Patent ID: 8810955

Claim:
A data storage system, comprising: a disk platter storing a plurality of periodic data sequences; a plurality of read heads located proximate to the disk platter; and at least one processor in communication with at least a first read head and a second read head of the plurality of read heads, the at least one processor being configured to: receive a first set of readback signals from the first read head and the second read head, the first set of readback signals being based upon a first periodic data sequence and a second periodic data sequence detected by the first read head and the second read head at a first fly height of the first read head and a first fly height of the second read head; receive a second set of readback signals from the first read head and the second read head, the second set of readback signals being based upon the first periodic data sequence and the second periodic data sequence detected by the first read head and the second read head at a second fly height of the first read head and a second fly height of the second read head; determine a difference between the first fly height of the first read head and the second fly height of the first read head and a difference between the first fly height of the second read head and the second fly height of the second read head by comparing the first set of readback signals and the second set of readback signals; and estimate a change in fly height for the plurality of read heads at least partially based upon a summation of the difference between the first fly height of the first read head and the second fly height of the first read head and the difference between the first fly height of the second read head and the second fly height of the second read head, wherein each of the difference values is multiplied by a fusion coefficient.