METHOD OF DETERMINING DISTANCE TO OBJECT Russian patent published in 2017 - IPC G01S17/08 

FIELD: measuring equipment.

SUBSTANCE: object is illuminated by laser radiation, the radiation reflected from the object interfering in the laser is converted into an electrical autodyne signal. Laser radiation with frequency equalling to ω₀ is modulated according to the harmonic law with frequency ν by modulating the laser power supply current. The wavelength of the radiation is changed by an amount of Δλ; the amplitude component of the autodyne signal is filtered at a frequencyν. The signal is decomposed into a spectral series, the amplitude of the 2n-th (C_2n) and 2n+2-th (C_2n+2) harmonics of the spectrum or 2n+1-th (C_2n+1) and 2n+3-th (C_2n+3) harmonics of the spectrum of the autodyne signal. The value of the argument of the Bessel function of the first kind σ Is calculated with respect to C_2n/C_2n+1(σ) or C_2n+1/C_2n+3(σ), respectively. The distance to the object L is found by the formula .

EFFECT: significant increase in the accuracy of measurement of the amplitude of the nanovibrations of the object.

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