Methods of Distributed Acoustic Sensing Based on Rayleigh Scattering in Optical Fibers
Technology Category/Market
Technology: DAS in an optical fiber
Industry: Infrastructure (Hardware), Oil, Gas, Power & Utility, & etc.
Market: The global Distributed Acoustic Sensing (DAS) market is projected to grow at a CAGR of 11.58% during the forecast period from 2022 to 2030.
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Problem Statement
Distributed Acoustic Sensing (DAS) based on Rayleigh scattering in optical fibers is attractive for perimeter sensing as well as civilian applications including oil/gas/water pipeline monitoring, environment monitoring, & structural health monitoring.
Several versions exist in prior literature, but they are not preferred due to requirement of costlier equipment (high-speed digitizer), low signal to noise ratio & fading issues.
The present innovation aims to address the above issues.
Technology
Present invention describes a method of distributed acoustic sensing in an optical fiber based on low noise and machine learning
The method includes launching a pulse into an optic fiber from either end which is connected in a loop configuration.
Backscattered signals from the optical fiber are fed to an optical receiver through an optical circulator.
The phase signals are extracted by mixing the backscattered signals from the fiber with signals from a laser light source in a mixer, thereby performing a correlation operation.
Key Features/Value Proposition
Technical Perspective:
Perturbations to the optical fiber are identified by observing phase changes in the backscattered signal as shown in Fig. 2.
In the embodiments, detector comprises a machine learning module to sense perturbations or improve resolution or both
Industrial Perspective:
Enhanced spatial resolution & improved signal to noise ratio (SNR) leading to accurate detection of events.