A new level-set technique for the crack-detection problem

We present a new technique for recovering key characteristics of defects such as snake-like cracks from boundary electrical measurements. We propose a shape-based reconstruction algorithm adapting the level set techniques to the situation of modelling very thin shapes. Two level set functions are employed: the first one models the location and form of the crack, and the second one models its length and connectivity. Two Hamilton-Jacobi type equations are derived to describe the evolution laws for these two level set functions in order to minimize the least squares data misfit. Numerical experiments in 2D show the efficiency of this method for reconstructing disconnected cracks in the presence of measurement noise. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)