  This work presents a concept for the localisation of Lamb waves using a
Passive Phased Array (PPA). A Warped Frequency Transformation (WFT) is applied
to the acquired signals using numerically determined phase velocity information
to compensate for signal dispersion. Whilst powerful, uncertainty between
material properties cannot completely remove dispersion and hence the close
intra-element spacing of the array is leveraged to allow for the assumption
that each acquired signal is a scaled, translated, and noised copy of its
adjacent counterparts. Following this, a recursive signal-averaging method
using artificial time-locking to denoise the acquired signals by assuming the
presence of non-correlated, zero mean noise is applied. Unlike the application
of bandpass filters, the signal-averaging method does not remove potentially
useful frequency components. The proposed methodology is compared against a
bandpass filtered approach through a parametric study. A further discussion is
made regarding applications and future developments of this technique.
