Field test and fading measurement of a distributed acoustic sensor system over a 50 km-long fiber

In this study, we present a direct detection distributed acoustic sensor based on phase-sensitive optical time domain reflectometer (φ-OTDR) with long sensing range and high signal-to-noise ratio (SNR), which is field-tested over a 50 kmlong fiber. Due to the random nature of Rayleigh backscattered light and fading phenomena, it is hard to characterize the performance of the system. For this reason, the performance of our sensor is specified in a statistical manner in which the mean SNR is determined using the histograms of the SNR. The SNR values are measured for identical acoustic signals in five different days, total of 48 hours and the SNR histograms are obtained for fiber distances of 100 m, 12 km, 21 km, 30 km, 40 km and 50 km. The system is field-tested using external disturbances that are generated from a 50-Hz vibrator. The SNR values are extracted from the power spectral density (psd) of the collected data over the monitored fiber span. Our results show that the φ-OTDR system exhibits a mean SNR of 22.5 dB at 50 km distance.

[1]  Yahei Koyamada,et al.  Characteristics and reduction of coherent fading noise in Rayleigh backscattering measurement for optical fibers and components , 1992 .

[2]  Xiaoyi Bao,et al.  Theoretical and Experimental Analysis of $\Phi $ -OTDR Based on Polarization Diversity Detection , 2016, IEEE Photonics Technology Letters.

[3]  Qing Bai,et al.  Distributed Fiber-Optic Sensors for Vibration Detection , 2016, Sensors.

[4]  Hao Feng,et al.  A Long Distance Phase-Sensitive Optical Time Domain Reflectometer with Simple Structure and High Locating Accuracy , 2015, Sensors.

[5]  Haniel Gabai,et al.  SNR characterization in distributed acoustic sensing , 2016, European Workshop on Optical Fibre Sensors.

[6]  X. Bao,et al.  High Sensitivity Distributed Vibration Sensor Based on Polarization-Maintaining Configurations of Phase-OTDR , 2011, IEEE Photonics Technology Letters.

[7]  Zuyuan He,et al.  Distributed Fiber-Optic Acoustic Sensor With Enhanced Response Bandwidth and High Signal-to-Noise Ratio , 2017, Journal of Lightwave Technology.

[8]  Xuping Zhang,et al.  Polarization dependence of phase-sensitive optical time-domain reflectometry and its suppression method based on orthogonal-state of polarization pulse pair , 2016 .

[9]  C. Svelto,et al.  Influence of the Laser Frequency Drift in Phase-Sensitive Optical Time Domain Reflectometry , 2019, Optics and Spectroscopy.

[10]  A. Eyal,et al.  Distributed acoustic sensing: How to make the best out of the Rayleigh-backscattered energy? , 2017, 2017 25th Optical Fiber Sensors Conference (OFS).

[11]  Trevor P. Newson,et al.  A distributed optical fibre dynamic strain sensor based on phase-OTDR , 2013 .

[12]  Qing Ye,et al.  Phase-sensitive OTDR system based on digital coherent detection , 2011, 2011 Asia Communications and Photonics Conference and Exhibition (ACP).

[13]  Xiaoyi Bao,et al.  Distributed Vibration Sensor Based on Coherent Detection of Phase-OTDR , 2010, Journal of Lightwave Technology.

[14]  S. Martin-Lopez,et al.  Comparison of the use of first and second-order Raman amplification to assist a phase-sensitive optical time domain reflectometer in distributed vibration sensing over 125 km , 2014, Other Conferences.

[15]  Z. N. Wang,et al.  Ultra-long phase-sensitive OTDR with hybrid distributed amplification. , 2014, Optics letters.

[16]  Lijing Li,et al.  Influences of laser source on phase-sensitivity optical time-domain reflectometer-based distributed intrusion sensor. , 2014, Applied optics.

[17]  A. Wójcik,et al.  Signal statistics of phase dependent optical time domain reflectometry , 2007 .

[18]  Jun Zhou,et al.  Interference-fading-free phase-demodulated OTDR system , 2012, Other Conferences.

[19]  Shengwen Feng,et al.  Phase-Sensitive Optical Time Domain Reflectometer Based on Phase-Generated Carrier Algorithm , 2015, Journal of Lightwave Technology.

[20]  Massimo L. Filograno,et al.  Coherent Noise Reduction in High Visibility Phase-Sensitive Optical Time Domain Reflectometer for Distributed Sensing of Ultrasonic Waves , 2013, Journal of Lightwave Technology.