Evaluation of Distributed Acoustic Sensing (DAS) Systems with Polarization Diversity for Railway Infrastructure: Effects of Fiber Type and Installation Conditions on System Performance
Abstract
Distributed Acoustic Sensing (DAS) systems based on ϕ-OTDR are increasingly used for real-time infrastructure monitoring, but their performance is limited by coherent and polarization fading, which create signal blind spots along the fiber. This study evaluates two coherent-detection DAS architectures-with and without polarization diversity-together with the influence of optical cable type and ground-coupling method, in an operational railway environment. Field experiments were conducted along a 40 km SNCF (Société Nationale des Chemins de fer Français) railway line using train passages as excitation sources, complemented by controlled sledgehammer tap tests on a 500 m calibration platform connecting four fiber configurations (telecom vs. sensing cables, buried vs. duct-installed). Signal amplitude, differential phase, and phase Median Absolute Deviation (MAD) were used to quantify sensing performance. Polarization diversity reduced the fraction of faded signals below -40 dB from approximately ≈8.4% to ≈1% of the fiber length and improved the Phase Stability Index (PSI) from ≈6 dB to ≈10 dB at 20 km, significantly mitigating polarization-induced signal dropouts across the 40 km span. Among the tested cables, the tight-buffered sensing fiber directly buried in the ground consistently provided the strongest and most stable response, while telecom fiber installed in a High-Density Polyethylene (HDPE) duct showed the weakest coupling. These results demonstrate that combining polarization-diversity detection with an optimized fiber-cable coupling strategy substantially improves the robustness of DAS for railway infrastructure monitoring
Related
- Blue carbon development and ecosystem services in oligotrophic environments: the case for a shallow coastal installation on the shelf off Tenerife (Canary Islands)
- Post-installation sustainability of small-scale biogas programs: a mini review conceptual model
- Automated Installation Checking and Hanger Pre-Adjustment for Stone Curtain Walls Based on UAV Photogrammetry and Terrestrial Laser Scanning.
- Development and Evaluation of Filtration Performance of ZnO-Doped PEI Composite Membranes
- A cloud-native framework for seismic waveform data quality assessment: Performance evaluation under equivalent resource constraints
BibTeX
@article{chedid2026evaluation,
title = {{Evaluation of Distributed Acoustic Sensing (DAS) Systems with Polarization Diversity for Railway Infrastructure: Effects of Fiber Type and Installation Conditions on System Performance}},
author = {Alex Chedid and Ali Kabalan and José Grand and Tarik Hammi and Gabriel Papaiz Garbini and Ianis Gaudot and Adnand Bitri and François Bretaudeau and Elie Awwad and Renaud Gabet},
journal = {Sensors},
year = {2026},
month = oct,
doi = {10.1117/12.3062236.},
url = {https://hal.science/hal-05841114v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Evaluation of Distributed Acoustic Sensing (DAS) Systems with Polarization Diversity for Railway Infrastructure: Effects of Fiber Type and Installation Conditions on System Performance
AU - Alex Chedid
AU - Ali Kabalan
AU - José Grand
AU - Tarik Hammi
AU - Gabriel Papaiz Garbini
AU - Ianis Gaudot
AU - Adnand Bitri
AU - François Bretaudeau
AU - Elie Awwad
AU - Renaud Gabet
PY - 2026
DA - 2026/10/01
JO - Sensors
DO - 10.1117/12.3062236.
UR - https://hal.science/hal-05841114v1
AB - Distributed Acoustic Sensing (DAS) systems based on ϕ-OTDR are increasingly used for real-time infrastructure monitoring, but their performance is limited by coherent and polarization fading, which create signal blind spots along the fiber. This study evaluates two coherent-detection DAS architectures-with and without polarization diversity-together with the influence of optical cable type and ground-coupling method, in an operational railway environment. Field experiments were conducted along a 40 km SNCF (Société Nationale des Chemins de fer Français) railway line using train passages as excitation sources, complemented by controlled sledgehammer tap tests on a 500 m calibration platform connecting four fiber configurations (telecom vs. sensing cables, buried vs. duct-installed). Signal amplitude, differential phase, and phase Median Absolute Deviation (MAD) were used to quantify sensing performance. Polarization diversity reduced the fraction of faded signals below -40 dB from approximately ≈8.4% to ≈1% of the fiber length and improved the Phase Stability Index (PSI) from ≈6 dB to ≈10 dB at 20 km, significantly mitigating polarization-induced signal dropouts across the 40 km span. Among the tested cables, the tight-buffered sensing fiber directly buried in the ground consistently provided the strongest and most stable response, while telecom fiber installed in a High-Density Polyethylene (HDPE) duct showed the weakest coupling. These results demonstrate that combining polarization-diversity detection with an optimized fiber-cable coupling strategy substantially improves the robustness of DAS for railway infrastructure monitoring
SN - 1424-8220
ER -