METHOD OF DOPPLER FILTRATION OF IONOSPHERE SIGNALS Russian patent published in 2014 - IPC G01R23/16 

FIELD: measurement equipment.

SUBSTANCE: method includes reception of an ionosphere signal with the help of a receiver, amplification and conversion by frequency, conversion of an analogue signal at the outlet of the receiver into digital form with the help of an analogue-digital converter. At the same time they reduce intermediate frequency of a signal to zero value with the help of Fourier transform. Elements of the correlation matrix $$A_{m,p}=\overline{{\widehat{Y}}_{n+m-1}{\widehat{Y}}_{n+p-1}^{\ast }}$$ are formed (line above means summation by index n), as well as elements of the right column $${\widehat{b}}_p=\overline{{\widehat{Y}}_{n+p-1}{e}^{-i\omega t_n}}$$ of the vector equation $$\widehat{A}\overline{c}=\overline{b}.$$ Elements $${\widehat{c}}_m$$ of vector of uncertain coefficients $$\overline{c}$$ are determined, by solving the vector equation $$\widehat{A}\overline{c}=\overline{b}$$ in a computer. Frequency dependence is formed for the probability functional $$\Delta \left(\omega \right)=\frac{1}{1-{\displaystyle \sum _{m=1}^M{\widehat{c}}_m{\widehat{Y}}_{n+m-1}^{\ast }}},$$ sorting frequencies with the specified pitch in the specified range of frequencies. Frequencies of Doppler components are assessed in the ionosphere signal, as well as their validity by maxima of frequency dependence of the probability functional Δ(ω). Elements of the matrix $$\widehat{A}{1}_{m,p}=e^{\overline{i({\omega }_m-{\omega }_p)t_n}}$$ and the right column $$\widehat{b}{1}_m=\overline{{\widehat{Y}}_n{e}^{-i{\omega }_m{t}_n}}$$ of the vector equation $$\widehat{A}1\overline{U}=\overline{b}1$$ are formed. Complex amplitudes of Doppler components of the ionosphere signal $${\widehat{U}}_1÷{\widehat{U}}_M$$ are assessed, solving the vector equation $$\widehat{A}1\overline{U}=\overline{b}1$$ in the computer.

EFFECT: increased accuracy and validity of assessments of Doppler spectrum of multi-beam ionosphere signals, and expansion of possibilities of spectral analysis in area of small intervals of signals processing, where Rayleigh criterion is not met.

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