A system for determining a position of a catheter is provided. An electrode is on a catheter. A plurality of reference electrodes are provided. Each of the plurality of reference electrodes are configured to transmit or receive a signal to or from the electrode, respectively. A processor is operable to determine a position of the catheter as a function of an electrical characteristic based on the signals. The plurality of reference electrodes are not positioned on or in a body surface along three mutually orthogonal axes.
