Solution of a non-linear inverse problem to identify the surface normal velocity of ultrasound transducers

Using the spatial impulse response, it is possible to predict the temporal and spatial pressure field distribution of an ultrasound transducer as well as the output signal of the transducer operated in pulse=echo mode for a well-known target under investigation. This prediction requires an a priori chosen surface normal velocity of the active transducer surface, which often does not coincide with the actual surface normal velocity. By contrast, in our work we solve an inverse problem, which yields a spatially discretized weighting function (distribution) for the surface normal velocity of the active transducer surface. Furthermore, this estimated distribution of the surface normal velocity is used to compare simulated data to measured output signals for a transiently excited ultrasound transducer for known targets.