📘 Definition
The Right Ascension of the Ascending Node (RAAN, or Ω) defines where the satellite's orbital plane intersects the equatorial plane on its way north. It is measured as an angle from the vernal equinox direction (0° to 360°). Together with inclination, RAAN completely specifies the orientation of the orbital plane in space. RAAN precesses (changes gradually) due to Earth's oblate shape (the J2 perturbation), which is actually exploited to maintain sun-synchronous orbits.
0°–360°
Range
Vernal equinox (♈)
Reference
J2 perturbation
Drift Cause
#3 of 6
Keplerian Element