Premium
Determination of the external geomagnetic field from intensity measurements
Author(s) -
Backus George E.
Publication year - 1974
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl001i001p00021
Subject(s) - earth's magnetic field , physics , intensity (physics) , computation , bounded function , magnetic field , field (mathematics) , field intensity , sign (mathematics) , mathematical analysis , mathematics , optics , nuclear magnetic resonance , pure mathematics , quantum mechanics , algorithm
Suppose a closed, bounded region M contains all the sources (currents and magnets) of the geomagnetic field B , and M′ , the rest of space, is connected (any two points in M′ can be joined by a smooth curve). Suppose that the total intensity of B is known in some open region contained entirely inside M′ . Then the vector field B is uniquely determined up to sign in all of M′ . The result is less trivial than it seems, being false in two dimensions. Since the method of proof involves analytic continuation, computations based on it will probably be numerically unstable.