Reference Files
===============

WCS Reference files are in the Advanced Scientific Data Format (ASDF).
The best way to create the file is to programmatically create the model and then save it to a file.
A tutorial on creating reference files in ASDF format is available at:

https://github.com/spacetelescope/jwreftools/blob/master/docs/notebooks/referece_files_asdf.ipynb

Transforms are 0-based. The forward direction is from detector to sky.

Reference file types used by ``assign_wcs``
-------------------------------------------

Currently none