A disk drive includes a rotatable data storage disk, a transducer, an
actuator, and a controller. The disk includes information and data tracks
that are defined thereon. The transducer is configured to read the
information from the disk. The actuator is configured to position the
transducer relative to the data tracks. The controller is configured to
measure timing between particular information on the disk, to estimate
repeatable runout of the disk based on the measured timing, and to
compensate for repeatable runout of the disk responsive to the estimated
repeatable runout while positioning the transducer relative to a selected
track.