Характеристики обнаружения когерентной системы селекции движущихся целей при рассогласовании параметров квадратурных каналов.

Abstract

ntroduction. Operation of adaptive system of moving targets selection is considered, which is represented by single intermittent subtractor with coherent accumulator, which is tuned in frequency. System of moving targets selection is made in the form of two quadrature channels, in which high-frequency passive interference and signal from moving object are converted to video frequency with subsequent rejection, accumulation and comparison with threshold level. Setting the task. Investigation of the effect of the inevitable in practice amplitude and phase misalignments of quadrature channel parameters on the detection characteristics of the adaptive selection system of moving targets. Method. Method of complex variable is used, in which passive interference and signal from moving object at input and output of adaptive selection system of moving targets are presented in the form of pair of real components shifted in phase by ninety degrees. Results. Models of passive interference and signal from moving object are presented taking into account possible in practice amplitude and phase mismatches of quadrature channels parameters. The structure of the processing device is shown, which includes a series-connected generator of quadrature components of passive interference and a signal from a moving object, an adaptive cutting filter in the form of a single intermittent subtraction circuit with a frequency-tuned rejection zone, an adaptive coherent accumulator and a threshold device. Expressions are obtained for complex correlation functions of passive interference and signal from moving object at output of coherent accumulator taking into account inevitable amplitude and phase mismatches of quadrature channels parameters. Dependencies of probability of correct detection of signal from moving object against the background of passive interference from value of deviation of transmission coefficients of quadrature channels and phase mismatch of reference voltages for different values of average frequency of spectral density of passive interference are calculated and constructed. Conclusion. Significant dependence of probability of correct detection of signal from moving object on average frequency of spectral density of passive interference, as well as amplitude and phase mismatches of quadrature channels parameters is shown.