Patent ID: 8837263

Claim:
A hard disk drive comprising: a processor; memory connected to the processor, configured to store a reference sync-mark and a reference distance threshold; a data storage element connected to the processor; and computer executable program code configured to execute on the processor, wherein the computer executable program code is configured to: read a data stream from the data storage element; detect a first sync-mark in the data stream, the first sync-mark having one or more characteristics substantially similar to one or more characteristics of the reference sync-mark based on the reference distance threshold; detect a second sync-mark in the data stream, the second sync-mark having one or more characteristics substantially similar to one or more characteristics of the reference sync-mark based on the reference distance threshold; update the reference distance threshold; determine a Euclidean distance associated with the first sync-mark; determine a Euclidean distance associated with the second sync-mark; determine an average Euclidean distance based on the first sync-mark and the second sync-mark; determine an estimated early detection rate associated with a new distance threshold based on the average Euclidean distance; and determine an estimated miss detection rate associated with the new distance threshold based on the average Euclidean distance.