posted on 2024-10-29, 16:00authored byQiang Yang, Weilin Xie, Congfan Wang, Bowen Li, Xin Li, Xiang Zheng, Wei Wei, Yi Dong
In distributed fiber-optic sensing based on optical frequency domain reflectometry (OFDR), Doppler frequency shifts due to the changes of disturbances during one sweep period introduce demodulation errors that accumulate along both the distance and time, impairing the sensing performance. Here, we report distributed dynamic strain sensing using Doppler-shift-immune phase-sensitive OFDR based on frequency-tracking and spectrum-zooming with ultra-weak reflection array. Theoretical study has been carried out with the introduction of mismatch coefficient, unveiling quantitatively the impact of Doppler shift. Following a numerical analysis of the proposed method, a retained precision has been experimentally verified regardless of the position mismatch due to the Doppler effect. Doppler-shift-immune sensing for dynamic strains covering continuous spatial resolution over a distance of 1000 m with a 2.5 cm sensing spatial resolution has been demonstrated, verifying the high fidelity promised by the proposed method.
History
Disclaimer
This arXiv metadata record was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv.