Patent ID: 7504825

Claim:
A method for compensating in a space volume for a magnetic noise field outside the space volume, the method comprising: determining a strength of the magnetic noise field outside the space volume, wherein determining the strength of the magnetic noise field outside the space volume includes determining a component of the noise field outside the space volume along a direction which is parallel or has a fixed orientation relative to a selected direction in the space volume along which a compensation is to be carried out; defining a correlation between the noise field outside the space volume and a corresponding noise field inside the space volume, or calculating the noise field inside the space volume on the basis of the determined strength of the magnetic noise field outside the space volume; determining a noise field component inside the space volume along the selected direction; compensating for the magnetic noise field outside the space volume by generating a compensation noise field component along the selected direction; and wherein the compensation noise field component inside the space volume along the selected direction is determined as a function of an angular position or of an angular displacement of the direction of compensation with respect to a direction of measurement of the magnetic noise field outside the space volume.