METHOD OF DIGITAL DEMODULATION OF PHASE FIBER-OPTIC SENSOR SIGNALS

摘要

FIELD: measurement.;SUBSTANCE: invention relates to the field of measurement of physical quantities using phase fiber-optic sensors for measuring mechanical and acoustic vibrations. Method for demodulating a phase fiber-optic sensor signal includes auxiliary modulation of the phase difference of the above sensor with a harmonic signal, conversion of a periodic signal received from a photodetector installed at the output of the above sensor into a sequence of digital samples. Next, make the formation of sets of samples, the calculation of the desired phase difference, increase the frequency of sampling to a value four times the frequency of the auxiliary harmonic modulation of the phase difference, and use to calculate the value of the desired phase difference a set of five consecutive samples measured during one modulation period, the first sample is measured at the beginning, and the fifth one at the end of each auxiliary modulation period, after which the value of the desired phase difference is calculated for each set of samples.;EFFECT: technical result is improving the accuracy of digital demodulation of signals of phase fiber-optic sensors when the value of the desired phase difference in the sampling interval used in each calculation cycle varies.;1 cl, 7 dwg, 1 tbl