A disk drive comprising a moveable head, a disk, and a servo controller
that implements servo control techniques to preserve PES continuity
during track following operations is disclosed. The disk includes a
plurality of tracks in which a substantial majority of the tracks include
a plurality of servo sectors having a plurality of servo bursts that are
utilized in track following operations. The servo controller controls
track following operations with the moveable head and implements
operations to preserve PES continuity during track following. These
operations include: dividing tracks of the disk into a plurality of zones
wherein each zone includes zone boundaries; and utilizing a PES equation
for each zone to generate a PES value based upon read servo bursts
wherein each zone PES equation includes a normalizing factor to account
for boundary conditions associated with zone boundaries to preserve PES
value continuity between zones.