Patent UA-104208-C2 (UA)
Title: Method for digital correlation radio direction finding
Inventor: TSYPORENKO VITALII VALENTYNOVYCH
IPC: G01S5/04
Filed: 2012-03-19
Abstract: A method for digital correlation radio direction finding relates to radio-electronics and can be used in radio-electronic facilities for different purposes, in particular in radio-navigation, radio location, radio astronomy, radio monitoring. Radio-wave radiation is received by two fixed, separated in space antennae with following preliminary selection, with coherent transformation of frequency within the boundaries of pass band and with amplification in two radio-channels tuned intended working frequency. Amplified radio-signals are converted to digital form with determination of complex frequency spectra of those. After that the shift of those by frequency from the band of intermediate frequency to the band of working frequency is performed through addition to the values of frequencies of spectral components of the value of frequency shift equal to difference between the set working frequency of adjustment of radio-channels and intermediate frequency. The inversion of shifted spectrum of signal of one of radio-channels is performed. Then the readings of same frequencies of direct and inverted shifted complex frequency spectra are multiplied, and the first spectra product is obtained. Then first transformation of the first product of spectra through multiplication of arguments of its spectral components by coefficients inversely proportional to the values of respective frequency readings is performed, and the first representation of the first transformed spectra product is obtained. Then the second representation of the transformed first product of spectra is formed through the first representation shift by frequency. Then inversion of one of representations of the transformed first spectra products is carried out, with multiplication of the readings with same frequencies of those, with formation of the second spectra product. Then the second spectra product is transformed through multiplication of the arguments of its complex spectral components by coefficients that are directly proportional to the values of respective frequency readings. Then integer part of extreme value of compensation parameter of one of radio-channels is determined as an argument of the sum of complex frequency readings of the transformed second spectra product. Then the second transformation of the first spectra product is performed through adding to the arguments of its complex spectral components of integer part of extreme value of compensation parameter of one of radio-channels with formation of total arguments and following multiplication by coefficients that are inversely proportional to the values of respective readings of frequency. After that extreme value of compensation parameter of one of radio-channels that corresponds to the maximum value of mutual correlation function is determined as an argument of the sum of complex frequency readings of the second transformation of the first spectra product. After that by the extreme value of the compensation parameters of one of radio-channels determined and with account of spatial arrangement of antennae a direction to the source of radio radiation is determined. The method makes it possible to increase accuracy of radar direction finding.