Abstract: A mechanism for servowriting on a storage medium of a storage device. The storage device has a transducer and a servo loop for positioning the transducer with respect to the storage medium. At least one transition is written on a track of the storage medium, while servoing on other transitions previously recorded on the storage medium. A reference waveform is derived as a function of a closed loop response of the servo loop and a position error waveform. The position error waveform corresponds to one or more position errors of the transducer relative to the previously recorded transitions. The reference waveform is usable in writing subsequent tracks on the storage medium. Using the reference waveform for writing subsequent tracks provides a substantial rejection of mechanical disturbances by the servo loop.

Abstract: Improvements in placement of timing patterns in self servo writing include correcting for random and systematic errors due to geometric effects. In a disk drive having a recording head with separate read and write elements, a method for determining separation between the elements and for correcting for such errors as a function of skew angle between the head and the disk. Errors resulting from misalignment and non-parallelism of the elements as well as misalignment of the head on it its actuator are also detected and corrected. Errors due to changes in rotational velocity of the disk and misplacement of timing patterns with respect to adjacent timing patterns are detected and corrected. In general, a single revolution process may be used to both write and detect random errors on each track and corrected on subsequent tracks.