A simple method for pulse-echo thermal wave imaging of arbitrary-shaped subsurface scatterers in heterogeneous materials

We present a simple, general and computationally fast numerical method for pulse-echo thermal wave imaging of arbitrary-shaped subsurface scatterers in heterogeneous materials. In this method, the thermal wave theory is employed to determine the initial temperature distribution inside the materials shortly after pulse-best is applied. Then a technique, Effective Parameters for Interfacial Cells (EPIC), developed in connection with heat conduction [1-3], electrostatics [4-5] and incompressible fluid now [6], is extended to allow calculation of transient surface temperature distribution. The method is simpler and computationally faster than other numerical methods. We present representative results which could be used for non-destructive testing of subsurface defects.