afw tables persisted as FITS would be easier to read with standard tools such as TOPCAT if we could save angular fields in "nice" units, e.g. position in degrees and proper motion in milliarcseconds/year.
It would also be helpful to make numpy arrays and astropy table views of angular fields use quantities (or if that's too difficult, then at least use the units specified for persistence).
Jim Bosch has proposed an implementation in DM-15174. This RFC is to adopt that implementation, using his first (favored) choice for handling numpy arrays and astropy table views: use astropy quantities.
In that ticket he notes one issue with that approach: the schema will report the "nice" units but the data will be an astropy quantity in radians. I propose we just live with that, but Jim Bosch privately suggested another alternative that I will note here: make the desired persistence units for an angular field a new parameter that is only used by the persistence framework; getUnits() will always return "rad", matching the astropy quantity.