Longitude of the ascending node is the unit vector (0, 0, 1), which is the normal vector to the "xy" reference plane. For non-inclined orbits (with inclination equal to zero), Ω is undefined. For computation it is then, by convention, set equal to zero; that is, the ascending node is placed in the reference direction, which is equivalent to letting n point towards the positive "x"-axis. Longitude of the ascending node The longitude of the ascending node (☊ or Ω) is one of the orbital elements used to specify the orbit of an object in space. It is the angle from a reference direction, called
Cylindrical equal-area projection many named specializations such as Gall–Peters or Gall orthographic, Behrmann, and Lambert cylindrical equal-area). This divides north-south distances by a factor equal to the secant of the latitude, preserving area but heavily distorting shapes. Any particular cylindrical equal-area map has a pair of identical latitudes of opposite sign (or else the equator) at which the east–west scale matches the north–south scale. All cylindrical equal-area projections use the formula: where "λ" is the longitude, "λ" is the central meridian, "φ" is the latitude, and "φ" is the standard latitude, all expressed in radians. Some cartographers prefer to work in degrees, rather