Patent ID: 6344743
Filing Date: 2002-02-05
Classification: G01R

Abstract:
A system for determining the distribution of a magnetic field of interest, said system comprising:a sensor which is characterized by a sensor length, said sensor being capable of measuring a magnetic field amplitude value over said sensor length, said magnetic field amplitude value being equivalent to an integral of the overall magnetic field which said sensor senses over said length; means for generating alternating current at at least two frequencies; and means for conducting said generated alternating current so as to establish, in association with each of said at least two frequencies, a standing wave magnetic field along said sensor length, each said established standing wave magnetic field being characterized by a corresponding spatial distribution representing a different whole number of harmonic cycles in relation to said sensor length; wherein, in association with each of said at least two frequencies, said measured magnetic field amplitude corresponding to said overall magnetic field which said sensor senses represents a product combination of said magnetic field of interest and the corresponding said established standing wave magnetic field, said sensor thereby measuring a spatial Fourier coefficient corresponding to a component of said magnetic field of interest, said component corresponding to said spatial distribution characterizing the corresponding said established standing wave magnetic field; and wherein at least two said measured spatial Fourier coefficients are usable for evaluating a Fourier series, said evaluating a Fourier series thereby being based on at least two said components of said magnetic field of interest so that values may be computed which are indicative of said distribution of said magnetic field of interest coefficient.