Overall ArchitectureOverall Architecture Outline of ProcessingOutline of Processing Reuse of CALACS and CALNIC CodeReuse of CALACS and CALNIC Code Processing Steps and KeywordsProcessing Steps and Keywords Reference FilesReference Files WFC3 Pipeline Calibration

WFC3 PIPELINE CDR H. Bushouse October 16, 2001 CALWF32 Introductory Remarks This review covers only those portions of CALWF3 that will apply instrumental calibrations and combine stacked images (i.e. CR-SPLITs and REPEAT-OBS)This review covers only those portions of CALWF3 that will apply instrumental calibrations and combine stacked images (i.e. CR-SPLITs and REPEAT-OBS) –“Value added” portions – distortion correction and combination of dithered/mosaiced images – To Be Reviewed Later [TBRL] AV-03AV-03 –Data calibration requirements and specifications WFC3 design based on ACS & NICMOS, developed by:WFC3 design based on ACS & NICMOS, developed by: –Hack, Greenfield, Stiavelli, Clampin –Skinner, Bushouse, MacKenty, Axon

WFC3 PIPELINE CDR H. Bushouse October 16, 2001 CALWF33 Basic Functions Apply instrumental calibrations to individual imagesApply instrumental calibrations to individual images –must include handling of binned and subarray images –combination of IR MultiAccum readouts into single image Perform various types of combining for associated imagesPerform various types of combining for associated images –combine CR-SPLIT and REPEAT-OBS images – [] –combine dithered/mosaiced images [TBRL] Grism/Prism images receive 2-D processing only; agreement in progress for spectral extraction/analysis tools to be supplied by ST-ECF (reuse of ST-ECF supplied ACS tools)Grism/Prism images receive 2-D processing only; agreement in progress for spectral extraction/analysis tools to be supplied by ST-ECF (reuse of ST-ECF supplied ACS tools)

WFC3 PIPELINE CDR H. Bushouse October 16, 2001 CALWF34 CALWF3 Overview CALWF3 code written in ANSI CCALWF3 code written in ANSI C –no new languages! Uses association tables to control processing of logically related exposuresUses association tables to control processing of logically related exposures Maximal reuse of ACS and NICMOS calibration softwareMaximal reuse of ACS and NICMOS calibration software CALWF3 based on CALACS flow modelCALWF3 based on CALACS flow model Single and multiple image operations integrated within one shellSingle and multiple image operations integrated within one shell –no “a” and “b” pieces like CALNIC UVIS and IR images treated as similarly as possibleUVIS and IR images treated as similarly as possible –UVIS identical to ACS WFC –IR nearly identical to NICMOS

WFC3 PIPELINE CDR H. Bushouse October 16, 2001 CALWF35 CALWF3 Flow Diagram WF3CCD DQI Blev Bias Flash Another Image In CR-SPLIT or RPT-OBS set? WF3CCD Dark Flat Shad Phot Another set of CR-SPLITs or RPT-OBS images? Another set of CR-SPLITs or RPT-OBS images? WF3DRZ Drizzling Yes DRZCORR WF3IR Zoff DQI Dark Blev Nlin Flat Phot Crrej Another Image in RPT-OBS set? RPTCORR WF3REJ CR Rejection Yes Another set of RPT-OBS images? UVIS IR Detector CRCORR WF3REJ CR Rejection Yes [TBRL]

WFC3 PIPELINE CDR H. Bushouse October 16, 2001 CALWF36 Code Reuse CALACS backbone used for overall flow controlCALACS backbone used for overall flow control CALACS module reuse:CALACS module reuse: –acsccd: CALWF3 UVIS processing –acsrej: CALWF3 CR-SPLIT & REPEAT-OBS combination CALNICA reuse:CALNICA reuse: –All applicable MultiAccum mode calibration modules Backwards compatibility with CALACS and CALNIC allows easy implementation of future developments of value to WFC3 (e.g. NICMOS post-SAA persistence corrections, ACS Drizzle development, etc.)Backwards compatibility with CALACS and CALNIC allows easy implementation of future developments of value to WFC3 (e.g. NICMOS post-SAA persistence corrections, ACS Drizzle development, etc.) Prototype version of CALWF3, constructed via merger of above ACS & NICMOS code, is up and running nowPrototype version of CALWF3, constructed via merger of above ACS & NICMOS code, is up and running now

WFC3 PIPELINE CDR H. Bushouse October 16, 2001 CALWF37 Required Upgrades UVIS binned imagesUVIS binned images –ACS: no binning capabilities –WFC3: will be handled via binned reference data No new code necessaryNo new code necessary “safe” approach in case calibrations are binning dependent“safe” approach in case calibrations are binning dependent IR subarray imagesIR subarray images –necessary for short exposures of bright standards –not supported in CALNIC; will use algorithms from CALACS IR reference pixel subtractionIR reference pixel subtraction –used to track bias levels in each non-destructive readout –new capability; need to develop new methods (in progress)

WFC3 PIPELINE CDR H. Bushouse October 16, 2001 CALWF38 IR Reference Pixels Reference pixels located in outer 5 rows and columns of arrayReference pixels located in outer 5 rows and columns of array 5 different “flavors” (unique capacitance)5 different “flavors” (unique capacitance) Outermost row and column steps through 4 capacitancesOutermost row and column steps through 4 capacitances Rows and columns 2-5 have same capacitanceRows and columns 2-5 have same capacitance Take quadrant mean or median of best fitting set and subtractTake quadrant mean or median of best fitting set and subtract Column DCBADCBADCBADCBA Active Reference Row E E E E E E E E E B C D A B C D

WFC3 PIPELINE CDR H. Bushouse October 16, 2001 CALWF39 Flat Field Strategy Will use same approach as WFPC2 and ACS: Flats obtained and maintained in “raw” space, i.e. pixels with larger projected area have more countsFlats obtained and maintained in “raw” space, i.e. pixels with larger projected area have more counts Division into raw science images produces constant counts per pixel for uniform extended sources, but leaves point sources incorrectDivision into raw science images produces constant counts per pixel for uniform extended sources, but leaves point sources incorrect Point source photometry will have to be corrected by other means (e.g. correction look-up tables or drizzle resampling)Point source photometry will have to be corrected by other means (e.g. correction look-up tables or drizzle resampling)

WFC3 PIPELINE CDR H. Bushouse October 16, 2001 CALWF310 Phased Implementation Initial delivery of “core” CALWF3 to DST in 2002 Q2Initial delivery of “core” CALWF3 to DST in 2002 Q2 –Includes basic UVIS and IR calibration capabilities –Supports testing of SLTV processing system Updates delivered 2003 Q2 based on SLTV experience, as well as 3-4 months post-launch (2004 Q2-3?) based on SMOV and early science experienceUpdates delivered 2003 Q2 based on SLTV experience, as well as 3-4 months post-launch (2004 Q2-3?) based on SMOV and early science experience

WFC3 PIPELINE CDR H. Bushouse October 16, 2001 CALWF311 CALWF3 UVIS Cal Steps Input Files Processing Step Keyword Switch Output File _asn or _raw CCDTAB Compute statistical errors (initialize ERR array) N/A BPIXTAB Assign static DQ flags (initialize DQ array) DQICORR OSCNTAB Overscan bias level subtraction BLEVCORR BIASFILE Bias image subtraction BIASCORR FLSHFILE Post-flash subtraction FLSHCORR_blv_tmp _blv_tmpCRREJTAB Combine CR-SPLIT or REPEAT- OBS images CRCORR_crj_tmp

WFC3 PIPELINE CDR H. Bushouse October 16, 2001 CALWF312 CALWF3 UVIS Steps (cont.) Input Files Processing Step Keyword Switch Output File _blv_tmp or _crj_tmp DARKFILE Dark Current Subtraction DARKCORR PFLTFILEDFLTFILELFLTFILE Flat Field Correction FLATCORR SHADFILE Shutter Shading Correction SHADCORR PHOTTAB Compute Photometric Parameters (populate PHOTxxxx keywords) PHOTCORR Compute Image Statistics STATFLAG _flt or _crj

WFC3 PIPELINE CDR H. Bushouse October 16, 2001 CALWF313 CALWF3 IR Cal Steps Input Files Processing Step Keyword Switch Output File _asn or _raw Zero-read signal correction ZSIGCORR Zero-read subtraction ZOFFCORR CCDTAB Compute statistical errors (initialize ERR arrays) N/A BPIXTAB Assign static DQ flags (initialize DQ arrays) DQICORR DARKFILE Dark subtraction DARKCORR OSCNTAB Residual bias subtraction BLEVCORR

WFC3 PIPELINE CDR H. Bushouse October 16, 2001 CALWF314 CALWF3 IR Cal Steps (cont.) Input Files Processing Step Keyword Switch Output File NLINFILE Non-Linearity Correction NLINCORR PFLTFILEDFLTFILELFLTFILE Flat Field Correction FLATCORR PHOTTAB Compute Photometric Parameters (populate PHOTxxxx keywords) PHOTCORR CRREJTAB Cosmic-Ray Rejection (also combines readouts) CRCORR Compute Image Statistics STATFLAG _ima and _flt _flt Combine REPEAT-OBS Images RPTCORR_crj

WFC3 PIPELINE CDR H. Bushouse October 16, 2001 CALWF315 CALWF3 Reference Images Image Name SuffixDescriptionUVISIR Selection Criteria BIASFILEbiaBias * DETECTOR GAIN BINAXIS 1 DARKFILEdrk Dark Current ** DETECTOR GAIN BINAXIS 1 SAMP_SEQ NLINFILElin Non-Linearity Coefficients * DETECTOR PFLTFILEpfl Pixel-to-Pixel Flat Field ** DETECTOR FILTER BINAXIS 1 DFLTFILEdfl Delta Flat Field ** DETECTOR FILTER BINAXIS 1 LFLTFILElfl Low-order Flat Field ** DETECTOR FILTER BINAXIS 1 SHADFILEshd Shutter Shading Correction * DETECTOR 1 Separate reference images will be maintained in CDBS for each binning mode.

WFC3 PIPELINE CDR H. Bushouse October 16, 2001 CALWF316 CALWF3 Reference Tables Table Name SuffixDescriptionUVISIRFileSelectorRowSelector Parameter Columns BPIXTABbpx Bad Pixel Table **DETECTORCCDCHIPCCDAMPPIX1PIX2LENGTHAXISVALUE CCDTABccd CCD Parameters **DETECTORCCDAMPCCDCHIPCCDGAINCCDOFSTBINAXIS1BINAXIS2ATODGAINCCDBIASREADNSESATURATEAMPXAMPY

WFC3 PIPELINE CDR H. Bushouse October 16, 2001 CALWF317 CALWF3 Ref Tables (cont.) Table Name SuffixDescriptionUVISIRFileSelectorRowSelector Parameter Columns CRREJTABcrr Cosmic-Ray Rejection Parameters**DETECTORCRSPLITMEANEXPSCALENSEINITGUESSSKYSUBCRSIGMASCRRADIUSCRTHRESHBADINPDQCRMASK IDCTABidc Image Distortion Coefficients**DETECTORFUNCTYPENCOEFF1COEFF1[ncoeff1]NCOEFF2COEFF2[ncoeff2]

WFC3 PIPELINE CDR H. Bushouse October 16, 2001 CALWF318 CALWF3 Ref Tables (cont.) Table Name SuffixDescriptionUVISIRFileSelectorRowSelector Parameter Columns OSCNTABosc Overscan Parameters **DETECTORCCDAMPCCDCHIPBINXBINY NX NY TRIMX[1,2]TRIMY[1,2]VX[1,2]VY[1,2]BIASSECTA[1,2]BIASSECTB[1,2] PHOTTABpht Photometry Parameters **DETECTORFILTERNELEMWAVELENGTHTHROUGHPUT