METHOD AND DEVICE FOR PRECISION LASER-INTERFERENCE MEASUREMENT OF DISTANCES AND DISPLACEMENTS Russian patent published in 2020 - IPC G01B9/02 G01S17/36 

FIELD: measurement.

SUBSTANCE: invention relates to measurement equipment and method of measuring distance to object. Method comprises steps of emitting a light beam using a multimode laser, reflecting a light beam from a mirror attached to the object, forming an interference pattern between the light beam and the reflected light beam, generating an interference signal corresponding to the intensity of the interference pattern. Coarse distance to the object is determined based on the frequency of intermode beats of the light beam and the visibility of the interference pattern. Besides, performing electro-optical modulation of light beam by reference signal, determining phase difference between interference signal and reference signal, measuring fractional portion of interference band between light beam and the reflected light beam based on the found phase difference and determining the accurate distance to the object based on the measured fractional portion of the interference band between the light beam and the reflected light beam.

EFFECT: technical result is increase in the measurements accuracy.

6 cl, 6 dwg