Amplitude-based approach for detection and classification of hard-disc defect regions

A machine for classifying a defect region on a hard disc as associated with either thermal asperity (TA) or media defect (MD), the machine comprising:

• (a) means for generating a first measure based on (i) magnitudes of one or both of signal values corresponding to the defect region and corresponding expected signal values and (ii) signs of one or both of the signal values and the expected signal values;
• (b) means for generating a second measure based on the magnitudes of one or both of the signal values and the expected signal values, but not the signs of either the signal values or the expected signal values;
• (c) means for comparing the first and second measures;
• and
• (d) means for determining whether the defect region is associated with TA or MD based on the comparison of means (c).

A non-transitory machine-readable storage medium, having encoded thereon program code, wherein, when the program code is executed by a machine, the machine implements a method for classifying a defect region on a hard disc as associated with either thermal asperity (TA) or media defect (MD), the method comprising:

• (a) generating a first measure based on (i) magnitudes of one or both of the signal values corresponding to the defect region and corresponding expected signal values and (ii) signs of one or both of the signal values and the expected signal values;
• (b) generating a second measure based on the magnitudes of one or both of the signal values and the expected signal values, but not the signs of either the signal values or the expected signal values;
• (c) comparing the first and second measures;
• and
• (d) determining whether the defect region is associated with TA or MD based on the comparison of step (c).