A disturbance localization method based on region segmentation and FNLM algorithm for Φ-OTDR

Aiming at the problem of the low real-time performance of phase-sensitive optical time-domain reflectometer (Φ-OTDR) technique in disturbance localization, a localization method based on the combination of region segmentation and fast non-local means (FNLM) algorithm is proposed. By dividing the whole link of the fiber optic into regions, the disturbance region is quickly located. The FNLM algorithm is introduced to process the signals of the perturbed target region, which is intended to further achieve the precise positioning of the perturbation location. Experiments are conducted using a Φ-OTDR system to test the localization of disturbances at three frequencies. The results show that the region segmentation approach can reduce the computation to a large extent, resulting in an order-of-magnitude reduction in processing time. The introduction of the FNLM algorithm enables the system to maintain a low positioning error of 2.47 m while positioning quickly.