The Signal Processing Method of Mixed Interference Distributed Fiber-Optic Long-Distance Pipeline Leaks Detection System

摘要

A new measuring structure based on the principle of Sagnac and Mach-Zehnder mixed distributed fiber-optic interferometer can detect pipeline leakage and locate leakage point in real-time. But the actual pipeline leakage signal is nonlinear and tiny broadband signal, and there is a lot of background noise in the testing environment. The null spectrum extracted to decide the location of the leak is relatively difficult. In this paper, it's based on the discrete wavelet and least squares curve fitting method for leakage signal preprocessing. Reusing the signal through multi-scale decomposition of each signal multiplication method to determine leakage null spectrum, and the good result is achieved.