Method of extracting disturbed position in φ-OTDR based on signal relevance evaluation

A theoretical analysis was conducted on the intrinsic bond between multi-point responses caused by the same single vibration in phase sensitive optical time-domain reflectometer (OTDR). Temporal similarity of signals collected from adjacent sample locations were investigated. Referring to correlation coefficient as well as the relative energy level, a method of extracting disturbed position in φ-OTDR based on signal relevance evaluation is proposed to perform fast screening of massive φ-OTDR raw data to pinpoint those signals with significance. As proof of concept, a manual excavation experiment was conducted along an oil pipeline, where on-site data was analyzed. The results showed that the proposed method can accurately screen out real vibration signals and filter out pure noise so that computation resources could be allocated with better rationality.