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Information × Registration Number 0218U000588, 0115U000224 , R & D reports Title The theoretical foundations development and methods for static and dynamic spectral estimation of signals in radar popup.stage_title Head Lubchik Vitaliy Romanovich, Доктор технічних наук Registration Date 13-02-2018 Organization Khmelnytskiy National University popup.description2 Object of research: Theory of multifrequency phase radar distance measurement. Subject of research: Processes of multifrequency phase radar determination of range and radial velocity of moving and immobile targets. Objective: development of the theory of multifrequency phase-farmeter, development and research of methods of radar measurement of range and radial velocity of targets, taking into account frequency characteristics of systems, trajectories of radio wave propagation. Research methods. Methods of the theory of radio engineering systems, differential calculus, theory of complex numbers, linear algebra, theory of measurements, theory of errors, probability theory and mathematical statistics, methods of numerical solution of equations and systems of linear equations were used to solve problems posed in the dissertation. Experimental studies were conducted using experimental models and measuring instruments as well as physical and mathematical simulation methods through numerical analysis and computer simulation using the application package Maple15, MatLab2013 and computer programs written in programming languages C ++ and Pascal. Theoretical results. The theoretical foundations of multi-frequency phase measurements of the range of objects and their parameters have been further developed. The basis for further development of the theory is the interdependence of the amplitude and phase shift of the harmonic probing signals at different frequencies, which manifests itself in the growth and decrease of the amplitude of the total signal at the point of reception at acquisition, which made it possible to obtain analytical dependencies that establish the relationship between signals repelled from each object and total reflected signal in trigonometric and exponential forms. The analytical multifrequency phase methods of measuring the range and parameters of objects, which consist in solving the system of nonlinear equations, are developed. which describes the dependencies of the total reflection of the harmonic signal and the signals reflected from each object at frequencies 1: 2: 3: ...: 2N. To record the system of equations, N is probed by 2N signals. The result of the solution of the system of equations is the value of the parameters of the vectors of harmonic signals, reflected from each object. The dependences of error and resolution of multifrequency phase methods from the error of determining the grid of probing frequencies, the frequency step, the error of the determination of phase shifts, and the amplitudes of the total reflection signals are investigated. A mathematical modeling of the range measurement was conducted, which showed that the error of measuring the range and the resolution with decreasing error of frequency setting and expanding the step of changing the frequency of probing signals decreases with exponential dependence. With a decrease in the measurement error of phase shift and the amplitude of total probe signals, the measurement error of the range falls linearly. The analytical dependencies of finding the errors of measuring the range by different methods are obtained, depending on the errors of determining the parameters of the total harmonic signals. In the application of analytical phase methods for measuring the range, the number of conditionality of the matrix of the system of equations, which describes the relationships between total sounding signals and signals shifted from each object, has a significant influence on the accuracy of the distance determination. Practical results. 1. Mathematical models and algorithms of mathematical modeling of the multifrequency phase method are developed, taking into account instability of frequency of probing signals, influence of noise on the results of sounding and measuring of phase shifts and amplitudes of aggregate signals. As a result of mathematical modeling in the MatLab environment, the adequacy of the analytical expressions of the multi-frequency phase method for measuring the range of sub-surface objects is shown. 2. Structural schemes and algorithms of sub-surface radar sounding systems are developed. The main blocks of the circuit are the synthesizer of probing frequencies, blocks of measurement of amplitude and phase shift of the total probing signals and the unit of calculation. 4. The structural and principle schemes of the voltmeter of the mean-square values of increased accuracy are developed. A laboratory model has been manufactured and its metrological characteristics have been investigated. 5. Laboratory models of devices for finding objects, determining the range and their coefficients of reflection by the multifrequency phase method are developed and manufactured. Proven performance of the method with the help of developed and manufactured models by measuring the heterogeneities of cable lines. 6. Structural schemes of radar surveillance systems have been developed, which in their composition have the following compulsory blocks: frequency grid synthesizer or signal synthesizer with a rectangular by-pass spectrum; a receiving and transmitting unit, which can consist of one transmitting and one or three receiving antennas; a block of measurement of phase shifts and amplitudes of common signals or a block of discrete Fourier transform; computing device and indicator. 7. The algorithm of operation of multi-frequency phase systems for determination of range and radial velocity of air targets, which allows to automatically generate a grid of probing signals in an automatic mode, conduct sounding of targets, measure phase shifts and amplitudes of total reflection signals, calculate the range, coefficients of reflection of targets, radial velocities of moving goals. Efficiency of implementation. The application of the developed methods allows to detect and observe sub-surface objects, which are mines, underground tunnels, communications, etc. For multi-frequency phase methods, there are modifications that allow for taking into account the electrophysical properties of different subsurface environments, which, in turn, increases the accuracy and resolution in depth. The results of scientific development can be used for the construction of radar systems and complexes of various purposes. Scope of use. Theoretical positions and methods of radar measurements can be used for the development of fundamentally new systems of ranging and measurement of radial velocity of targets in civilian and military areas. This is especially true in the development of radar systems, which must distinguish between targets at short distances from each other on a single line. The feature of the method is the possibility of using continuous probing signals, which will allow the development of radar systems with simultaneous high-precision measurements of both range and radial velocity of objectives. It is also possible to use probe signals with a rectangular by-pass spectrum and a minimum peak factor, which are deterministic noise signals, which can provide secrecy of sounding while preserving the advantages of active radar systems Product Description popup.authors Євтушок Володимир Павлович Карпова Леся Вікторівна Левчунець Денис Олександрович Любчик Віталій Романович Рибій Віктор Олександрович Сенчишина Юлія Володимирівна Стецюк Віктор Іванович Чесановський Іван Іванович Шинкарук Олег Миколайович popup.nrat_date 2020-04-02 Close