The right ascension of ascending node is the angular distance between the ascending node and the vernal equinox of the satellite orbit. The so-called ascending node is the intersection point with the equatorial plane of the earth when the satellite moves from south to north. Conversely, another intersection of the orbital plane and the equatorial plane is called the descending node. The equinox is the intersection of the ecliptic plane and the equatorial plane on the celestial sphere.
