公开(公告)号：US12117361B2

公开(公告)日：2024-10-15

申请号：US17908248

申请日：2022-03-23

Applicant: NANJING UNIVERSITY

Inventor： Yixin Zhang ,  Xiaohong Chen ,  Xuping Zhang ,  Shuai Tong ,  Lei Liang ,  Yiming Wan ,  Feng Wang

IPC: G01M11/00

CPC classification number: G01M11/3145

Abstract: A method for suppressing coherent and polarization-induced fading by simultaneous monitoring of loss and vibration is provided. By using merely common single-mode sensing fibers, the polarization diversity-based measurement method solves the conflict between Φ-OTDR and COTDR in terms of polarization state. In addition, the method not only achieves a better coherent fading noise suppression effect but also enhances the capability of recognizing small loss events in the monitoring of loss parameters. Meanwhile, the method can suppress the influence of coherent fading on the phase demodulation of Φ-OTDR and reconstruct a vibration signal with high fidelity in the monitoring of perturbation parameters, which can effectively reduce the error rate of external perturbation warning.