A method is disclosed for determining position information of a
transducer. At least a first code and a second code are chosen. The first
code has different characteristics than the second code. User data
written to a first sub-track is encoded with the first code and user data
written to a second sub-track is encoded with the second code. The first
code read from the first sub-track is obtained and the second code read
from the second sub-track is obtained. Position information of the
transducer is extracted from the obtained characteristics of the first
code and the obtained characteristics of the second code.