Methods and systems for improved navigation

Systems and methods for navigation are presented. First and second response signals received from at least one magnetic sensor operatively coupled to a target device in response to a magnetic field are measured at reference and reversed sensitivity while an alignment of magnetic domains corresponding to the magnetic sensor remains unchanged. A useful portion of the first response signal is determined by eliminating common-mode noise from the first response signal based on a difference between the first and second response signals. Alternatively, a bias signal having a desired bias frequency is applied to shift a signal frequency of a response signal of a magnetoresistance sensor that includes common-mode noise. A useful portion of the response signal is determined by measuring the response signal at a shifted frequency that is a sum of the signal and bias frequencies. A position of the subject is then determined based on the useful portion.