Phase root seeking and the Cramer-Rao-Lower bound for strain estimation

With the Phase-Root-Seeking algorithm a new and very fast algorithm for time delay estimation was recently introduced, permitting the estimation of strain images in real-time. In this paper the accuracy of the real-time strain imaging concept is investigated by the most rigorous approach, i.e. a comparison to the theoretical accuracy limit: the Cramer-Rao-Lower-Bound. Simulations show, that this limit can be approximately reached by carefully selecting window length and window shift for time delay estimations and using a generalized least square estimator for the estimation of strain from time delays