GWCS is a package for managing the World Coordinate System (WCS) of astronomical data. It takes a general approach to the problem of expressing arbitrary transformations by supporting a data model which includes the entire transformation pipeline from input coordinates (detector by default) to world coordinates (standard celestial coordinates or physical quantities). Transformations from the detector to a standard coordinate system are combined in a way which allows for easy manipulation of individual components. The framework handles discontinuous models (e.g. IFU data) and allows quantities that affect transforms to be treated as input coordinates (e.g. spectral order). It provides flexibility by allowing access to intermediate coordinate frames. The WCS object is serialized to a file using the language independent Advanced Scientific Data Format (ASDF).Alternatively the ASDF object can be encapsulated in a FITS extension. The package is written in python and is based on astropy. It is easy to extend by adding new models and coordinate systems.
Link to PDF (may not be available yet): O12-3.pdf