Disk drive correcting track ID in response to an estimated radial location and a burst PES

1. 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.

2. The disk drive as recited in claim 1 , wherein the control circuitry is operable to determine the detected track ID is corrupt based on a difference between a detected radial location based on the detected track ID and the burst PES, and the estimated radial location.

3. The disk drive as recited in claim 1 , wherein the control circuitry is operable to generate the corrected track ID by subtracting the burst PES from the estimated radial location.

4. The disk drive as recited in claim 1 , wherein the control circuitry is operable to generate the corrected track ID by subtracting the burst PES from the estimated radial location and integer dividing the result by a value representing a number of steps between consecutive servo tracks.

5. A method of operating a disk drive, the disk drive comprising a head and a disk, the 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, the method comprising:

generating an actuator control signal for actuating the head over the disk;

generating an estimated radial location of the head in response to the actuator control signal;

detecting a Gray coded track ID from reading one of the servo sectors;

decoding the detected Gray coded track ID into a detected track ID;

generating 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:

generating a corrected track ID using the estimated radial location and the burst PES; and

adjusting the actuator control signal in response to the corrected track ID and the burst PES.

6. The method as recited in claim 5 , further comprising determining the detected track ID is corrupt based on a difference between a detected radial location based on the detected track ID and the burst PES, and the estimated radial location.

7. The method as recited in claim 5 , further comprising generating the corrected track ID by subtracting the burst PES from the estimated radial location.

8. The method as recited in claim 5 , further comprising generating the corrected track ID by subtracting the burst PES from the estimated radial location and integer dividing the result by a value representing a number of steps between consecutive servo tracks.