The magnetic recording channel: noise, distortion and overwrite

It is noted that the noise, distortion, and interference which are present in a digital magnetic recording channel are unique. They depend on the type of magnetic recording medium and are not simply additive. The authors examine the properties of digital recording on rigid disks with thin metallic recording films and inductive read/write heads flying with a finite height above the recording surface; only longitudinally magnetized films are discussed. The channel is described with a zero´th-order model of saturated recording. The authors then describe then phenomena which cause it to depart from this simple model: distortion, noise, overwrite, and crosstalk. Physical origins of these phenomena are described, and techniques for measuring noise and distortion are discussed