signal correction is performed by determining an offset error based at least in part on a first portion of a signal within a first amplitude range . the offset error is associated with error due to offset in the signal . an signal error , associated with error due to offset and magneto - resistive asymmetry in the signal , is determined based at least in part on a second portion of the signal within a second amplitude range ; the second amplitude range does not overlap with the first amplitude range . an mra error is determined by removing the offset error from the signal error and the mra error is removed from the signal .