Radial dependent low frequency repeatable run out compensation apparatus and method

An apparatus and method for tracking radially-dependent repeatable run-out in a disc drive having a servo loop for positioning a head over a rotating disc is provided. The disc includes multiple tracks. Radially-dependent repeatable run-out control components for at least a subset of the multiple tracks are first determined. The subset of the multiple tracks being boundary tracks of established zones of a disc. Data representative of the radially-dependent repeatable run-out control components for the subset of the multiple tracks is then stored in a table. The stored data representative of the radially-dependent repeatable run-out control components is utilized to interpolate or extrapolate the radially-dependent repeatable run-out control components for tracks within a zone or outside of the zones for which data is known.