Ultra-high Frequency Vibration Measurement using Fading Suppressed Coherent φ-OTDR with Randomized Sampling

Abstract

By applying randomized sampling to interference fading suppressed coherent phase-sensitive optic time domain reflectometry (φ-OTDR) system, quantitative vibration signal measurement with much higher frequency than the Nyquist sampling theorem determined upper limit was demonstrated.

Activation Function Dynamic Averaging as a Technique for Nonlinear 2D Data Denoising in Distributed Acoustic Sensors

“…Distributed fiber optic sensors capable of recording events at a high frequency are of particular interest. As the frequencies detected by the instruments of this type in most cases turn out to be acoustic, such distributed sensors have also become known as acoustic (Distributed Acoustic Sensors-DAS) [5][6][7][8][9][10][11][12]. Since they make it possible to register the optical fiber longitudinal deformation changes at each point with frequencies from units of hertz to tens of kilohertz, it is not surprising that their use was not limited to the quite obvious functions of protection of perimeters, pipelines, and critical infrastructure facilities, but began to develop towards metrology and flaw detection.…”