Head-medium clearance and lateral track registration of a recording head as measured from the readback signal

Electronic processing of the harmonic content of the readback signal of a m agnetic recording device allows the lit situ determination of the slider-to -medium mechanical clearance for heads positioned directly over prerecorded tracks and the determination of the lateral displacement variation for hea ds positioned adjoining to a prerecorded track, In this paper, the theory i s derived for such a noninvasive measurement and the required measurement c onditions are discussed. The uncertainty in the measurement due to the nois e in the readback signal is also presented.