A surface roughness analysis system and methods of analyzing surface roughness of a workpiece are presented. The surface roughness analysis system comprises a number of wave generators; a number of wave sensors; and an ultrasonic analysis system configured to receive material mechanical parameters for a workpiece, determine incident surface wave signal parameters for a source signal to be sent by the number of wave generators, and determine a cut-off wavelength using the material mechanical parameters, wherein the cut-off wavelength is a ratio of surface wavelength over incident wavelength.