86The principle of operation of IKSO, which is to record signals with diversity of pyrocatechol into the appropriate memory registers and output detection of the differential signal envelope. Subsequently, from the memory registers portions of a recording signal posted pyrocatechol are selected which are later processed to determine the temporal provisions of minimum minimore and maximum maximore. The direction of movement of the object abeam is determined by the delay or advance of the extrema of the signals of one sensor relative to another within a given temporal "slot".It is shown that aggregation should be the following -the tool with a maximum radius of the zone of sensitivity should be active and the basic, but if there is a more reliable piece of information about the detected object which can implement a more refined classification of the object (for example, a group of people, wheeled vehicles-tracked vehicles, etc.). The conclusion is made about the advantages of differential option to include spaced sensors.The results can be used in the development of infrared wavelengths passive detection in the conceptual design phase.
При разработке радиолокационных систем повышенной информативности целесообразно использовать поляризационно-модулированные сигналы. Это обеспечивает максимальное количество информации о поляризационных характеристиках радиолокационных объектов (РЛО); возможность эффективной поляризационной селекции объектов на фоне мешающих отражений, поглощающих покрытий и организованных помех; использование полной эффективной поверхности объекта, что особенно важно при обнаружении РЛО; возможность извлечения информации об их форме для распознавания, повышения помехоустойчивости радиолокационных станций; поляризационное усреднение угловых шумов протяженных РЛО; снижение стоимости системы (по сравнению с дорогостоящими системами построения портрета цели с помощью сверхкоротких импульсов либо многочастотных сигналов).Цель работы -определение связи информативности параметров поляризационно-модулированных сигналов с достаточным количеством информации на основе обработки экспериментальных данных. Предложена методика оценки информативности поляризационных характеристик данных сигналов, отраженных от РЛО. На основе обработки экспериментальных данных выяснено, что уже двумерные поляризационные признаки поставляют количество информации, превышающее достаточное. Наименее информативными являются структурные поляризационные признаки, связанные с эффективной поверхностью рассеяния цели. Однако некоторые из структурных признаков могут быть использованы для классификации РЛО, например коэффициент корреляции между ортогональнополяризованными компонентами сигнала.Достаточно высокую степень информативности имеет совокупность признаков: коэффициент деполяризации, коэффициент анизотропии и коэффициент асимметрии. Вероятность распознавания класса РЛО может быть существенно увеличена при возможности реализации накопления поляризационной информации.Ключевые слова: поляризационные характеристики; признаки распознавания; информативность параметров.Для цитирования: Акиншин Н.С., Румянцев В.Л., Акиншин О.Н. Экспериментальная оценка информативности поляризационно-модулированных сигналов // Изв. вузов. Электроника.
It is known that one of the most complicated problem in a radar direction finding is a problem of an effective detection and recognition of objects, especially fixed ones [1,3]. In the paper it is shown that one of the promising approaches for solution of the problem lies in use of polarization parameters of radar-tracking signals.The results of analysis of radiation scattering by objects confirm, that the polarisation characteristics can bear an extensive information both about object parameters and about its operation. It is established, that the polarization characteristics of objects at the specific frequency of exploration and fixed direction of observation can be given by five material parameters (Hujnen's descriptors) [2,4-61:"Noticability or size of an object" (m) -maximum amplitude of a polarized signal is a measure of a size or effective scattering surface (ESS) of object; "Object orientation angle" (cp) -is defined as an angle between a large axe of an ellipse and axe of an object's symmetry (measure of orientation concerning a line-of-sight); " Angle of an ellipticity " ( 7 ) -(measure of object's symmetry to right-hand and left-hand circular polarisation); "Slide angle" (v), describing a multiplicity of signal from object reflections;Polarization angle, characteristic angle " (y), (measure the ability of object to polarize an incident non-polarized radiation).When studying different options of radar-tracking systems construction the specified parameters contain full information about polarization structure of a signal. These parameters are also invariant to object's velocity, power of the reflected signals and polarizing base of the radar-tracking system.In the paper the expressions for calculation of five descriptors are derived and the theoretical investigation on evaluation of possibility of small-size ground objects detection based on polarization properties using polarization parameters vector was carried out.Basic outcomes of experimental research of descriptors for objects in millimeter range are given below which rather well confirm theoretical conclusions about the possibility of such objects detection using polarization parameters vector Fig. 1-3 shows the variants of experimental histograms of m,v and y descriptors approximation for wheel and caterpillar-based (tankemode) vehicles (fixed) and underlying earth surface (equal district with a grass and rare bush of less than Im height) are submitted. The following designations are used: number 1-curve for an light armoured drive truck (EADT), number 2 -for ZIL-131 truck and number 3 -for a underlying earth surface.The experiments shown that the probability of correct detection of objects is 0,87 and 0,81 correspondingly.On the fig. 4 the two-dimensional image for the same objects and similar conditions is given in the space of parameters z and m. Here z is magnitude of a ratio component cross-sectional and basic polarizations expressed in decibels. The A numeral designates magnitude z for a underlying earth surface, 0-the same for ZIL-131 and...
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