International Geomagnetic Reference Field
The International Geomagnetic Reference Field (IGRF) is a standard mathematical description of the Earth's main magnetic field. It is the product of a collaborative effort between magnetic field modellers and the institutes involved in collecting and disseminating magnetic field data from satellites and from observatories and surveys around the world.
Read more about International Geomagnetic Reference Field: Spherical Harmonics
Famous quotes containing the words reference and/or field:
“If we define a sign as an exact reference, it must include symbol because a symbol is an exact reference too. The difference seems to be that a sign is an exact reference to something definite and a symbol an exact reference to something indefinite.”
—William York Tindall (1903–1981)
“Love to chawnk green apples an’ go swimmin’ in the
lake.—
Hate to take the castor-ile they give for belly-ache!
‘Most all the time, the whole year round, there ain’t no flies on
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But jest ‘fore Christmas I’m as good as I kin be!”
—Eugene Field (1850–1895)