一种减小Φ-OTDR光纤扰动传感系统中频率漂移误差的新定位算法

The frequency drift of laser greatly affects the positioning accuracy of the phase-sensitive optical time-domain reflectometer (Φ-OTDR) distributed optical fiber disturbance sensing system. So a new localization algorithm based on spectrum analysis was proposed to replace the traditional time-domain moving difference and average algorithm. The collected scattering curve data was taken as the Fourier transform, and then the characteristic frequency interval was selected to calculate the location result, which can effectively suppress the positioning error caused by the laser frequency drift. In addition, a prototype of 8 km was built to test the positioning algorithm. Test results indicate that the signal-to-noise ratio of the final system is improved, and the effectiveness of the algorithm is verified.