meas_mosaic writes its WCS as FITS header with no attached image, which requires loading code to use the following pattern:
instead of simply
Using a header-only format also limits us to FITS-standard WCS mappings.
Because Wcs inherits from afw::table::io::Persistable it already has writeFits and readFits methods that utilize our FITS binary table format, which will be able to save more complex WCS solutions. It's also compatible (or will be soon, on
DM-10728) with the "FitsCatalogStorage" butler storage type, so we should be able to fix this by:
- Redefining "wcs" to be a "FitsCatalogStorage" dataset, instead of a "FitsStorage" exposure in all mappers;
- modifying meas_mosaic (and possibly jointcal, if needed) to use butler.put directly.
- modifying any code that consumes the wcs dataset to use butler.get directly.
In addition, this issue should include creating a simple command-line script that can be used to convert a data repository from the old format to the new one.