Diffraction length of localized waves generated by dynamic apertures

A definition of the diffraction length characterizing the propagation of localized wave pulses launched from dynamic apertures is provided. Our inference of the diffraction range is based on an analysis of the spectral depletion of the spatial frequency components of the pulse as it propagates away from its source. We demonstrate the efficacy of our procedure by showing that it is capable of capturing some decay features of localized wave pulses that may be missed by other approaches.