Earth Mean Ecliptic and Equinox

The Earth Mean Ecliptic and Equinox of Date frame is defined as follows: - +Z axis is aligned with the north-pointing vector normal to the mean orbital plane of the Earth; - +X axis points along the ``mean equinox'', which is defined as the intersection of the Earth's mean orbital plane with the Earth's mean equatorial plane. It is aligned with the cross product of the north-pointing vectors normal to the Earth's mean equator and mean orbit plane of date; - +Y axis is the cross product of the Z and X axes and completes the right-handed frame; - the origin of this frame is the Earth's center of mass. The mathematical model used to obtain the orientation of the Earth's mean equator and equinox of date frame is the 1976 IAU precession model, built into SPICE. The mathematical model used to obtain the mean orbital plane of the Earth is the 1980 IAU obliquity model, also built into SPICE. The base frame for the 1976 IAU precession model is J2000.

http://www.voparis-ns.obspm.fr/rdf/ihdea/treps-coordinate-system-names#ECLIPDATE

The Earth Mean Ecliptic and Equinox of Date frame is defined as follows: - +Z axis is aligned with the north-pointing vector normal to the mean orbital plane of the Earth; - +X axis points along the ``mean equinox'', which is defined as the intersection of the Earth's mean orbital plane with the Earth's mean equatorial plane. It is aligned with the cross product of the north-pointing vectors normal to the Earth's mean equator and mean orbit plane of date; - +Y axis is the cross product of the Z and X axes and completes the right-handed frame; - the origin of this frame is the Earth's center of mass. The mathematical model used to obtain the orientation of the Earth's mean equator and equinox of date frame is the 1976 IAU precession model, built into SPICE. The mathematical model used to obtain the mean orbital plane of the Earth is the 1980 IAU obliquity model, also built into SPICE. The base frame for the 1976 IAU precession model is J2000.

Earth Mean Ecliptic and Equinox

ECLIPDATE

Earth Mean Ecliptic and Equinox

http://www.w3.org/2002/07/owl#Thing