基于端点检测与互相关时延估计的精准光纤扰动定位检测

Accurate optical fiber disturbance localization detection based on endpoint detection and cross-correlation delay estimation

针对双马赫曾德干涉仪型分布式光纤扰动传感系统无法实时高效精准定位的检测难题,提出了一种快速端点检测与互相关时延估计相结合的快速精准定位检测方案。采用一种改进型的巴特沃斯滤波端点检测算法,实现了对原始干涉扰动信号的精准快速扰动端点检测,以获取干涉信号中的高频扰动部分,剔除无效低频干扰数据。基于互相关时延估计算法,对获取的两路高频扰动信号进行固定时延求解,并根据扰动位置与固定时延之间的关系解调出作用于传感光纤链路上的具体扰动位置。实验测试结果表明,在总长为1.1 km的光纤链路上,双马赫曾德干涉仪型分布式光纤扰动传感系统的定位标准差仅为5.2 m。该定位检测方案具有较高的定位精度和较好的信号处理实时性。

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.