Source localization on solids utilizing time-frequency analysis of parameterized warped signals

We propose a new approach for source localization on solids with applications to human-computer interface. We analyze the wave propagation of flexural modes of vibration, generated by an impact on a solid surface, to characterize the dispersive linear time-varying system having non-linear phase response. We show that a difference in dispersion between two signals propagating through solids can be mapped directly to the relative propagation distance if the signals are appropriately time-warped. We then exploit this important property for source localization by computing the similarity of the warped signals in the time-frequency domain. As the proposed source localization algorithm jointly estimates warping-based polynomial parameters and source location, the method does not require pre-calibration.