A failure classifier based on the ratio of harmonic components

摘要

PROBLEM TO BE SOLVED: To provide a method for detecting and classifying at least one defect in a medium.;SOLUTION: The method comprises writing a periodic pattern to a medium, and comparing the magnitude of a readback waveform with a defect threshold to detect the presence or absence of a defect in the medium. When one defect is detected, at least two harmonics are detected from the readback waveform, and the defect is classified by comparing the ratio of their magnitudes.;COPYRIGHT: (C)2014,JPO&INPIT