Accurate optical fiber disturbance localization detection based on endpoint detection and cross-correlation delay estimation
To address the challenge of achieving real-time,efficient,and accurate positioning in the dual Mach-Zehnder interferometer-based distributed optical fiber disturbance sensing system,a rapid and precise positioning detection scheme that integrates fast endpoint detection with cross-correlation delay estimation is proposed.By employing an enhanced Butterworth filtering endpoint detection algorithm,the precise and rapid disturbance endpoint detection in the original interference signal is achieved successfully.This allows us to isolate the high-frequency disturbance components while eliminating invalid low-frequency interference data.Utilizing the cross-correlation delay estimation algorithm,the fixed delay between the captured high-frequency disturbance signals is determined.Furthermore,the specific disturbance position along the sensing optical fiber link is demodulated,based on the relationship between the disturbance position and the fixed delay.Experimental test results demonstrate that the positioning standard deviation of our system is merely 5.2 m over a 1.1 km optical fiber link.This positioning detection scheme exhibits high positioning accuracy and excellent real-time signal processing capability.
fiber sensingdual Mach-Zehnder interferometerButterworth filtercross-correlation time delay estimationpositioning detection