Detection of Ground Movement using the Shape of Brillouin Spectrum

Edouard Buchoud (1, 2) , Sylvain Blairon (1) , Guy d'Urso (1) , Jean-Marie Henault (1) , Alexandre Girard (1) , Jerome I. Mars (2) , Valeriu Vrabie (3)

1 EDF - EDF
2 GIPSA-SIGMAPHY - GIPSA - Signal Images Physique
3 CRESTIC - Centre de Recherche en Sciences et Technologies de l'Information et de la Communication - EA 3804

Distributed Optical Fiber Sensing systems (DOFSS) are composed by optical fibers wrapped in strain sensing cables, coupled with Brillouin interrogators. DOFSS are increasingly used for Structural Health Monitoring (SHM) as they can provide continuous strain profiles along the optical fiber localized in the structure. Raw Brillouin measurements consist in gain - frequency curves with a Lorentzian shape. Strain is generally assessed thanks to the abscissa of the maximum of the gain curve. Two new factors are introduced. They are sensitive to asymmetry and broadening of the Brillouin gain curve which can highlight strain gradient within the spatial resolution of the interrogator. These parameters could be used to detect more efficiently local events and improve instrument algorithm.

Domaines: Traitement du signal et de l'image [eess.SP]; Traitement du signal et de l'image [eess.SP]

Edouard Buchoud, Sylvain Blairon, Guy d'Urso, Jean-Marie Henault, Alexandre Girard, et al.. Detection of Ground Movement using the Shape of Brillouin Spectrum. 18th European Meeting of Environmental and Engineering Geophysics, Sep 2012, Paris, France. pp.B32. ⟨hal-00728409⟩