1. A system for measurement of surface and subsurface material flaw size which comprises, a. means for obtaining data as a function of a flaw in a medium, b. means to perform spectral analysis on said data, c. means to perform a cepstral analysis on said data, d. means responsive to the output of both (b) and (c) to provide a set of parameters; and e. means responsive to predetermined ones of said parameters to provide an estimated flaw length indication