Patent ID: 7990644

Claim:
A method to decode linear position (“LPOS”) information encoded in a sequential information storage medium, comprising the steps of: detecting a plurality of sequential first LPOS servo patterns encoded in a first servo band using a first servo sensor in communication with a first servo channel; detecting a plurality of sequential first LPOS servo patterns encoded in a second servo band using a second servo sensor in communication with a second servo channel; when a data bit is detected in said first servo band, and a corresponding data bit is detected in said second servo band, pairing said data bit detected in said first servo band with said corresponding data bit detected in said second servo band and adding either said data bit detected in said first servo band or said corresponding data bit detected in said second servo band, to an LPOS word; when a data bit is detected in said first servo band, but a corresponding data bit is not detected in said second servo band, adding said data bit detected in said first servo band to said LPOS word; detecting an (i)th first servo signal encoded in said first servo band, wherein said (i)th servo signal encodes a value for an (i)th LPOS bit index, wherein (i) is greater than or equal to 1; setting an (i)th first LPOS bit index valid flag; calculating an (i)th second servo time interval; determining if an (i)th second servo signal encoded in said second servo band was detected within said (i)th second servo time interval; operative if an (i)th second servo channel signal was not detected within said second servo time interval, setting an (i)th second LPOS bit index invalid flag.