Magnetometer systems, and associated methods, are provided including a first magnetometer (22a,24a) adapted to generate an external magnetic field having a characteristic that is varied over time, and a second magnetometer (22b,24b) adapted to receive the magnetic field and generate at least one magnetometer signal representing a change in the magnetic field. In one embodiment, the magnetic field characteristic includes the frequency of the generated magnetic field. In another embodiment, the magnetic field characteristic includes the frequency period of the magnetic field.
