A method and system for correcting tracking errors in an optical storage
medium having multiple tracks arranged in different layers of the optical
storage medium, directs a reading spot that is nominally focused on to a
track in the optical storage medium, and continually moves the reading
spot in axial and radial directions so as to receive a signal having an
amplitude which varies according to respective offsets from the track in
radial and axial directions. The received signal is used to determine a
direction of a respective offset from the track in radial and axial
directions, and a location of the reading spot is adjusted accordingly.
