Since the last DrizzlePac Handbook release in 2012 (Gonzaga et al. 2012), many changes have been implemented in the DrizzlePac code. A revision of the DrizzlePac Handbook was undertaken by the ACS and WFC3 teams at STScI to provide an up to date resource for the user community and published in February 2021. The new 2.0 version represents an overall review and modernization of the handbook content with additions to address new features. Notably, ACS and WFC3 images retrieved after December 2019 now include improved absolute astrometry achieved by matching sources in HST images directly to the Gaia DR2 reference catalog, reducing astrometric errors to approximately 10 mas. The updated world coordinate system (WCS) solutions are populated in new headerlet extensions in calibrated images. Information is provided to familiarize users with the structure of the new FITS images and demonstrate how the primary WCS may be updated to any other preferred solution.
The new DrizzlePac Handbook version also replaces the static text examples with DrizzlePac Jupyter notebooks, which contain explanations and Python coding for various drizzle use cases. A synopsis of each notebook is provided so that the user can determine which notebook will be helpful for their science goals.
Another exciting change is that all of this content is now hosted on the HST Document (HDox) website in the same space as the HST instrument handbooks for convenience and ease of use. The online platform is searchable, integrated with the HST help desk portal, and allows for changes as necessary so the handbook remains updated and relevant to users. Please take a look at the new DrizzlePac Handbook (hst-docs.stsci.edu/drizzpac) for all your drizzling questions!