1. A method for processing of multi-dimensional read back signal to reduce Inter Symbol Interference (ISI) and noise, said method comprising the step of: equalizing the read back signal using a linear equalizer that adapts to varying channel conditions; and designing a Partial Response (PR) target for signal detection based on Partial Response Maximum Likelihood (PRML) and the equalizer output, wherein the equalizer and the PR target are jointly adapted; wherein the step of equalizing enables handling of channel conditions accounting for one or more time varying factors selected from any or a combination of wear and tear, media and temperature variations.