Translation between FITS keywords and ASDF Tree

[tiagopereira]

The FITS standard devotes most of its pages to the definition of header keywords. The ASDF standard, on the other hand, provides very little information on conventions to write metadata in the tree for astronomical files. While I appreciate the freedom of ASDF, I think some guidance would be really helpful to avoid people writing incompatible metadata.

What I was looking for was, for example, to find the standard way to write metadata such as DATE-OBS, TELESCOP, EXPTIME and so on. I've read the ASDF paper and the standard, and they do explain some of the new ways of representing metadata, but surprisingly few and with no recommended conventions. Is it possible to provide more complete examples?

I'm trying to categorise and repackage some data we have internally, and would love to use ASDF (at least for the metadata) to keep it future-proof. It would be nice to be able to use standard formulations, to avoid having to rewrite everything when a convention appears.