Composite data recovery procedure

A method of recovering data from one or more failed data sectors, the method comprising:

• estimating a reader offset position from a first or a second read attempt of the one or more failed data sectors at a current set of channel parameters and basing the estimated reader offset position on, at least in part, a position error signal generated during the first or second read attempt;
• replacing the current set of channel parameters with a new set of channel parameters selected from adaptive channel parameters or predetermined channel parameters;
• performing at least one read on the one or more failed data sectors at the estimated reader offset position and using the new set of channel parameters to obtain one or more samples;
• processing the one or more samples to obtain a processed sample;
• and
• performing iterative outer code recovery on the processed sample.

A method of recovering data from one or more failed data sectors, the method comprising:

• estimating a reader offset position from a first or a second read attempt of the one or more failed data sectors at a current set of channel parameters and basing the estimated reader offset position on, at least in part, a position error signal generated during the first or second read attempt;
• replacing the current set of channel parameters with a new set of channel parameters selected from adaptive channel parameters or predetermined channel parameters;
• performing multiple reads on the one or more failed data sectors at the estimated reader offset position and using the new set of channel parameters to obtain a plurality of samples;
• processing the plurality of samples to obtain a processed sample;
• and
• removing interference from the processed sample to obtain an updated processed sample, wherein the interference is derived from an adjacent track having one or more data sectors that are adjacent to the one or more failed data sectors.