However, an IntraMap is intended for use within a single program or a private suite of software, where all programs have access to the same coordinate transformation functions (i.e. can be linked against them). IntraMaps should not normally be stored in datasets which may be exported for processing by other software, since that software will not have the necessary transformation functions available, resulting in an error.
You must register any coordinate transformation functions to be used using astIntraReg before creating an IntraMap.
AST A Library for Handling World Coordinate Systems in Astronomy