Patent ID: 6493573
Filing Date: 2002-12-10
Classification: A61B

Abstract:
A correction system for determining an effect of at least one interfering object on a field sensor within a navigational domain, the system comprising:a first transmitter configured to project, into said navigational domain, field energy in a first waveform at a first frequency sufficient to induce a first desired signal value in said field sensor from said first transmitter and a first disturbance signal value in said field sensor from said at least one interfering object; a second transmitter configured to project, into said navigational domain, field energy in a second waveform at a second frequency sufficient to induce a second desired signal value in said field sensor from said second transmitter and a second disturbance signal value in said field sensor from said at least one interfering object; and, a signal processor configured to receive said first desired and disturbance signal values and said second desired and disturbance signal values and to determine influences of said at least one interfering object on said field sensor from said first and second disturbance signal values, to thereby permit a substantially precise location of said field sensor to be determined despite the presence of said at least one interfering object.