Patent ID: 8891194

Claim:
A disk drive comprising: a disk comprising a plurality of servo tracks, wherein each servo track comprises a plurality of servo sectors; a head actuated over the disk; and control circuitry operable to: measure a position y of the head based on the servo sectors; adjust the measured position y of the head based on: z 1 =y+c 1( y ) where z1 represents a first adjusted position and c1(y) represents first correction values; adjust the first adjusted position z1 based on: z 2 =z 1 +c 2( z 1) where z2 represents a second adjusted position and c2(z1) represents second correction values; combine the first and second correction values based on: c 3( y )= c 1( y )+ c 2( y+c 1( y )); and adjust the measured position y of the head based on: z 3 =y+c 3( y ) where z3 represents a third adjusted position comprising the adjustment based on c1(y) and the adjustment based on c2(y), and c3(y) represents third correction values.