Patent ID: 8553351

Claim:
A disk drive comprising: a disk comprising a plurality of servo tracks defined by a plurality of servo sectors, each servo sector comprising a Gray coded track ID and servo bursts; a head; an actuator for actuating the head over the disk; and control circuitry operable to: generate an actuator control signal applied to the actuator; generate an estimated radial location of the head in response to the actuator control signal; detect a Gray coded track ID from reading one of the servo sectors; decode the detected Gray coded track ID into a detected track ID; generate a burst position error signal (PES) from reading the servo bursts in the servo sector, wherein the burst PES represents a detected fractional servo track offset of the head; and when the detected track ID is corrupt: generate a corrected track ID using the estimated radial location and the burst PES; and adjust the actuator control signal in response to the corrected track ID and the burst PES.