Array heads for estimating track misregistration

The authors examine the use of array heads for estimating the data and for providing servo information. A mathematical representation for array heads is developed, and a formula for the maximum likelihood estimate of the track misregistration is found. The case where the offtrack perturbation operator is dependent on the offtrack error is considered. This case requires a joint minimization of two branches of quadratic forms. Simulation results for a specific head configuration are given which validate the estimate and agree with the theoretical convergence rates. The estimate converges quickly enough for practical purposes in a real storage system