Spacing measurement improvement in the presence of track mis-registration

摘要

Techniques for determining a relative spacing between a read head and a surface of a magnetic data storage device may use at least two magnetic spacing measurement patterns. A first magnetic spacing measurement pattern may be offset from a center of a data track by a first offset value and a second magnetic spacing measurement pattern may be offset by a second, different, offset value. A processor may determine a first harmonic tone and a second harmonic tone from each of the first and second magnetic spacing measurement patterns. The processor also may determine respective ratios between amplitudes of the first and second harmonic tones for each of the first and second magnetic spacing measurement patterns. The processor may determine which ratio is greater, and may utilize the greater ratio when determining relative spacing between the read head and the surface of the magnetic data storage device.

主权项

1. A storage device comprising:
a magnetic data storage device comprising a data track comprising a magnetic spacing measurement pattern grouping comprising a first magnetic spacing measurement pattern offset from a center of the data track by a first offset value and a second magnetic spacing measurement pattern offset from the center of the data track by a second, different offset value; a read head; and at least one processor configured to:
control the read head to pass over the data track including the first magnetic spacing measurement pattern and the second magnetic spacing measurement pattern;receive a signal indicative of magnetic transitions sensed by the read head during the pass;determine, for each of the first magnetic spacing measurement pattern and the second magnetic spacing measurement pattern, a respective first harmonic tone based on the signal;determine, for each of the first magnetic spacing measurement pattern and the second magnetic spacing measurement pattern, a respective second harmonic tone based on the signal;determine, for each of the first magnetic spacing measurement pattern and the second magnetic spacing measurement pattern, a ratio of the respective first harmonic tone and the respective second harmonic tone;determine a maximum ratio; andutilize the maximum ratio to determine a relative spacing between the read head and a surface of the magnetic data storage device.