Trajectory monitoring method based on optical sensing spectral energy and adaptive threshold

Distributed optical fiber sensing technology is widely used in structural health monitoring, security systems and other fields. The traditional monitoring method of electrical measurement can ensure monitoring accuracy of train trajectory, while this method is easily affected by thunderstorm weather. In order to simultaneously improve the anti-interference ability and monitoring accuracy, this paper proposes a trajectory monitoring method based on optical sensing spectral energy and adaptive threshold. This method only needs to monitor the backward Rayleigh scattering optical signal of a redundant communication fiber, and perform Fourier transform and spectral energy operation to analyze vibration signals of the entire line. An adaptive threshold algorithm is utilized to autonomously locate fiber position of the train and form a spatial-temporal trajectory map. The method proposed in this paper is a passive monitoring method using optical sensing, which greatly improves system's ability to resist electromagnetic interference, reduces the monitoring cost of the entire system, and effectively ensures the positioning accuracy. Experimental results demonstrate the effectiveness, safety, and accuracy of the train trajectory monitoring method based on optical sensing spectral energy and adaptive threshold.