METHOD OF MEASURING ABSOLUTE DISTANCE Russian patent published in 2020 - IPC G01B11/14 G01S17/32 

FIELD: measurement.

SUBSTANCE: invention can be widely used in precision machine building and electronic engineering. Increased measurement accuracy, in particular, enables to control the process of development of precision devices in computer equipment, in micro- and nanoelectronics. Disclosed method of measuring absolute distance includes direction of radiation of laser diode on measured object, modulation of current supply of laser by frequency ν, conversion of the radiation reflected from the object into an autodyne signal, registration of the autodyne signal, decomposition of the autodyne signal into the Fourier spectrum. In the Fourier spectrum of the autodyne signal, measuring the harmonic frequency with the maximum amplitude, approximating the amplitude amplitude of spectral components greater than the maximum amplitude, frequency corresponding to half value from maximum amplitude is measured. Distance is calculated using ratio

,

where ν_n is frequency corresponding to half value from maximum amplitude, ν is modulation frequency of laser diode supply current, λ is laser wavelength, Δλ - laser wavelength deviation, π is Pi number.

EFFECT: possibility to measure absolute distance without contact with micron accuracy.

1 cl, 5 dwg