Patent ID: 8280189

Claim:
A method for tracking a position of an object, comprising: using a field sensor, which comprises one or more field sensing elements associated with the object, and determining redundant field measurements using the one or more field sensing elements to measure redundant field strengths of magnetic fields generated by two or more field generators so as to provide redundant location information, wherein a measurement of at least one of the field strengths is subject to a distortion; identifying, responsively to the measured field strengths, at least one distortion-contributing system element, which is selected from a group consisting of the one or more field sensing elements and of the two or more field generators; and determining location coordinates of the object relative to the two or more field generators responsively to the measured field strengths while disregarding field measurements associated with the distortion-contributing system element by applying to the redundant field measurements a coordinate correcting function according to a plurality of sub-volumes of the working volume that exploits the redundant location information so as to reduce an impact of the distortion on the location coordinates.