Locating weak changes in a multiple scattering environment

Thomas Planes , Éric Larose , Vincent Rossetto (1)

1 LPM2C - Laboratoire de physique et modélisation des milieux condensés

We present an imaging technique allowing to locate a weak perturbation appearing in a multiple scattering environment. This technique is based on the direct dependence in space and time of the coda (diffuse waves) decorrelation resulting from the apparition of an extra scatterer, which one wishes to image. The inverse problem solution – the location and scattering cross section of the defect – is obtained using a maximum likelihood computation. The LOCADIFF technique has been applied to locate a millimeter change in concrete using ultrasounds with a precision of the order of one centimeter. The size of the defect is comparable to the size of the heterogeneities constituting the sample.

Mots clés: non destructive testing; multiple scattering; coda; ultrasounds

Domaines: Acoustique [physics.class-ph]

Thomas Planes, Éric Larose, Vincent Rossetto. Locating weak changes in a multiple scattering environment. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00811296⟩