Typed cartesian coordinate templates.
Position< centers::Heliocentric, frames::EclipticMeanJ2000, U > EclipticMeanJ2000
Position< centers::Geocentric, frames::EclipticMeanJ2000, U > MoonGeocentric
Position< centers::Barycentric, frames::EclipticMeanJ2000, U > HelioBarycentric
Position< centers::Barycentric, frames::EclipticMeanJ2000, U > GeoBarycentric
A 3D Cartesian position, compile-time tagged by center, frame, unit.