RADIO-WAVE METHOD OF MEASURING GROUND SPEED AND DRIFT ANGLE OF AIRCRAFT Russian patent published in 2017 - IPC G01S13/58 

FIELD: measuring equipment.

SUBSTANCE: in the method of measuring the ground speed and the drift angle of the aircraft, consisting in radio waves irradiation of the underlying surface with two antenna systems, each of which is oriented at an angle θ on each side from its axis in the horizontal plane and at β₀ angle in the vertical plane, receiving reflected waves, mixing with part of the radiation wave mode and extraction of the two signals of the difference frequency, the frequency of the radio waves is modulated according to the symmetric linear law, for each of the two signals of the difference frequency, pairs of spectra are calculated on the frequency-increasing and frequency-decreasing modulation sections, S₁₁, S₁₂ and S₂₁, S₂₂ respectively, then the frequency shifts corresponding to the maxima of the cross-correlation function for the first and second pairs of spectra - ƒ_D1 and ƒ_D2 - are determined, the frequency shift dƒ of maximum of the cross-correlation function between spectra S₁₁ and S₁₂ amount, displaced by f_D1 upwards and downwards according to the frequency scale, and calculated after a time interval dt, ground speed W and drift angle ϕ are determined according to the ƒ_D1, ƒ_D2 and dƒ values.

EFFECT: increased accuracy of measurements.

6 dwg