ISR 2023-08: WFC3/UVIS: New Full-Well Saturation Map Reference File
December 29, 2023I. Rivera, M. Marinelli, J. Mack
This report introduces the implementation of a new 2-dimensional saturation map for use in the calibration pipeline for the WFC3/UVIS detector. These changes were delivered in calwf3 v3.7.1 on December 7, 2023 for the reprocessing of all UVIS data in the Mikulski Archive for Space Telescopes (MAST). Similar to recent updates to the calacs pipeline, a new SATUFILE reference file will be used for flagging pixels in the data quality (DQ) array of calibrated images which exceed the full-well limit. The updated version of calwf3 with the new SATUFILE effectively flags the same saturated pixels as older versions of calwf3 using the previous method that applied a single saturation threshold from the CCDTAB reference file. Since the DQ flags do not change with this version of the SATUFILE, users will not need to retrieve the updated products from MAST. For products that are missing the SATUFILE keyword, the new calwf3 will revert to using the CCDTAB threshold value. In the future, improved pixel flagging will be possible by updating this 2D saturation map reference file.