# 4 2021

• M. A. Isaev, G. I. Linets
  Method for recovering estimation of the motion parameters of an unmanned aerial vehicle when identifying the fact of interference on the on-board receiver of satellite navigation signals
• Abstract
  • Relevance. Navigation tasks on the overwhelming number of small unmanned aerial vehicles (UAVs) are solved by combining signals from a satellite radio navigation system (SRNS) and an inertial navigation system. An effective method for countering UAVs is the creation of zones of local suppression of signals from navigation satellites, which distorts the assessment of UAV motion parameters performed by the on-board computer in real time, and as a result, deviates the actual flight path from the specified one. Known works describing the algorithms for the operation of UAVs in a jamming environment do not consider the time interval between the actual onset of jamming on the SRNS receiver and the identification of this fact by an on-board computer, which does not allow ensuring the accuracy of maintaining a given flight path required for UAV operation when overcoming jamming zones. The aim of the work is to increase the accuracy of the estimation of motion parameters when overcoming the zones of interference by eliminating inaccurate data of the on-board module of the SRNS from the navigation system contour for the time interval between the actual start of the interference and the identification of this fact by the on-board computer. Methods. The problem was solved by buffering the residual vector, which is the difference between the estimated state of the UAV motion parameters using a mathematical model and the parameters obtained from the onboard module of the SRNS. When performing a flight task under conditions of reliable signals from navigation satellites, the proposed method buffers the residual vector in a sliding window mode. After identifying the fact of interference, the data of the SRNS module are not used, and the buffered value of the residual vector is subtracted from the estimate of the state space vector, thereby eliminating unreliable SRNS data and restoring the accuracy of the estimation of the UAV motion parameters. In the future, before leaving the zone of interference, the inertial dead reckoning method is used to update the parameters of the UAV movement. Novelty. Element of novelty in this work is the procedure for buffering the residual vector to exclude inaccurate data of the on-board SRNS module after identifying the fact of interference for the time period necessary for the on-board computer to identify the fact of interference. Result. The use of the proposed method in the navigation system of the UAV "Albatros NCFU" made it possible to ensure the accuracy of positioning of the UAV when overcoming interference zones no worse than 3.337 m for the northern and 0.869 m for the eastern directions after identifying the fact of interference, which reduced the error by 55.757 m and 5.273 m respectively. Practical relevance. The solution of the problem, taking into account the specified features, made it possible to reduce the positioning error of small UAVs and ensure its invariance for the time interval required by the onboard computer to determine the fact of interference. The presented method is implemented in the C programming language in accordance with the C11 standard and is suitable for use in embedded systems that are characterized by low computing resources, RAM and ROM.
• Key words
  • unmanned aerial vehicle, UAV, UAV, inertial navigation system, interference effect, GNSS receiver, Kalman filter
• Reference
  • Isaev M. A., Linets G. I. Method for recovering estimation of the motion parameters of an unmanned aerial vehicle when identifying the fact of interference on the on-board receiver of satellite navigation signals. Systems of Control, Communication and Security, 2021, no. 4, pp. 72-98. DOI: 10.24412/2410-9916-2021-4-72-98 (in Russian).

• A. G. Studenikin, I. B. Kryzhko, A. B. Tokarev, A. V. Ashihmin, A. A. Fateev
  Algorithm for preliminary identification of radio signals with spectral masks
• Abstract
  • Purpose. The implementation of broadband radio monitoring involves determining the belonging of observed radio emissions to specific data transmission standards. The procedures for full-scale verification of such an affiliation are very laborious, so it is advisable to use a two-stage identification procedure, at the initial stage of which the most plausible are identified among possible hypotheses about compliance of radiation with standards, and at the final stage, after a detailed recheck of these hypotheses, final decisions are made. The purpose of the work is to develop an algorithm for preliminary identification of signals, which allows us to hypothesize that the observed radio emissions belong to different standards only on the basis of broadband spectral diagrams accumulated over a wide range of samples. The formation of accumulated spectral diagrams is an integral part of the procedure for detecting radio emissions and therefore their use does not increase the computational complexity of signal processing in radio monitoring systems. Novelty. The proposed identification algorithm takes into account the possibility of significant deformation of the accumulated signal spectra due to interference distortions and uses the combination of known statistics (modified correlation coefficient of fragments of accumulated spectral diagrams with spectral masks of detected emissions) and author's approaches to search for target signals. The latter include control of compliance of stretching degree of the normalized reference spectra (spectral masks) with physical expectations, estimation of mismatch between the spectra of the received signal and spectral masks, as well as specialized check of integrity of the identified spectra. Results. The practical testing of the proposed algorithm on real signals demonstrates the stability of its operation and the high reliability of identifying signals even with significant interference distortions of their spectra in a complex urban radio setting. Comparative testing shows that the proposed algorithm is operational at a signal-to-noise ratio 5-10 dB less than the values required for other known algorithms presented in the technical literature. Practical relevance: the implementation of the developed algorithm provides radio monitoring systems with a reduction in the cost of time and computing resources to determine the belonging of detected signals to specific data transmission standards.
• Key words
  • radio monitoring systems, signal identification, accumulated spectrum, spectral mask of emission, spectral similarity measures, Spectral Correlation Coefficient, Spectral Angle Mapper, Spectral Information Divergence
• Reference
  • Studenikin A. G., Kryzhko I. B., Tokarev A. B., Ashihmin A. V., Fateev A. A. Algorithm for preliminary identification of radio signals with spectral masks. Systems of Control, Communication and Security, 2021, no. 4, pp. 10-39. DOI: 10.24412/2410-9916-2021-4-10-39 (in Russian).

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• A. V. Ashikhmin, A. D. Vinogradov, A.M. Rembovskij, V. А. Sladkikh
  Method for single-position positioning of radio emission sources using an on-board radio direction finder of an unmanned aerial vehicle of a helicopter type
• Abstract
  • Problem statement: Nowadays "low-power" ground-based radio emission sources (RES) with directional antennas and a limited time of radiation of radio signals are increasingly used. For such RES the efficiency of the existing ground-based mobile radio monitoring equipment, which has a limited height of placement of antenna devices, is significantly reduced. Ground-based multipoint positioning systems also become practically inoperable, since the probability of simultaneous electromagnetic availability of ground-based RES from several (at least two) reception points of multipoint positioning systems becomes extremely low. Accordingly, the development of methods for locating sources through the use of a helicopter-type unmanned aerial vehicle (HT UAV), which can signi­ficantly increase the coverage area with the detection and determination of the coordinates of the IRI, becomes very relevant. The aim of the work is to develop a method for single-position radio emission sources positioning using a single-position azimuth-elevation system located on a helicopter-type unmanned aerial vehicle. It is also planned to substantiate the direction-finding antenna array structure and the principles of constructing local goniometric navigation systems that provide the possibility of radio monitoring station operation on HT UAV. Novelty: in contrast to analogs in the proposed method the RES positioning lines are located not on the surface of the Earth, but in free space. This makes possible not only multi-position, but also single-position coordinates definition of ground-based RES. At the same time, the accuracy of RES coordinates estimation is increased and computational costs are reduced. Result: the implementation of the proposed method in the developed wide-range radio monitoring station on light-class UAVs provides the possibility of more accurate determination of the locations of single-position RES in comparison with known ground-based radio monitoring stations or stations located on UAVs. This improvement is maintained even if the global satellite navigation signals are not available. Compared to ground-based radio monitoring stations with multipoint positioning the radius of the working area increases by at least 4 times. Practical relevance: the proposed method based on HT UAVs can be used for single-position and multi-position determination of the ground-based radio emission sources coordinates.
• Key words
  • radio emission source, helicopter-type unmanned aerial vehicle, determination of coordinates, radio monitoring station
• Reference
  • Ashikhmin A. V., Vinogradov A. D., Rembovskij A. M., Sladkikh V. А. Method for single-position positioning of radio emission sources using an on-board radio direction finder of an unmanned aerial vehicle of a helicopter type. Systems of Control, Communication and Security, 2021, no. 4, pp. 40-57. DOI: 10.24412/2410-9916-2021-4-40-57 (in Russian).

• V. V. Allakin, N. P. Budko, N. V. Vasiliev
  A general approach to the construction of advanced monitoring systems for distributed information and telecommunications networks
• Abstract
  • Task statement: based on a review of existing technologies and existing monitoring systems for public information and telecommunications networks, as well as an analysis of the scientific and methodological apparatus for evaluating the time series of observed metrics, to develop general requirements and approaches to building promising network monitoring systems and to develop a methodology for predicting (preventive identification) of abnormal situations based on the results of monitoring the functional state of network elements. The purpose of the work: to develop a general approach to the formation of methods for predicting the state of connections on a public information and telecommunications network, as well as its network devices. Methods used: methods of multidimensional data analysis; methods of cluster analysis; topological methods of time series analysis; methods of behavioral analytics; symbolic representation of time series; network monitoring technologies Site/System Reliability Engineering, as a set of engineering practices that support reliable and trouble-free operation of applications in the present and future; Operation Support Systems, as a technology for supporting operations; methods of system analysis, structural synthesis, forecast theory, diagnostic theory, classification theory. The novelty of the work: to increase the stability and reliability of a controlled heterogeneous information and telecommunications network, the key architectural principle of designing its monitoring subsystem is the principle of distribution and decentralization. Preventive identification of abnormal states of network elements (in the form of devices, channels, paths and routes) is proposed to be carried out by identifying "forbidden" code combinations when observing time series, which are processed by symbolic dynamics methods borrowed from bioinformatics, previously used in the analysis of complex nucleotide genomic sequences, as well as by introducing a special monitoring mode, when, when identifying a pre-failure technical condition, the accuracy of the survey by the monitoring server of the network element is significantly increased in order to timely take preventive control actions on the network infrastructure and prevent the failure of the network element or the occurrence of an accident on the network. A method for classifying the state of network elements is proposed, consisting of a stage of training a classifier based on an EM algorithm, as well as a stage of directly classifying the type of technical condition. Result: the paper proposes a generalized architecture for building promising network monitoring systems, as well as a general subject-object model of it in the form of "entity-connection". The functions of the network monitoring subsystem and the monitoring server as its key element are defined. A variant of the monitoring server structure is considered. The assigned monitoring objects are defined, as well as a list of metric data collected from them from the point of view of the functional performance of the network. The method of symbolic representation of time series is chosen, on the basis of which the entropy of code words describing the time series of the observed metric of a functioning network element is estimated, and an algorithm for identifying its anomalous state on a time series of parameters is developed, consisting of four stages: the preliminary stage, the stage of encoding time series, the stage of identifying the type of technical condition of the network element and the final stage. Practical significance: A general approach to the construction of an algorithm for the functioning of promising network monitoring systems has been developed.
• Key words
  • time series, monitoring decentralization, information and telecommunications network, network monitoring subsystem, monitoring server
• Reference
  • Allakin V. V., Budko N. P., Vasiliev N. V. A general approach to the construction of advanced monitoring systems for distributed information and telecommunications networks. Systems of Control, Communication and Security, 2021, no. 4, pp. 125-227. DOI: 10.24412/2410-9916-2021-4-125-227 (in Russian).

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• S. I. Makarenko, A. I. Karutin
  Prospects and problematic issues of ensuring the interoperability of integrated space systems
• Abstract
  • Relevance. In the present, integration is the most relevant direction of the space systems development. In particular, there is a tendency that the existing satellite communication systems (SATCOM), the Earth observation satellites systems (EOSS) and the global navigation satellite systems (GNSS) will be combined into a single integrated space system. Therefore, the relevance of ensuring interoperability in such the integrated space system is growing. The goal of the paper is a conceptual description of the interoperability approach, presented in the Russian standard GOST R 55062-2012, for a new type of an information system - the integrated space systems, as well as justification of development directions for the technical ways of combining the space systems that previously functioned separately. Results. There are the interoperability barriers, a new approach to ensuring the interoperability of integrated space systems based on GOST R 55062-2012 and the further research directions of the of integrated space systems development in the paper. The novelty elements of the paper are the use of the well-known theoretical approach to interoperability, presented in the Russian standard GOST R 55062-2012, in order to form technical methods of combining the space systems. Practical significance. The material of the paper can be used by designers and scientists for further research in the interoperability field of space systems, for development technical solutions, technologies, standards and protocols interaction of SATCOM, EOSS and GNSS with ground infrastructure and with consumers.
• Key words
  • interoperability, space system, spacecraft, space complex, satellite communication system, the Earth observation satellites system, global navigation satellite system
• Reference
  • Makarenko S. I., Karutin A. I. Prospects and problematic issues of ensuring the interoperability of integrated space systems. Systems of Control, Communication and Security, 2021, no. 4, pp. 228-247. DOI: 10.24412/2410-9916-2021-4-228-247 (in Russian).

• M.A. Samoylichenko
  Modal filters for protection against ultrashort pulses: a study of the possibilities of effective use in double-sided printed circuit boards
• Abstract
  • The relevance of the work: The development of modern radioelectronic equipment (REE) is steadily moving to continuous growth of speed, autonomy and compactness. The designers are constantly searching for new signal transmission technologies and REE design methods. However, expanded operating frequency range, reduced supply voltage levels, and increased mounting density worsen the electromagnetic environment; elements of REE are becoming more vulnerable to electromagnetic interference. A dangerous type of such noise is an ultra-short pulse (USP), which is a powerful conducted interference of short duration. There is a large selection of protective devices but their specifications often limit their applicability. Therefore, it is relevant to improve their characteristics by simplifying their design and decreasing their manufacturing costs. A much simpler, in circuitry design and fabrication, is a device protecting from USPs, which is called a modal filter (MF). The significant advantages of MFs are their low weight, high reliability, radiation resistance, and high speed of operation. In addition, MFs can be integrated into printed circuit boards (PCBs), particularly, a double-sided one. One of the known options is the MF on a double-sided PCB with edge and broadside coupled conductors. However, because of the large number of passive conductors, it may be difficult to integrate such an MF into the PCB. Therefore, the purpose of the work was to investigate the effect of removing one and two passive conductors in an MF on a double-sided printed circuit board with edge and broadside coupled conductors. Result: It is shown that it is possible to decompose a USP in the MF realized on a double-sided PCB with edge and broadside coupled conductors when one and two passive conductors were removed. The attenuation of the signal was found to be the same for the modal filter with the conductors and without them. Methods used: The simulation was performed using the quasistatic analysis. Practical relevance consists in the possibility to provide a simple and low-cost protection against USPs in widely used double-sided printed circuit boards.
• Key words
  • modal filter, ultra-short pulse, printed circuit board, conductor influence
• Reference
  • Samoylichenko М. А. Modal filters for protection against ultrashort pulses: a study of the possibilities of effective use in double-sided printed circuit boards. Systems of Control, Communication and Security, 2021, no. 4, pp. 58-71. DOI: 10.24412/2410-9916-2021-4-58-71 (in Russian).

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• O. P. Kurkova
  MPPT algorithm frequency control as a tool for improving the energy efficiency of the process of contactless magnetic resonance charging of electric vehicles
• Abstract
  • Problem statement and specific task: Contactless magnetic resonance charging is currently recognized as one of the promising technologies for charging electric vehicles. However, when introducing contactless chargers, two main problems arise and must be solved: ensuring the compatibility of devices of various developers and manufacturers (since the сontactless magnetic resonance charging consists of two components – a stationary «translator» and an on-board «receiver») and ensuring energy efficiency. Based on the physical principle that is the basis of the contactless chargers, the maximum level of transmitted power can be achieved when the system as a whole is in a state of global resonance. The aim of the research was to develop an  algorithm for controlling the frequency characteristics of the contactless chargers, which allows for pairing a "translator" with an on-board "receiver" (including those that differ in type and class) automatically determine the value of the global resonant frequency for the actual pairing, corresponding to the maximum power that can be transmitted to the onboard load when charging the vehicle. Methods and technologies used: to solve the problem, when creating the algorithm, the method of "maximum power point tracking" (MPPT) is used; studies to identify the nature of the dependencies of the output power, output voltage and input current on frequency, as well as checking the efficiency of the algorithm were carried out on the basis of the method of equivalent electrical modeling of physical processes with the construction of models of processes occurring during the operation of the contactless chargers in the form of equivalent electrical circuits using the MATLAB/Simulink software package.  To generate numerical initial data for solving the main problem, the method of preliminary computational finite element modeling of electromagnetic processes and variants of resonant compensation topologies using the COMSOL software package is applied. Novelty of the result: the main novelty of the research result is the MPPT-algorithm for controlling the frequency characteristics of the contactless chargers, created on the basis of an equivalent electrical model of a system with a closed loop and feedback, which allows automatically determining the value of the global resonant frequency corresponding to the maximum output power when the "translator" is paired with the "receiver". Practical significance: the developed MPPT-algorithm can be used by the developers of the contactless chargers as an integral part of the algorithm of the charge process control controller as a tool for improving energy efficiency and ensuring compatibility of "translators" and "receivers" of various manufacturers.
• Key words
  • electric transport, contactless charger, magnetic resonance induction, compatibility, energy efficiency, resonance, equivalent model, frequency control algorithm, maximum power point tracking method
• Reference
  • Kurkova O. P. MPPT algorithm frequency control as a tool for improving the energy efficiency of the process of contactless magnetic resonance charging of electric vehicles. Systems of Control, Communication and Security, 2021, no. 4, pp. 99-124. DOI: 10.24412/2410-9916-2021-4-99-124 (in Russian).

• V. I. Levin
  Andrei D. Sakharov: a great scientist, public and political figure. Dedicated to the memory of the 100th anniversary of his birth
• Abstract
  • Relevance. In May 2021, the 100th anniversary of the birth of the great Soviet scientist and socio-political figure Andrei Dmitrievich Sakharov was celebrated. In this regard, it is very important to understand what he has done for science and to assess the impact of what he has done on science and society. The purpose of the article is to form an understanding of the fundamental processes of evolutionary and revolutionary approaches to the formation of new scientific knowledge, the laws of the development of science, the importance of a scientist's participation in public activities, using the example of the results of A.D. Sakharov's versatile activities. Result. To achieve the purpose of the article, the domestic literature on the history of science, the works of A. D. Sakharov himself, the memoirs of his colleagues are used. The article describes the meaning of the scientific results of A.D. Sakharov and his socio-political activities, the possibility of their use in practice. His biography has been recreated. The memoirs of his colleagues and acquaintances are given. His features as a scientist, a person, a public figure are described. Novelty and theoretical significance. The article recreates the creative and social activities of the famous scientist and socio-political figure. Its results and achievements are described. The work will be useful for young scientists studying the methodology of scientific research, as well as for specialists working on complex scientific and technical problems, as an example of their successful resolution.
• Key words
  • A.D. Sakharov, nuclear physics, hydrogen bomb, human rights
• Reference
  • Levin V. I. Andrei D. Sakharov: a great scientist, public and political figure. Dedicated to the memory of the 100th anniversary of his birth. Systems of Control, Communication and Security, 2021, no. 4, pp. 1-9. DOI: 10.24412/2410-9916-2021-4-1-9 (in Russian).