Temperature-Strain Decoupling Sensing System Based on BOTDR Combined with Raman Scattering
Acquiring Brillouin frequency shift in a single-mode fiber while utilizing Raman temperature measurement in a parallel multi-mode fiber is a common engineering approach for a simultaneous measurement of both temperature and strain.Nevertheless,the method increases both the complexity of the configuration in the sensing system and the application cost.A measurement system on single-mode fiber with single core which combines Raman backscattering sensing and Brillouin frequency shift measurement is constructed.The sys-tem utilizes time-division multiplexing technology based on a dual-channel optical switch to realize a simultaneous measurement and de-coupling of temperature and strain.The principle of two-parameter measurement is analyzed and the Raman-assisted BOTDR experiment system is constructed.Wavelet denoising algorithm is utilized for data processing.Experiment results demonstrate that the system real-ized a 3 m spatial resolution on a 9 km measurement range.The measured temperature fluctuation range is±1.5 ℃ with a root mean square error(RMSE)of 0.808 ℃.The measured strain fluctuation range is±117 με with a RMSE of 72.04 με.The result demonstrates the capability of Raman-assisted BOTDR temperature and strain measurement system for solving the cross sensitive problem in single-mode-fiber-based sensing,which provides a theoretical basis for the subsequent engineering applications and solutions.
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维普
