Breaking through the bandwidth barrier in distributed fiber vibration sensing by sub-Nyquist randomized sampling

2017/01/06 by Zhang, Jingdong, Zhu, Tao, Zheng, Hua +3
#FOS: Physical sciences #Instrumentation and Detectors (physics.ins-det)

paper · doi:10.48550/arxiv.1701.01522

Abstract

The round trip time of the light pulse limits the maximum detectable frequency response range of vibration in phase-sensitive optical time domain reflectometry (ϕ-OTDR). We propose a method to break the frequency response range restriction of ϕ-OTDR system by modulating the light pulse interval randomly which enables a random sampling for every vibration point in a long sensing fiber. This sub-Nyquist randomized sampling method is suits for detecting sparse-wideband-frequency vibration signals. Up to MHz resonance vibration signal with over dozens of frequency components and 1.153MHz single frequency vibration signal are clearly identified for a sensing range of 9.6km with 10kHz maximum sampling rate.

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