A system for determining a position of a medical device within a body, comprising: an electronic control unit configured to: receive a position signal from each of a plurality of position sensors of a first type disposed on the medical device and from at least one position sensor of a second type disposed on the medical device; apply a noise reduction filter to each of said position signals to obtain filtered estimated positions for each of said plurality of position sensors of said first type and said at least one position sensor of said second type; compute a spline connecting said plurality of position sensors of said first type responsive to said filtered estimated positions for said plurality of positions sensors of said first type; estimate a spline position for said at least one position sensor of said second type along said spline by using a known positional relationship of the position sensors to each other; generate a first map between said spline position and said filtered estimated position of said at least one position sensor of said second type; generate a second map between said spline position and an unfiltered estimated position of said at least one position sensor of said second type; generate a composite map by combining said first and second maps; and, determine an actual position for one of said plurality of position sensors of said first type responsive to said composite map and said filtered estimated position for said one position sensor of said first type. an electronic control unit configured to: receive a position signal from each of a plurality of position sensors of a first type disposed on the medical device and from at least one position sensor of a second type disposed on the medical device; apply a noise reduction filter to each of said position signals to obtain filtered estimated positions for each of said plurality of position sensors of said first type and said at least one position sensor of said second type; compute a spline connecting said plurality of position sensors of said first type responsive to said filtered estimated positions for said plurality of positions sensors of said first type; estimate a spline position for said at least one position sensor of said second type along said spline by using a known positional relationship of the position sensors to each other; generate a first map between said spline position and said filtered estimated position of said at least one position sensor of said second type; generate a second map between said spline position and an unfiltered estimated position of said at least one position sensor of said second type; generate a composite map by combining said first and second maps; and, determine an actual position for one of said plurality of position sensors of said first type responsive to said composite map and said filtered estimated position for said one position sensor of said first type. receive a position signal from each of a plurality of position sensors of a first type disposed on the medical device and from at least one position sensor of a second type disposed on the medical device; apply a noise reduction filter to each of said position signals to obtain filtered estimated positions for each of said plurality of position sensors of said first type and said at least one position sensor of said second type; compute a spline connecting said plurality of position sensors of said first type responsive to said filtered estimated positions for said plurality of positions sensors of said first type; estimate a spline position for said at least one position sensor of said second type along said spline by using a known positional relationship of the position sensors to each other; generate a first map between said spline position and said filtered estimated position of said at least one position sensor of said second type; generate a second map between said spline position and an unfiltered estimated position of said at least one position sensor of said second type; generate a composite map by combining said first and second maps; and, determine an actual position for one of said plurality of position sensors of said first type responsive to said composite map and said filtered estimated position for said one position sensor of said first type.