| 摘要 |
PROBLEM TO BE SOLVED: To provide methods and apparatus for improved physical re-read operations in a hard disk drive.SOLUTION: The disclosed methods and apparatus selectively retain data in a hard disk drive. A signal is read in an iterative read channel by: assigning a reliability metric to each of a plurality of segments in a read signal; repeating the assigning step for a plurality of read operations; and selectively retaining the segments on the basis of the assigned reliability metric. The read signal can be obtained by positioning a transducer over a storage medium. The reliability metric may be based on soft bit decisions, log likelihood ratios or a noise estimation of a given segment. |
