The WCS is validated when an object is read in or written to a file. However, this happens transparently to the end user and knowing the details of the validation machinery is not necessary to use or construct a WCS object.
GWCS uses the
Advanced Scientific Data Format
(ASDF) to serialize and deserialize GWCS objects (including transformations
and frames) and to provide validation that the serialization is correct.
ASDF makes use of abstract data type definitions called
The serialization and deserialization happens in classes, referred to as
converters defined in
gwcs.converters.* modules. Most of the schemas
available for the WCS object, coordinate frames and some WCS specific transforms
live in the
Packages using GWCS may create their own transforms and schemas and register
them as an
Asdf Extension. If those are of general use, it is recommended
they be included in asdf-astropy.