US 11,756,581 B1
Position and risk reconstruction in shingled magnetic recording data storage devices
Weldon M. Hanson, Rochester, MN (US); Alain Chahwan, Irvine, CA (US); and Niranjay Ravindran, Rochester, MN (US)
Assigned to Western Digital Technologies, Inc., San Jose, CA (US)
Filed by Western Digital Technologies, Inc., San Jose, CA (US)
Filed on Mar. 24, 2022, as Appl. No. 17/703,318.
Int. Cl. G11B 5/596 (2006.01); G11B 5/56 (2006.01); G11B 5/012 (2006.01)
CPC G11B 5/59688 (2013.01) [G11B 5/012 (2013.01); G11B 5/59627 (2013.01)] 22 Claims
OG exemplary drawing
 
1. A data storage device comprising:
a disk comprising a plurality of data tracks, including a data track N and a data track N−1;
a head actuated over the disk; and
one or more processing devices configured to:
measure one or more signal to noise ratio (SNR) metrics for corresponding sectors of at least one of the data track N and the data track N−1, wherein the measuring is based at least in part on reading one or more of the data track N and the data track N−1 using one or more read offsets;
estimate a position of at least one of the data track N and the data track N−1, wherein estimating the position is based at least in part on measuring the one or more SNR metrics; and
reconstruct:
one or more risk values for at least a portion of the data track N−1, based on the one or more SNR metrics for the data track N−1, and wherein the one or more risk values correspond to a write abort threshold to abort writing data to the data track N, and
a position error signal (PES) for at least one of the data track N−1 and the data track N based on the corresponding estimated positions.