Self-Optimized Vibration Localization Based on Distributed Acoustic Sensing and Existing Underground Optical Cables

As the most common member of the underground pipeline, optical cable has already spread throughout the urban region. By combining the distributed acoustic sensing (DAS) system with the existing optical cables, it is possible to monitor all vibration events around the cable path. DAS data is commonly used to obtain the position of cable section under disturbance and describe the intensity or type of vibration. If the location of the vibration source relative to the optical cable can be further obtained, it will be able to realize the trajectory tracking of the ground target, which would be more conducive to the identification and early warning of external threats to the pipelines. This paper proposes a series of self-optimized methods such as adaptive short-time energy (ASTE), quality factor of fitting (QFF) based fitting optimization, joint localization by multi-samples (JLM), etc., which overcome the influence of the heterogeneous underground medium in field environment, achieving precise localization result on the vibration source with a vertical offset over 60 m. The proposed method provides a promising option for early warning of external threats to these existing underground pipelines without any extra reconstruction work.