Abstract
We present a theoretical and experimental study in which we increased the sensitivity of a phase-sensitive optical time-domain reflectometer (phi-OTDR). This was achieved by constructing coils in the sensor cable, which increased the total amplitude of the impact on the fiber. We demonstrate this theoretically using the example of a phase-sensitive reflectometer model and practically in testing grounds with a buried nearby conventional sensor and a sensor with coils. The sensitivity increased 2.2 times. We detected 95% of events when using coils, versus 20% when using a straight cable. The suggested method does not require any modifications to the device.
Highlights
Several methods have been proposed to increase the acoustic sensitivity of fiber-optic systems (FOSs), such as the use of a special cable with improved acoustic sensitivity [24,25,26,27,28], several photoreceivers together with special data-processing algorithms [29,30], and a special optical fiber with weak fiber Bragg gratings recorded in a fiber with a known periodicity [31,32,33,34]
One possibility for increasing the SNR was investigated by using two probe pulses simultaneously [35,36,37,38], including with a certain polarization configuration [39,40]. We study another way to increase the acoustic sensitivity of a phasesensitive optical time-domain reflectometer
The paper considered how fiber coils in cable affected the acoustic sensitivity of a phi-OTDR
Summary
Distributed fiber-optic systems (FOSs) are used in a large number of areas for recording acoustic impacts: in seismometry, including for oil wells [1,2,3,4,5,6,7]; for monitoring activity near long objects, such as perimeters and pipelines [8,9,10]; and for monitoring railway tracks and transport [11,12] as well as structures, including engines, buildings, and composite airplanes. Several methods have been proposed to increase the acoustic sensitivity of FOSs, such as the use of a special cable with improved acoustic sensitivity [24,25,26,27,28], several photoreceivers together with special data-processing algorithms [29,30], and a special optical fiber with weak fiber Bragg gratings (wFBGs) recorded in a fiber with a known periodicity [31,32,33,34]. The effect is achieved by using fiber coils in the cable in certain places or with some periodicity. This method of increasing the acoustic sensitivity does not exclude other existing methods and can be used together with them
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
