Time-domain shifting-assisted cepstrum method for complex vibration signal positioning in forward-transmission...

Area of Science:

• Geophysics
• Civil Engineering
• Signal Processing

Background:

• Aging urban underground pipelines face increasing risks, necessitating advanced monitoring solutions.
• Conventional methods for pipeline monitoring lack the necessary coverage and scalability.
• Forward-transmission distributed vibration sensing (FTDVS) offers real-time condition assessment but struggles with overlapping vibration events.

Purpose of the Study:

• To develop a novel method for accurate multi-point positioning of vibration events in FTDVS systems.
• To overcome the limitations of existing positioning techniques when multiple vibration signals overlap in frequency.

Main Methods:

• A time-domain shifting-assisted cepstrum method was proposed.
• This method extracts primary delays by suppressing dominant components via time-domain shifting.
• Residual signals are analyzed to recover secondary delays for precise event localization.

Main Results:

• Proof-of-concept experiments were conducted on a 34 km sensing fiber.
• The method demonstrated reliable multi-point positioning under various scenarios.
• Positioning accuracies as fine as 12.7 m were achieved.

Conclusions:

• The proposed method effectively addresses the challenge of locating multiple overlapping vibration events.
• This advancement significantly enhances the practical applicability of FTDVS for infrastructure monitoring.
• The technique is highly relevant for real-time pipeline surveillance, security monitoring, and smart city assessments.