A bit-patterned magnetic media (BPM) includes with respect to each data track a first sub-track and a second sub-track, each sub-track comprised of a plurality of bit-islands. A transducer head placed over a data track generates a readback signal. Channel response circuitry demodulates the readback signal and detects fine positioning information based on a comparison of a readback signal generated in response to the first sub-track and a readback signal generated in response to the second sub-track.