where is the longitude of the ascending node and is the argument of pericenter. is therefore a broken angle, measured in the reference plane from the zero point to the ascending node and then around the orbit.
Argument of Pericenter, Ascending Node, Line of Apsides, Longitude of the Ascending Node
References
Montenbruck, O. and Pfleger, T. Astronomy on the Personal Computer, 4th ed. Berlin: Springer-Verlag, p. 72, 2000.
