TechnicalRAAN
Right Ascension of the Ascending Node
The orbital element specifying where an orbit's ascending node lies relative to a fixed reference direction, orienting the orbital plane in space.
RAAN fixes the orientation of the orbital plane around the Earth's axis by giving the angle, measured in the equatorial plane, from a reference direction to the ascending node — the point where the satellite crosses the equator heading north.
It is essential for defining a constellation's geometry and for sun-synchronous orbits, where the RAAN is managed so the orbit precesses at the rate needed to keep a constant local solar time.