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Ukrainian navigational aids network has a long history of deployment and development. Currently, navigational aids network includes ground equipment of Distance Measuring Equipment (DME), Very high-frequency Omni-directional Ranging (VOR), and Non-Directional Beacons (NDB). In our research, we would like to provide an overall study of navigational aids network configuration to specify the impact of particular ground station on the service provided. Common models of navigational aids are considered to estimate navigational aids availability and efficient pair forming in case of positioning by DME/DME and VOR/VOR. An area of correspondence to RNAV requirements is used as a criterion to estimate the impact of each navigational aid on overall network performance. Also, the navigational aids network is represented in the form of a weighted graph to estimate characteristics of centrality and betweenness for ranging network nodes. Configuration of Ukrainian navigational aids network is studied as an example. Obtained results are useful for a better understanding of navigational aids network configuration.

In this paper, some cybersecurity vulnerabilities of modern UASs were considered. Vulnerabilities of communication, navigation, control, and surveillance equipment of modern UASs were analyzed. The cyber threats analysis and assessment algorithm were presented. The proposed algorithm is focusing on possible intruders’ portrait that can be important when qualitative risk assessment. The approach to assess the UASs cyber hazards connected with considered vulnerabilities and threats was made. It was stressed that the particular assessment highly depends on the properly defined mission, potential intruders, and even social and political situation. A short overview of the recommendations to mitigate risk connected with cyber hazards was done.

The paper deals with the problem of mathematical models building for diagnostic variables of radio electronic systems in the case of data heteroskedasticity. The heteroskedasticity is associated with event when clusters from single sample are characterized by different values of variance. In operation theory heteroskedasticity occurs in case of equipment technical condition deterioration. The paper describes the method for taking into account heteroskedasticity, which includes the following steps: building and choosing the best regression model; calculation of heteroskedasticity index based on minimization of weighted sum of residuals squares; determining correction coefficients of heteroskedasticity and obtaining the final regression equation. The proposed methods can be used during utilization of condition-based maintenance with diagnostic variables monitoring.

The paper deals with the problem of synthesis and analysis of sequential procedure for identifying the deterioration of the technical condition of radio equipment. Radio electronic equipment plays a leading role in ensuring the safety and regularity of flights. The operation system includes equipment, technological processes, personnel, regulatory documentation, resources, and determines the reliability of the equipment. Decision-making in operation systems is based on the results of statistical data processing. The initial data for processing are reliability indicators and determining parameters of radio equipment. In general case, the technical condition of the equipment during operation may deteriorate. Detection of changes in the technical condition can be considered as a task of analyzing the changepoint. In this article, the synthesis of a sequential detection procedure with a previously unknown sample size was performed. During the synthesis, analytical equations for decision thresholds were found. The analysis of the sequential procedure was performed analytically and using statistical simulation. Analytical equations were found for the mathematical expectation of the duration of decision-making and for the operational characteristic. The research results can be used during the design and modernization of operation systems of radio equipment in terms of synthesis of operational data processing procedures

This chapter presents the questions of aviation radioelectronic equipment operation. Operation is the main stage in the life cycle of equipment. This stage is the longest in time and very significant in terms of the costs for equipment reliability providing. Control influences are realized in operation system to provide the efficient functioning of the equipment. The operation system is complex in structure intelligence system and is the object of design and modernization. The chapter deals with the structure of the operation system and its elements interconnection and discusses the models of diagnostic variables, reliability parameters for the case of changepoint presence. An important issue during design and improvement of operation systems is the selection, evaluation, and support of the efficiency indicator. This chapter concentrates on the efficiency indicator substantiation taking into account the effectiveness and operational resources costs. Three data processing strategies analysis allowed choosing the most rational option from maximum efficiency point of view.

The reliability of radio equipment depends on its operation system. The operation system includes: radio equipment, processes, personnel, documentation, operational resources, data processing algorithms, etc. During operation the technical condition of radio equipment can deteriorate. This paper concentrates on the problem of synthesis and analysis of method for deterioration detection during radio equipment operation. The synthesis of the detection algorithm is based on Neyman-Pearson criterion with sample size accumulation. The decision thresholds were calculated according to Bellman’s approach. The problem of analysis was solved by statistical modelling based on the Monte-Carlo method.

This paper concentrates on the rationale for statistical data processing in ground-based radio and electronic equipment operation system. In this regard, a comparative analysis of the two maintenance strategies was performed. The first strategy is based on planned maintenance and repair procedures in case of equipment failure. In the second strategy, decision on the implementation of preventive actions based on the results of statistical data processing on diagnostic variable trends changes. An indicator of the efficiency of each strategy is the mathematical expectation of operation costs. A probabilistic-event model was used for formula determination. The limiting ratios for the efficiency improvement indicator were found. The requirements for the average cost of statistical data processing were defined on basis of limiting ratios.

In this chapter, the authors present the questions of aviation radioelectronic equipment operation. The structure of operation system is considered based on processes approach with adaptable control principles usage. Operation system contains processes of diagnostics and health monitoring. The authors consider the direct problem of efficiency estimation for diagnostics process, and main attention is paid to probability density function calculation for diagnostics duration. Simulation results were used for adequacy testing of these calculations. The authors also take into account the possibility of first and second kind errors presence. The inverse problem for diagnostics is defined and solved for mathematical expectation of repair time. In general case, the inverse problem can be solved for seven options of optimization.

Serviceable functioning of radioelectronic equipment is determined by reliability parameters and achieved by the quality and efficiency of its operation system. The paper concentrates on problem solving of analysis and synthesis of algorithms for changepoint detection in the trend of changing the mean time between failures of radio equipment. In order to solve this problem, before and after deterioration of equipment technical condition an exponential models with different failure rates are used. The synthesis of the detection procedure is based on Neyman-Pearson criterion with a fixed sample size. The problem of analysis was solved analytically and by modelling based on the Monte-Carlo method. The simulation confirmed the correctness of theoretical calculations.

Як відомо, сонячне випромінювання, потрапляючи на фотоелемент, перетворюється не тільки в електричну, але й у теплову енергію, нагріваючи його поверхню. Тільки 6–20 % сонячного випромінювання використовується для отримання електроенергії. Інша частина енергії в основному витрачається на нагрівання фотоелемента, що значно знижує ефективність його роботи. Коефіцієнт корисної дії перетворення сонячної енергії зменшується у разі збільшення температури. Цю статтю присвячено зменшенню впливу нагріву фотоелемента на ефективність перетворення ним сонячної енергії шляхом встановлення його на додаткову охолоджуючу поверхню, яка грає роль радіатора. Дані щодо величини сонячного випромінювання, яке падає на одиницю площі фотоелемента, температури навколишнього середовища та швидкості вітру взяті для м. Сімферополя. У роботі виконанийрозрахунок площі додаткової охолоджуючої поверхні. Встановлено, що для повної компенсації нагріву фотоелемента площа цієї поверхні повинна бути в 2 – 2,2 рази більша за площу фотоелемента. У результаті моделювання були отримані дані не щодо площі додаткової поверхні А', а щодо відношення цієї площі до площі фотоелемента А'/А. Ці відомості, на думку авторів, є більш наочними, універсальними та зручними для подальшого аналізу.

Procedure of statistical data processing about times between failures in operation system of radio engineering devices was considered. That procedure consists of normal probability plot construction with two variants of its approximation and choosing the more effective variant with the help of statistical data linearity testing.

The article deals with the problem of substantiation of necessity of statistical data processing procedures during UAV operation. These procedures are used in case of realization of preventive maintenance at the use of operation strategy according to the condition with control of diagnostic variables. The quantitative estimation of data processing veracity was determined by simulation of availability coefficient estimation algorithm.

The paper deals with the problem of synthesis and analysis for procedures of reliability parameters estimation in case of radioelectronic devices technical state deterioration. The synthesis problem was solved on the basis of the maximum likelihood method. The analysis problem was solved using analytical calculations and based on statistical simulation.