Оптимізація поляризаційно-доплерівської селекції малорозмірних об’єктів на тлі підстильної поверхні

Using the method of maximum likelihood, the optimal algorithm of polarization-Doppler selection of objects on the background of the underlying surface, hydrometeors, urban buildings from aerospace carriers of radio electronic equipment has been synthesized. To solve the problem polarimetric properties of the scattered electromagnetic radiation of natural environments and anthropogenic objects were analyzed.The functional-deterministic mathematical model of the useful signalis determined. When solving the optimization problem, the method of maximum likelihood functionality and likelihood functionality for correlated processes were used, which contains the inverse matrix of inverse correlation functions of the observation equation. The obtained signal processing algorithm includes operations of spectral resection of passive interference. Polarization compensation of passive interference is performed by a combination of interchannel subtraction of the reflected signals of different polarizations. The quasi-optimal features of the synthesized algorithm, which has an obvious physical value and is optimal in the absence of internal noise, are considered. Based on the obtained results, a block diagram of the polarization-Doppler noise compensator and selection of useful signals against the background of noise reflections from the earth's surface has been developed. The study of the physical characteristics of the elements of the polarization covariance matrix of interferences at a high level of correlation of reflections of passive interferences of different polarizations is conducted.Based on the obtained results, it is proposed to introduce indicators of efficiency of passive interference compensation and selection of useful signals. The results of the analysis of the obtained indicators depending on the coefficient of the ratio of variances of passive interference indicate the need to use the polarization differences between signals and interference for selecting objects against the background of the underlying surface. The results obtained can be used to create ground-based and aerospace-based radar systems for detecting moving objects and objects with pronounced polarization features.

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СИНТЕЗ ОПТИМАЛЬНОГО АЛГОРИТМУ ПОЛЯРИЗАЦІЙНОЇ СЕЛЕКЦІЇ КОРИСНИХ СИГНАЛІВ НА ФОНІ ПАСИВНИХ ЗАВАД В РАДАРІ З СИНТЕЗУВАННЯМ АПЕРТУРИ

Aerospace technic and technology ◽

10.32620/aktt.2020.4.14 ◽

2020 ◽

pp. 109-115

Author(s):

Валерій Костянтинович Волосюк ◽

Володимир Володимирович Павліков ◽

Семен Сергійович Жила ◽

Микола Вікторович Руженцев ◽

Володимир Віталійович Кошарський ◽

...

Keyword(s):

Maximum Likelihood ◽

Background Radiation ◽

Optimal Algorithm ◽

Underlying Surface ◽

Matched Filtering ◽

Antenna Aperture ◽

External Interference ◽

Useful Signal ◽

Passive Interference ◽

Selection Of

Using the method of maximum likelihood, the optimal algorithm of polarization selection of objects on the background of the underlying surface, hydrometeors, urban buildings from aerospace carriers of radio electronic equipment has been synthesized. To solve the problem polarimetric properties of the scattered electromagnetic radiation of different natural environments and anthropogenic objects were analyzed. Has been determined the functional-determined mathematical model of the useful signal, the structure and correlation characteristics of scattered background radiation and white noise inside the multichannel receiver. It is assumed that the wanted signals are measured with phase accuracy in a coherent receiver. When solving the optimization problem, the method of the maximum likelihood functional and the likelihood functional for correlated processes were used, contains the inverse matrix of inverse correlation functions of the observation equation. The obtained signal processing algorithm, in addition to the classical operations of accumulating the trajectory signal with the preservation of the phase structure and its matched filtering, provides for polarization and frequency selection in the line of decorrelation filters. In the case when the internal noise is very small in comparison with external interference and the correlation between the channels of vertical and horizontal polarization approaches unity, almost complete compensation of passive interference occurs. Further spectral rejection of the reflected signals is practically unnecessary and it is possible to restrict ourselves only to matched filtering of the useful signal. In the absence of background radiation correlation, the channels for receiving oscillations of different polarizations become independent and the main operation for the selection of useful signals is spectral rejection of passive interference and matched filtering of the useful signal. The developed algorithm can be implement in cognitive radars due to its adaptability to the parameters of background radiation in accordance with the change in the scattering covariance matrix of the underlying surface. Based on the results obtained, a block diagram of a multichannel polarization radar with synthesized antenna aperture has been developed.

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Дослідження якісних показників поляризаційної селекції об’єктів на фоні пасивних завад в поляризаційно-доплерівській радіолокаційній системі

Aerospace technic and technology ◽

10.32620/aktt.2021.6.07 ◽

2021 ◽

pp. 62-73

Author(s):

Валерій Костянтинович Волосюк ◽

Володимир Володимирович Павліков ◽

Семен Сергійович Жила ◽

Анатолій Владиславович Попов ◽

Володимир Віталійович Кошарський ◽

...

Keyword(s):

Optimal Algorithm ◽

Internal Noise ◽

Correlation Coefficients ◽

Information Value ◽

Residual Variance ◽

Optimal Processing ◽

Useful Signal ◽

Input Signals ◽

Passive Interference ◽

Selection Of

The optimal algorithm of polarization-Doppler selection of targets against the background of passive interference is considered. The polarimetric properties of scattered electromagnetic radiation of objects. The functionally-determined mathematical model of the useful signal, structure and correlation characteristics of the internal radiation of the receiver is determined. The algorithm of optimal processing, synthesized within the method of maximum likelihood, is considered for two limit cases. Algorithmic actions in the processing of passive interference and methods of their compensation are considered and investigated. Based on the obtained results, the expression for the algorithm of compensation of interferences reflected from the earth's surface is written. The obtained algorithm equalizes the variance of the input signals and compensates the residual variance with the help of weight coefficients. On the basis of the developed algorithm the scheme of the structurally simplified optimum compensator of passive disturbances is formed. Feature processing of useful signals in the compensation scheme is investigated. To ensure the adaptability of the generated algorithm, the coefficient of the variance ratio is based on the results coming from the variance meter. It is proposed to introduce quality indicators of polarization object selection on the background of the underlying surface, which combines indicators of efficiency of passive interference compensation and indicators of efficiency of useful signal-processing against the background of internal noise of receivers. The corresponding dependence of the indicators on the correlation coefficients of passive interference of different polarizations, as well as on the coefficients that separately characterize the level of difference in signal intensities and interference in the reception channels. The information value of each indicator of the efficiency of polarization signal selection from the ratio of the input variances, the correlation coefficient of passive interference and the ratio of the input signals is investigated.The obtained results are proposed to be used to improve the quality of polarization selection of objects in ground-based and aerospace-based radar systems.

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