This attribute holds the longitude value, in radians, to be returned when a Cartesian position corresponding to either the north or south pole is transformed into spherical coordinates. The default value is zero.

Note, the value of this attribute may changed only if the SphMap has no more than one reference. That is, an error is reported if the SphMap has been cloned, either by including it within another object such as a CmpMap or FrameSet or by calling the AST_CLONE function.

SphMap