Signal Separation of Phase-sensitive Optical Time-domain Reflectometry Considering Thermo-mechanical Coupling and 3D Data Matching

This paper aims to enhance the signal separation accuracy of phase-sensitive optical time-domain reflectometry (Phi-OTDR) under thermo-mechanical coupling (TMC). For this purpose, the Phi-OTDR signal was firstly separated by genetic algorithm-empirical mode decomposition-nonnegative matrix factorization (GA-EMD-NMF). Then, the Kalman-proportional-integral-derivative (PID) method was introduced to further separate the data. Taking the TMC as the input, a feedback model was constructed by the genetic algorithm-radial basis function (GA-RBF) to decouple the TMC. To tackle the 3D Phi-OTDR data, a 3D speeded up robust features (SURF) method was developed to reconstruct the box filter and Gaussian pyramid based on the features of the 3D data, thereby enhancing the positioning accuracy of Phi-OTDR signal. Later, several experiments were carried out in a semi-anechoic room, which proved that the proposed method outperforms the traditional methods. The research findings shed new light on signal separation of Phi-OTDR.