Much work has been performed modeling thin anisotropic materials for use in nondestructive testing with plane wave excitation and detection [1–5]. There has been interest in the development of dispersion curve inversion and group velocity inversion procedures [6–8]. The general approach in many of these techniques is to align the excitation and detection along a known crystal axis, and analyze the detected signal to determine elastic constants, bond quality, thickness, or any number of other parameters [9–12]. Unfortunately, most of these approaches will fail to perform adequately when the target’s crystal axis is rotating with respect to the excitation axis, or when the coordinate frame of the crystal axis is unknown.</p
