利用单极性编码脉冲的海底光缆护套层故障探测方法

海底光缆的使用环境中存在随机扰动因素，故使用传统单脉冲电磁脉冲时域反射法进行护套层故障探测会受到大量随机噪声的干扰，探测波形难以辨识，故障探测效果较差。为改善探测效果，根据海底光缆护套层结构特性将其等效为带有随机扰动偏差的有耗非均匀传输线模型进行分析，提出了使用单极性编码脉冲作为探测信号的海底光缆护套层故障探测方案。通过理论分析和实验研究，证明与单脉冲探测方案相比，该方案可以在不降低空间分辨率的前提下有效降低测试系统噪声，获得较好的探测效果，满足海底光缆护套层故障探测要求。

Method of fault-detecting of submarine optic fiber cable sheath based on unipolar pulse-coding

Random perturbations exist in the working environment of submarine optic fiber cable, so using traditional single-pulse TDR to detect the fault of submarine optic fiber cable sheath can not get ideal waveform due to the interference of random noise, and fault detecting effect is unsatisfactory. To solve this problem, an equivalent circuit model of submarine optic fiber cable sheath was proposed based on the structural characteristics of submarine optic fiber cable sheath, which is equal to a lossy-nonuniform transmission line with random perturbations. And a fault-detecting method was put forward, which adopted unipolar coding pulse as detecting signal. Through theoretical analysis and experimental studies, this program can effectively reduce the nosie of system without reducing the spatial resolution and improve the system gain compared with single-pulse TDR. So the detecting result can be improved, and meet the requirements of submarine optic fiber cable sheath fault-detecting engineering.