A method of measuring a track value is shown. The track value is related
to track mis-registration, and is compared to a track value limit to
assess a condition of the track. In example embodiments, the track value
is determined as a function of multiple position error signals from
previous wedges in the track. During a self servo writing operation, the
track value and the track value limit are used to selectively perform a
recovery action. In example embodiments, the track value limit is
dynamically adjusted.