A position sensing and map generating unit, comprising: a set of axis electrodes configured to inject a current into a volume; a mapping instrument having a first position element comprising at least two electrodes and operable to be located in the volume and sense a voltage or bioimpedance due to the injected current at a plurality of locations within the volume; a position determination processor operable to determine a position of the mapping instrument at least with the first position element to generate map data points related to each location of the plurality of locations; a display device operable to display a map based at least on the map data points determined from positioning of the mapping instrument; a display processor operable to augment the map on the display device, wherein the display processor is operable to: determine a position of the first position element that is positioned to sense the voltage or the bioimpedance formed in the volume; a physiological measuring device; an introducer operable to be located with the position determination processor; a reference electrode at a fixed position on a surface of the volume and a location of the reference electrode is determined with the position determination processor; a procedure instrument (120, 140) with a second position element operable to be located relative to the map; wherein a map of a volume is displayed with the display device for visualization by a user based solely on determined positions of one or more of the position elements; and wherein a location of the procedure instrument is displayed with the display device relative to the displayed map of the volume. a set of axis electrodes configured to inject a current into a volume; a mapping instrument having a first position element comprising at least two electrodes and operable to be located in the volume and sense a voltage or bioimpedance due to the injected current at a plurality of locations within the volume; a position determination processor operable to determine a position of the mapping instrument at least with the first position element to generate map data points related to each location of the plurality of locations; a mapping instrument having a first position element comprising at least two electrodes and operable to be located in the volume and sense a voltage or bioimpedance due to the injected current at a plurality of locations within the volume; a position determination processor operable to determine a position of the mapping instrument at least with the first position element to generate map data points related to each location of the plurality of locations; a display device operable to display a map based at least on the map data points determined from positioning of the mapping instrument; a display processor operable to augment the map on the display device, wherein the display processor is operable to: determine a position of the first position element that is positioned to sense the voltage or the bioimpedance formed in the volume; a physiological measuring device; an introducer operable to be located with the position determination processor; a reference electrode at a fixed position on a surface of the volume and a location of the reference electrode is determined with the position determination processor; a procedure instrument (120, 140) with a second position element operable to be located relative to the map; wherein a map of a volume is displayed with the display device for visualization by a user based solely on determined positions of one or more of the position elements; and wherein a location of the procedure instrument is displayed with the display device relative to the displayed map of the volume. a procedure instrument (120, 140) with a second position element operable to be located relative to the map; wherein a map of a volume is displayed with the display device for visualization by a user based solely on determined positions of one or more of the position elements; and wherein a location of the procedure instrument is displayed with the display device relative to the displayed map of the volume.