Method for Measuring the Signal-To-Noise Ratio of Disk File Data Fields
Original Publication Date: 1988-May-01
Included in the Prior Art Database: 2005-Feb-15
Signal-to-noise (S/N) measurements on disk file data have normally been possible only as a ratio of continuous signal to an erased surface, due to limitations of test instrument response frequency. Preparation of a disk for tests required removal to a special rig, erasure of normal working pulses such as data, marks, ID's and servo patterns for the laboratory conditions of test. This article describes a method of signal-to-noise analysis under a functional environment, with varying data patterns, without removing the disk from its file and using normal manufacturing input and output connections. S/N is measured at the data peaks with data selected for analysis down to one bit. Accuracies are achieved of N 1 dB at 40 dB with only 8-bit conversion codes.