On a linearized inverse scattering model for a three-dimensionalflaw embedded in anisotropic advanced composite materials

A three-dimensional linearized model to reconstruct the flaw in advanced anisotropic composite materials is developed. The inversion scheme takes the form of an integral equation, which is discretized by means of the method of moments. The measured data are then inverted by means of the conjugate gradient (CG) fast Fourier transform algorithm, which incorporates Levenberg-Marquardt regularization and adaptive preconditioning schemes. The reconstruction of the flaw based on simulated as well as measured data, along with some of the salient features of the newly developed CG algorithm are presented