CPC G01H 9/004 (2013.01) [G01D 5/35354 (2013.01); G01D 5/35361 (2013.01); G01V 1/226 (2013.01)] | 15 Claims |
1. A method for remotely sensing vibration, comprising:
transmitting, by a light pulse generator apparatus, a plurality of optical pulses through an optical fiber at a predetermined frequency, the transmitting comprising:
generating, by a light source of the light pulse generator apparatus, continuous-wave light;
converting, by a first optical modulator of the light pulse generator apparatus, the continuous-wave light into the plurality of optical pulses having the predetermined frequency;
amplifying, by an optical amplifier of the light pulse generator apparatus, the plurality of optical pulses;
directing the optical pulses to a first port of an optical circulator of the light pulse generator apparatus;
directing, by the optical circulator, the optical pulses to a second port of the optical circulator in optical communication with the optical fiber;
tuning, by a first polarization controller of the light pulse generator apparatus, the continuous-wave light;
tuning, by a second polarization controller of the light pulse generator apparatus, the plurality of optical pulses; and
enhancing, by a second optical modulator of the light pulse generator apparatus, configured to operate substantially in synchronicity with the first optical modulator, an extinction ratio of the optical pulses;
detecting, by an optical receiver apparatus, a plurality of backscattered Rayleigh traces from the optical fiber based on a vibration of the optical fiber at a vibration frequency at a location along the optical fiber;
determining, by the optical receiver apparatus, a normalized differential trace based on the plurality of backscattered Rayleigh traces;
determining, by the optical receiver apparatus, based on the normalized differential trace, the location in the optical fiber of the vibration; and
determining, by the optical receiver apparatus, based on the plurality of backscattered Rayleigh traces, the vibration frequency.
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