome. Mathematical descriptions of the dependencies of the variable parameters on the state parameters of the information-telemetric support system are obtained. Experimental studies and evaluation of the results of calculations to determine the telemetry information collection program were carried out, which showed the efficiency of the developed methodological apparatus and confirmed the advantages of the program approach to the formation of adaptive information collection procedures while ensuring the launch of space rockets.
44-50
Peculiarities of «delta» to «star» equivalent impedances conversion in pi- and T-shaped filter structures
Abstract
The peculiarities of «delta» to «star» equivalent impedances conversion are noted in pi- and T-shaped filter structures. They are taken into consideration for design filters and oscillators resonators. The physical limitations are determined for structures parameters, which lead to these peculiarities. The conversion frequencies are obtained for π- and T-shaped filter structures, where «delta» to «star» equivalent impedances transformation is fulfilled.
51-56
Offset and rotate measurement for video signal superposition
Abstract
In this article the task offset and rotate measurement for video signal superposition was described. The developed algorithm is generalization of Lucas–Kanade model. Another name of this model is optical flow algorithm. The original algorithm allows to rate offsets parameters, but developed algorithm also allows to rate rotate angle. The concept of superposition has based on Taylor series of signal and sinus and cosines replacement on approximate function.
56-61
Method for determining color and chromaticity coordinates according to the original image
Abstract
In this paper, a description is given of the method of colorimetry of an image of an object under investigation according to its photograph or scanned copy. Further, in the text of the article, more briefly, this method will be called photo colorimetry. In general, in the science of color measurement, there are two directions: it is just colorimetry, where color is measured using a colorimeter, and the second is indirect colorimetry, in which color coordinates are calculated using known formulas from the measured optical spectrum or reflected from the object of light or the emission spectrum (for self-luminous objects). Photo colorimetry is based on specially developed software and includes having a computer with a monitor screen running this program. A photo of the object under study is displayed on the computer monitor, which can be a part of the human body (skin), on which some injuries or unwanted objects are visible. The process of measuring the coordinates of color and chromaticity itself is carried out by the method of pixel scanning of the image and the program determines the quantitative values of the primary colors of the monitor screen. Knowing the chromaticity coordinates of the primary colors of the screen (the triangle of color gamut), you can accurately calculate the chromaticity coordinates of the object under study. This is the principle of photo colorimetry.
62-68
Technological method for the design of measuring instruments and systems for operation in previously unknown operating conditions
Abstract
The method of designing radio engineering systems and measuring instruments, which are not affected by disturbing influences, is presented. The method is developed on the base of dual channel principle, formulated by academician Petrov B.N. The technique of practical realization of this method is considered. The advantage of the method is that it allows compensating disturbing influences, nature of which is not known in advance. The efficiency of the method and its implementation technique are illustrated by dual channel measuring bridge circuit. The importance of correct metrological analysis, which confirms efficiency of the method, is shown.
69-76
Регистрационный номер и дата принятия решения о регистрации СМИ: серия ФС 77 - 68199 от 27.12.2016.