A localization system, comprising: at least one catheter configured for delivery of one or more biopotential electrodes in a 3D array of known shape to a body cavity defined by surrounding tissue; a patient interface module comprising a plurality of localization electrodes (56, 58) configured for fixed orientation relative to the body, the localization electrodes (56, 58) including one or more pairs of localization electrodes, wherein each pair of localization electrodes defines an axis of a coordinate system; further comprising: a cardiac information console comprising: a localization processor configured to process localization signals from the localization electrodes (56, 58); a localization driving circuity (28,29) configured to process the signals from the localization processor to generate waveforms for localization, driving each pair of localization electrodes to establish each axis of the coordinate system, wherein the cardiac information console is configured to: process biopotential signals received from the one or more biopotential electrodes to orient the 3D electrode array of biopotential electrodes within the coordinate system, and rotate and scale the coordinate system to adjust and correct the orientation and relative sizes of the axes for a more accurate localization representation of the biopotential electrodes; wherein the rotation and scaling of the coordinate system is based on a comparing of an expected or known shape of the 3D electrode array and relative dimensions with a representation of the 3D electrode array in the established coordinate system; and the cardiac information console further comprises: an ADC coupled to outputs of the biopotential signal path and the localization signal path; an IQ demodulator, for each electrode, coupled to the output of the ADC and configured to separate a magnitude and a phase of a received data signal; a narrow band IIR filter coupled to the IQ demodulator; and a time filter coupled to the IIR filter, and configured to selectively filter out portions of data on a time basis. at least one catheter configured for delivery of one or more biopotential electrodes in a 3D array of known shape to a body cavity defined by surrounding tissue; a patient interface module comprising a plurality of localization electrodes (56, 58) configured for fixed orientation relative to the body, the localization electrodes (56, 58) including one or more pairs of localization electrodes, wherein each pair of localization electrodes defines an axis of a coordinate system; further comprising: a cardiac information console comprising: a localization processor configured to process localization signals from the localization electrodes (56, 58); a localization driving circuity (28,29) configured to process the signals from the localization processor to generate waveforms for localization, driving each pair of localization electrodes to establish each axis of the coordinate system, wherein the cardiac information console is configured to: process biopotential signals received from the one or more biopotential electrodes to orient the 3D electrode array of biopotential electrodes within the coordinate system, and rotate and scale the coordinate system to adjust and correct the orientation and relative sizes of the axes for a more accurate localization representation of the biopotential electrodes; a localization processor configured to process localization signals from the localization electrodes (56, 58); a localization driving circuity (28,29) configured to process the signals from the localization processor to generate waveforms for localization, driving each pair of localization electrodes to establish each axis of the coordinate system, wherein the cardiac information console is configured to: process biopotential signals received from the one or more biopotential electrodes to orient the 3D electrode array of biopotential electrodes within the coordinate system, and rotate and scale the coordinate system to adjust and correct the orientation and relative sizes of the axes for a more accurate localization representation of the biopotential electrodes; process biopotential signals received from the one or more biopotential electrodes to orient the 3D electrode array of biopotential electrodes within the coordinate system, and rotate and scale the coordinate system to adjust and correct the orientation and relative sizes of the axes for a more accurate localization representation of the biopotential electrodes; wherein the rotation and scaling of the coordinate system is based on a comparing of an expected or known shape of the 3D electrode array and relative dimensions with a representation of the 3D electrode array in the established coordinate system; and the cardiac information console further comprises: an ADC coupled to outputs of the biopotential signal path and the localization signal path; an IQ demodulator, for each electrode, coupled to the output of the ADC and configured to separate a magnitude and a phase of a received data signal; a narrow band IIR filter coupled to the IQ demodulator; and a time filter coupled to the IIR filter, and configured to selectively filter out portions of data on a time basis. an ADC coupled to outputs of the biopotential signal path and the localization signal path; an IQ demodulator, for each electrode, coupled to the output of the ADC and configured to separate a magnitude and a phase of a received data signal; a narrow band IIR filter coupled to the IQ demodulator; and a time filter coupled to the IIR filter, and configured to selectively filter out portions of data on a time basis.