Patent ID: 7639447

Claim:
A disk drive that compensates for servo track squeeze, the disk drive comprising: a disk having tracks, the tracks including a servo sector having servo bursts spaced sequentially around a circumference of the track for use in track following; a head to track-follow on the track, wherein track following includes the head reading the servo bursts; and a processor to compensate for track squeeze by implementing operations including: determining a track squeeze value for the servo sector based upon reading the servo bursts; determining a position error signal (PES) value for the servo sector based upon the read servo bursts; estimating a Squeeze Correction Coefficient (SCC) to account for PES sensing gain variation associated with the servo sector; calculating a squeeze corrected PES value based upon the SCC and the PES value, wherein the squeeze corrected PES value is calculated by an equation: Squeeze Corrected PES Value=SCC(z)*PES value(z), wherein z=position and SCC(z)=(|N|+|Q|)/(|N| nominal +|Q| nominal ), where N and Q are burst measurements at position z; and utilizing the squeeze corrected PES value in servo control.