A method is disclosed for determining fundamental-frequency repeatable
runout (1FRRO) coefficients in a disk drive. The disk drive includes a
transducer head, a rotating magnetic disk having a plurality of
concentric data tracks defined by embedded servo wedges that provide
position information, and an actuator coupled to the head. In the method,
the head is caused to move in a substantially constant velocity motion
across a selected portion of the tracks of the rotating magnetic disk in
response to a control signal. The position information is read from the
embedded servo wedges as the head moves across of the selected portion of
the tracks. The 1FRRO coefficients are determined based on the position
information read as the head moved in a substantially constant velocity
motion across the selected portion of the tracks.