Abstract: A recording medium for a disk drive has a plurality of tracks defined by servo wedges that are written using a first servo spiral set, a second servo spiral set, and a correction factor that accounts for the differences in the first set of spirals and the second set of spirals. The differences may be differences in position values decoded from the first set of spirals and position values decoded from the second set of spirals or differences in timing values decoded from the first set of spirals and timing values decoded from the second set of spirals. The first servo spiral set is used in writing components of the servo wedges that define a first set of tracks. The second servo spiral set and the correction factor are used in writing components of the servo wedges that define a second set of tracks.

Abstract: In a disk drive, a wedge-based scheme is used to determine wedge offset correction values for a track of the disk drive. Correction values for the offset of each servo wedge are calculated wedge-by-wedge, based on the position error signal (PES) of the most recently measured servo wedge in combination with the measured PES of other servo wedges. To minimize transport delay of the servo, the majority of servo-control calculations may be pre-calculated prior to measuring the PES at the current wedge. Wedge offset correction values for a given servo wedge are corrected iteratively with each revolution of the storage disk.

Abstract: In a disk drive, a wedge-based scheme is used to determine wedge offset correction values for a track of the disk drive. Correction values for the offset of each servo wedge are calculated wedge-by-wedge, based on the position error signal (PES) of the most recently measured servo wedge in combination with the measured PES of other servo wedges. To minimize transport delay of the servo, the majority of servo-control calculations may be pre-calculated prior to measuring the PES at the current wedge. Wedge offset correction values for a given servo wedge are corrected iteratively with each revolution of the storage disk.