Patent ID: 6757557
Filing Date: 2004-06-29
Classification: A61B,G01B,G01S,G01V,H01F

Abstract:
A method of determining a location and an orientation of a field sensor relative to a plurality of magnetic field sources of known location, the method comprising the steps of:1) energizing each field source and measuring a respective field generated by each field source at the field sensor; 2) for each field source, calculating, from the measurements of the field generated by the field source and an estimate of the orientation of the sensor, an estimate of the distance from that particular field source to the sensor; 3) utilizing the estimates of distance from step 2), and the known location of the field sources to calculate an estimate of the location of the sensor; 4) employing the estimated location of the sensor from step 3) and the measurements of the field at the sensor to calculate a new estimate of the orientation of the sensor; and 5) repeating steps 2) to 4) iteratively with step 2) employing the new estimate of sensor orientation from the preceding step 4), to improve the estimates of location and orientation of the sensor.