Numerical simulations of ultrasonic array imaging of highly scattering materials

A Finite Element modelling framework is outlined that enables the investigation of ultrasonic array imaging within highly scattering, polycrystalline materials. Its utility is demonstrated by investigating the performance of arrays, within both single and multiple scattering media. By comparison to well-established single scattering models, it is demonstrated that FE modelling can provide new insights to study the stronger scattering regimes. In contrast to established single scattering results, Signal-to-Noise Ratio (SNR) no longer increases monotonically with respect to increasing aperture, which suggests that maximum apertures are not necessarily optimal. Furthermore, by measuring the SNR of the individual transmit receive combinations of the array, it is found that through separating the emitter and receiving source, it is possible to reduce the received backscatter.