Patent ID: 6924960

Claim:
A method for writing servo tracks on a rotating magnetic disk medium, comprising: following a reference track comprising previously-written servo patterns; using a servo control loop while writing servo patterns at a first target track on the magnetic disk medium, the servo control loop having a closed-loop response and including a two-dimensional state compensator comprising at least first and second inputs and first and second outputs, said first input configured to receive timing error signals, said first output comprising control signals for a controlled oscillator, said second output comprising first timing state variables corresponding to said first target track, said second input configured to receive timing state variables corresponding to said reference track; storing said timing state variables corresponding to said first target track as first stored timing state variables; and following said first target track using the servo control loop while writing servo patterns defining a second target track while providing said first stored timing state variables to said second input of said two-dimensional state compensator.