AN IDENTIFICATION OF SCATTERERS USING TOPOLOGY OPTIMIZATION WITH 3D TIME DOMAIN BIEM

Abstract

We consider an identification of the number, shape and location of scatterers in a target object using scalar waves in anticipation of application to ultrasonic quantitative non-destructive estimate (QNDE). We calculate the scattering wave field numerically and introduce a objective functional which consists of the difference between the numerical and observational scattering field. The scatterers are determined as the minimizer of the objective functional. We also consider the topology change of the target object in order to execute the identification considering the generation and extinction of scatterers. We define a topology derivative as the sensitivity of the objective functional with respect to the topology change and execute the identification of the scatterers using the topology derivative via the level set method. We solved some numerical examples and determined the number, shape, and location of scatterers at the same time.