- We look at multiple-track detection for magnetic recording systems that use array heads to write and read over multiple tracks simultaneously. The recording channel is modeled as having intersymbol interference (ISI) in the axial direction, and intertrack interference (ITI) in the radial direction. Optimum multihead and single-head detectors are derived and analyzed in terms of error-probability performance for various levels of intertrack interference. Among other results, it is seen that for a range of ITI levels, codes designed to increase distance in single-head systems can provide the same coding gains for multihead systems. 1998 IEEE.