Overwrite in thin media measured by the method of pseudorandom sequences

The method of pseudorandom sequence channel identification is applied to the measurement of bit shift due to overwrite in magnetic recording. The experimental results are compared to results of other overwrite measurement techniques. The proposed method has the advantage of simultaneously quantifying the bit shift due to overwrite and that due to other nonlinear effects. A simple magnetic model is proposed to explain the main features of the overwrite phenomenon. The bit shift is attributed to the interaction of the magnetic field produced by the head and the demagnetizing fields in the media produced during the write process