Methods for characterizing the replay pulse asymmetry for a digital magnetic recording channel

Two methods are examined for characterizing the asymmetric replay pulse from the digital magnetic recording channel. A time domain method based on the Taylor series expansion of a mixed longitudinal/perpendicular pulse model is used to obtain simple relationships between the replay pulse asymmetry and model parameters. A frequency domain method based on modelling the channel phase is used to characterize a simple longitudinal pulse model with linear displacement of the transition through the recording depth