METHOD TO DETERMINE PLACE OF OPTICAL FIBRE DAMAGE Russian patent published in 2014 - IPC G01M11/02 G01N21/88 

FIELD: measurement equipment.

SUBSTANCE: control and current polarisation characteristics of backscattering of optical fibre are measured. When measuring the current characteristic with the help of a polarisation controller they vary the condition of polarisation of optical radiation at the inlet of optic fibre, and coefficients of correlation of reference and current polarisation characteristics are calculated along the length of optic fibre. According to the produced characteristics, a section with damage is defined as the section, in which the correlation coefficient varies by the value exceeding the threshold value. The distance to the place of damage is determined as the distance to the point of crossing of characteristics of variation of correlation coefficient of reference and current polarisation characteristics of backscattering along the length of optic fibre under maximum value of correlation coefficient at near and far end, accordingly.

EFFECT: elimination of errors introduced by variation of polarisation condition under repeated connections of an optical reflectometer and reduced error in determination of distance to a place of fibre damage.

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