1. A method for registering a three-dimensional model of a body volume to a real-time indication of a sensor position comprising: collecting reference data on a body volume; creating a three-dimensional model of said body volume; inserting a sensor into a body lumen and recording location data from said sensor; processing said location data to form a three-dimensional shape corresponding to space within said lumen; comparing said three-dimensional shape to said three dimensional model to establish at least an initial registration between said three-dimensional model and said real-time indication of a sensor position.