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 magnetic recording device allows the in 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 heads positioned adjoining to a prerecorded track. In this paper, the theory is derived for such a noninvasive measurement and the required measurement conditions are discussed. The uncertainty in the measurement due to the noise in the readback signal is also presented.