Glossary
free core nutation (FCN)
free core nutation (FCN)
free mode in the motion of the Earth's rotation axis with respect to the Earth, due to non-alignment of the rotation axis of the inner core with respect to the mantle; the period is retrograde diurnal in the terrestrial frame and prograde long-period in the celestial frame.
Source: IERS Technical Note 36: Glossary (not accessible) [PDF, 244 KB] of the IERS Conventions (2010)
fundamental arguments
fundamental arguments
a set of mathematical expressions for angles used to describe orbital parameters of solar system objects used in precession/nutation models.
Source: IERS Technical Note 36: Glossary (not accessible) [PDF, 244 KB] of the IERS Conventions (2010)
