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WFC3 Pipeline Calibration. Overall Architecture Use of Associations Outline of Processing Reuse of CALACS and CALNIC Code Processing Steps and Keywords Reference Files. CALWF3 Architecture. Code written in ANSI C Use CVOS and HSTIO interfaces to IRAF/TABLES libraries
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WFC3 Pipeline Calibration Overall Architecture Use of Associations Outline of Processing Reuse of CALACS and CALNIC Code Processing Steps and Keywords Reference Files
CALWF3 Architecture • Code written in ANSI C • Use CVOS and HSTIO interfaces to IRAF/TABLES libraries • All run-time data files in FITS format with extensions • Exposures consist of multiple-extension IMSETs • Use associations to process and combine related exposures CALWF3
CALWF3 Outline • Maximal reuse of ACS and NICMOS calibration software • CALWF3 based on CALACS flow model • Includes single and multiple image operations within one shell • UVIS and IR images treated as similarly as possible • UVIS identical to ACS WFC • IR similar to NICMOS • Grism/Prism images receive 2-D processing only; spectral extraction tools to be supplied by ST-ECF (as is the case for NICMOS & ACS) CALWF3
Basic Functions • Apply instrumental calibrations to individual images • Includes handling of binned and subarray images • Perform various types of combining for associated images • Combine UVIS CR-Splits and IR MultiAccums • Sum Repeat-Obs for UVIS and IR images • Drizzle Dithered UVIS and IR images • Interface to Drizzle module currently in development by ACS team for CALACS; adoption of CALACS backbone will allow for easy CALWF3 integration • Drizzle module can be used to perform geometric corrections CALWF3
Use of Associations • Associations will be used for: • CR-Splits • Repeat-Obs • Dither patterns • All possible combinations of the above • Associations will not be used for: • Mosaic patterns (logically-related exposures specified across >1 exposure logsheet line) • CALWF3 will use list of exposures in association table to identify files that need to be processed as groups & subgroups CALWF3
CALACS Flow Model Another Set of CR-SPLITS? CRCORR ACSCCD AtoD DQI Blev Bias Another Image in CR-SPLIT? Yes IR ACSREJ CR Rejection RPTCORR Yes ACSSUM DTHCORR Yes ACSDTH (Drizzle) Detector ACS2D Dark Flat Shad Phot CCD MAMA CALNICA DQI Nonlin Dark Flat Phot ACS2D DQI Nonlin Dark Flat Phot Another Image in Association? CALWF3
CALWF3 Flow Diagram ? Another Set of CR-SPLITS? CRCORR Detector WF3CCD Dark Flat Shad Phot WF3CCD AtoD DQI Blev Bias UVIS IR Another Image in CR-SPLIT? Yes WF3REJ CR Rejection WF3IR Zoff DQI Blev Bias Nlin Dark Flat Phot RPTCORR Yes Another Image in Association? WF3SUM DTHCORR Yes WF3DTH (Drizzle) CALWF3
Code Reuse • CALACS backbone used for overall flow control • CALACS module reuse: • acsccd: CALWF3 UVIS processing • acsrej: CALWF3 UVIS CR-Split combination • acssum: CALWF3 UVIS and IR Repeat-Obs combination • acsdth: CALWF3 UVIS and IR Dither combination • CALNICA reuse: • All applicable MultiAccum-mode calibration modules • No CALNICB reuse: • All image combination done via CALACS and Drizzle methods • Backwards compatibility with CALACS and CALNIC allows for easy implementation of future developments that are of value to WFC3 (e.g. NICMOS post-SAA persistence and pedestal corrections, ACS Drizzle development, etc.) CALWF3
Required Upgrades • UVIS binned images • STIS: calstis rebins reference data on-the-fly to match science images • ACS: no binning capabilities; reference data read line-by-line • WFC3: difficult to merge STIS on-the-fly rebinning with ACS line-by-line I/O; will be handled instead via binned reference data • IR subarray images • necessary for short exposures of bright standards • not supported in CALNIC; will use algorithms from CALACS WFC • IR overscan subtraction • used to track bias levels in each non-destructive readout • not supported in CALNIC; will use algorithms from CALACS WFC • Interface to Drizzle • currently under development for CALACS CALWF3
CALWF3 UVIS Cal Steps CALWF3
CALWF3 UVIS Steps (cont.) CALWF3
CALWF3 IR Cal Steps CALWF3
CALWF3 IR Cal Steps (cont.) CALWF3
CALWF3 Image Combining 1DITHCORR currently a stub in CALACS; drizzle algorithm development is in progress by ACS & SSG teams CALWF3
CALWF3 Reference Images 1Separate reference images will be maintained in CDBS for each binning mode. CALWF3
CALWF3 Reference Tables CALWF3
CALWF3 Ref Tables (cont.) CALWF3
CALWF3 Ref Tables (cont.) CALWF3
Test Plan • A comprehensive test plan will be created for UVIS and IR instrumental calibrations, as well as all image combination methods, to be executed and evaluated by WFC3 IPT • Tests will include: • Correct selection and sequence of calibration steps depending on science data input • Proper trapping and handling of common failure modes (e.g. missing, inappropriate reference data files, missing assocation members, missing or invalid keyword values, etc.) • Verification of intended scientific results from each operation • Correct generation of trailer files CALWF3