Of the
initial wide track that is written, only a narrow portion along
one edge of the track remains after the track adjacent to it is
written. The write head needs to have a side-shield only along
that edge. For 2-D readback, powerful signal processing can
be applied that takes advantage of knowing the waveforms on
the adjacent tracks. A highly accurate track following system
will also be applied to deliver the required spatial resolution.
If the writing process and the readback process both have very
high resolution and very low noise or uncertainty, then TDMR
theoretically can approach an information capacity of one bit
on each grain.