Noise and fading reduction in a phase-OTDR system using a multi-strand optical fiber sensing cable

This paper introduces an innovative architecture, to the best of our knowledge, for a phase-OTDR sensing system, employing a multi-strand optical fiber cable as the sensing element. Within the cable, the fiber strands are interconnected to form a single serpentine-shaped fiber. The key advantage of this architecture lies in its ability to enhance the detection performance of a phase-OTDR system by reducing missing alarms caused by interference fading. Additionally, noise reduction can be achieved by aggregating the sub-traces corresponding to all fiber strands. To further enhance performance, we associate the use of a multi-pulse averaging method, which involves aggregating traces obtained using multiple probe pulses with varying temporal widths. The results obtained indicate that the performance of this architecture is closely related to the number of fiber strands and the number of probe pulses used. We expect that the proposed phase-OTDR architecture is particularly well-suited for effective distributed intrusion monitoring applications in short- to medium-range sensitive infrastructures where high security is paramount.