Patent ID: 7576942

Claim:
A data storage system comprising: a data storage medium comprising: a plurality of data tracks defined by a width d 1 ; and a plurality of permanent servo sectors pre-recorded on the storage medium, wherein each servo sector includes a first null burst that includes a first portion and second portion and a null burst that includes a third portion and fourth portion, wherein each portion of the null bursts is defined by a width d 2 that is greater than the width d 1 of the data tracks; a transducer head that is positionable over a desired track and finely positionable based on readback signals generated in response to the permanent servo sectors; a servo demodulator connected to receive readback signals generated by the transducer head and to generate a first position error signal in response to the first null burst and a second position error signal in response to the second null burst, and uses region information provided by the first and second position error signals to generate a first region-based displacement estimate and a second region-based displacement estimate, wherein the servo demodulator calculates a final displacement estimate based on the first and second region-based displacement estimates; and a controller for generating servo control instructions to control the positioning of the transducer head over a desired track based on the final displacement estimate generated by the servo demodulator.