The present invention may be embodied in a method for preventing radial error
propagation during self-servowriting of concentric tracks on a magnetic disk in
a disk drive. Each written track comprises a plurality of embedded servo sectors
that define a circumferential path and that eventually form corresponding servo
wedges extending radially across the magnetic disk such that each servo sector
t of a track corresponds to a particular servo wedge. In the method comprising,
track following is performed along a previously written track and a position error
signal is determined for each servo sector. A correction value is recursively estimated
for each servo sector of an adjacent track. The correction value is for use in
correcting a position error signal determined using the corresponding servo sector
of the adjacent track to prevent radial error propagation from previously written
track to the adjacent track.