A position sensing and navigation system for use in navigating a medical device within a body of a patient, comprising: an impedance-based localization system having: a signal generator configured to continously and simultaneously apply each one of a plurality of drive signals across a corresponding one of a plurality of pairs of patch electrodes to create an electric field, wherein the drive signals each have a unique frequency that is a harmonic of a common base frequency; a demodulator configured to synchronously demodulate a composite response signal of at least one electrode of a medical device, disposed in the electric field, for the plurality of drive signals and output a demodulated data stream (172, 174); and a filter configured to receive the demodulated data stream (172, 174) and output impedance-based values proportional to the location of the electrode for each unique frequency; a magnetic field-based localization system having: a magnetic field generator for generating a magnetic field for use in acquiring a magnetic response from at least one magnetic sensor of the medical device disposed in the magnetic field; and a controller configured to pause input of the demodulated data stream into the filter during operation of the magnetic field generator for a time period that is an integer multiple of a common base period corresponding to the common base frequency an impedance-based localization system having: a signal generator configured to continously and simultaneously apply each one of a plurality of drive signals across a corresponding one of a plurality of pairs of patch electrodes to create an electric field, wherein the drive signals each have a unique frequency that is a harmonic of a common base frequency; a demodulator configured to synchronously demodulate a composite response signal of at least one electrode of a medical device, disposed in the electric field, for the plurality of drive signals and output a demodulated data stream (172, 174); and a filter configured to receive the demodulated data stream (172, 174) and output impedance-based values proportional to the location of the electrode for each unique frequency; a signal generator configured to continously and simultaneously apply each one of a plurality of drive signals across a corresponding one of a plurality of pairs of patch electrodes to create an electric field, wherein the drive signals each have a unique frequency that is a harmonic of a common base frequency; a demodulator configured to synchronously demodulate a composite response signal of at least one electrode of a medical device, disposed in the electric field, for the plurality of drive signals and output a demodulated data stream (172, 174); and a filter configured to receive the demodulated data stream (172, 174) and output impedance-based values proportional to the location of the electrode for each unique frequency; a magnetic field-based localization system having: a magnetic field generator for generating a magnetic field for use in acquiring a magnetic response from at least one magnetic sensor of the medical device disposed in the magnetic field; and a controller configured to pause input of the demodulated data stream into the filter during operation of the magnetic field generator for a time period that is an integer multiple of a common base period corresponding to the common base frequency a magnetic field generator for generating a magnetic field for use in acquiring a magnetic response from at least one magnetic sensor of the medical device disposed in the magnetic field; and a controller configured to pause input of the demodulated data stream into the filter during operation of the magnetic field generator for a time period that is an integer multiple of a common base period corresponding to the common base frequency