2.2 ACS File Structure
The ACS calibration pipeline assembles data received from HST into datasets, applies standard calibrations (so that calibrated image header keyword values can be entered in the Archive database), and stores uncalibrated datasets in the HST Data Archive. When a user requests data, it is fetched from the MAST static archive unless newer versions of the pipeline and/or calibration reference files are present. In the latter case, the requested data will be moved to the top of the reprocessing queue.
Data from the Archive arrives as multi-extension FITS files that have three main categories, as listed below (see Figure 2.1 for a graphical representation of this information). Single quotes around the extension names are required in Python usage.
- Global header extension ('PRIMARY'): this is always in extension [0], and contains a selection of header keyword values applicable to all information in the FITS file.
- Science image ('SCI'), error array ('ERR'), and data quality array ('DQ') extensions:
- HRC and SBC are single-detector channels. For these channels, the science image is in extension [1] or ['SCI',1], error array in extension [2] or ['ERR',1], and data quality array in extension [3] or ['DQ',1].
- WFC data comes from two chips, each with its own science, error, and data quality arrays. For WFC2, the science image is in extension [1] or ['SCI',1], error array in extension [2] or ['ERR',1], and data quality array in extension [3] or ['DQ',1]. For WFC1, the science image is in extension [4] or ['SCI',2], error array in extension [5] or ['ERR',2], and data quality array in extension [6] or ['DQ',2]. See Figure 2.2 for a visual representation of the WFC chips projected onto the V2,V3 axis. Figure 2.2 shows the WFC apertures plotted with respect to the V2,V3 reference frame, and oriented such that the x-axis runs approximately towards the right and the y-axis runs approximately straight up. In pipeline data products, WFC2 is displayed below WFC1 (along the y-axis) and is therefore designated as extension 1.
- AstroDrizzle extensions:
- Drizzled data from the pipeline have the suffix
drz.fits
, and additionallydrc.fits
for WFC CTE-corrected data. These products are delivered as multi-extension FITS files with three image data extensions: science image ['SCI'], weight image ['WHT'], and context image ['CTX']. However, AstroDrizzle also adds new FITS extensions to theflt.fits/flc.fits
anddrz.fits/drc.fits
files, as summarized below. For more information on drizzled data, please refer to the Drizzlepac Handbook. - For
flt.fits/flc.fits
images: during OTFR processing, AstroDrizzle updates the WCS of these images with distortion corrections. Linear distortion corrections (scale, rotation, and time-dependent skew) are incorporated into the CD-Matrix. Coefficients for higher order polynomial functions that describe the distortion corrections are stored as SIP1 header keyword values. Some distortion corrections, however, cannot be expressed as equations and have to be stored in array form as FITS extensions. - The ['D2IMARR'] fits extensions are tabular data required only for WFC, with one extension per chip axis. They are filter-independent corrections for the CCD pixel-grid irregularities resulting from the manufacturing process and contain both X and Y corrections for each WFC CCD chip.
- The ['WCSDVARR'] fits extensions, with one extension per chip axis, hold tabular data which describe small-scale distortions due to filter-dependent non-polynomial distortion corrections which include both X and Y corrections for each WFC CCD chip. Therefore, a WFC
flt.fits/flc.fits
image has four ['WCSDVARR'] extensions while HRC and SBC only have two ['WCSDVARR'] extensions. - If the data were reprocessed with a new distortion correction reference file, a FITS extension called ['WCSCORR'] is added that contains a history of WCS changes.
- Several ['HEADERLET'] FITS extensions containing WCS transformations that can be applied as the primary WCS. For more detailed information please consult the Hubble Advanced Products (HAP) headerlets page.
- For
drz.fit/drc.fits
images: a fourth extension has been added, called ['HDRTAB'], which is a compilation of important header keywords that have unique values for each input image.
- Drizzled data from the pipeline have the suffix
The number of headerlets may vary from image to image depending on what has been done to it. Here below is the header listing of a standard *_flc.fits file and for comparison farther below, the header listing of a standard *_drc.fits file.
Python INPUT:
from astropy.io import fits fits_image_filename = ('jcsz32diq_flc.fits') with fits.open(fits_image_filename) as hdul: hdul.info() hdul.close()
Python OUTPUT:
Filename: jcsz32diq_flc.fits No. Name Type Cards Dimensions Format 0 PRIMARY PrimaryHDU 289 () 1 SCI ImageHDU 241 (4096, 2048) float32 2 ERR ImageHDU 53 (4096, 2048) float32 3 DQ ImageHDU 45 (4096, 2048) int16 4 SCI ImageHDU 239 (4096, 2048) float32 5 ERR ImageHDU 53 (4096, 2048) float32 6 DQ ImageHDU 45 (4096, 2048) int16 7 D2IMARR ImageHDU 16 (64, 32) float32 8 D2IMARR ImageHDU 16 (64, 32) float32 9 D2IMARR ImageHDU 16 (64, 32) float32 10 D2IMARR ImageHDU 16 (64, 32) float32 11 WCSDVARR ImageHDU 16 (64, 32) float32 12 WCSDVARR ImageHDU 16 (64, 32) float32 13 WCSDVARR ImageHDU 16 (64, 32) float32 14 WCSDVARR ImageHDU 16 (64, 32) float32 15 HDRLET NonstandardExtHDU 18 () 16 HDRLET NonstandardExtHDU 26 () 17 WCSCORR BinTableHDU 59 14R x 24C [40A, I, A, 24A, 24A, 24A, 24A, D, D, D, D, D, D, D, D, 24A, 24A, D, D, D, D, J, 40A, 128A] 18 HDRLET NonstandardExtHDU 26 () 19 HDRLET NonstandardExtHDU 26 ()
Similarly, one may list the header groups of a *_drc.fits image.
Python INPUT:
from astropy.io import fits fits_image_filename = ('jcsz32010_drc.fits') with fits.open(fits_image_filename) as hdul: hdul.info() hdul.close()
Python OUTPUT:
Filename: jcsz32010_drc.fits No. Name Type Cards Dimensions Format 0 PRIMARY PrimaryHDU 856 () 1 SCI ImageHDU 81 (4222, 4334) float32 2 WHT ImageHDU 44 (4222, 4334) float32 3 CTX ImageHDU 37 (4222, 4334) int32 4 HDRTAB BinTableHDU 633 8R x 312C [9A, 3A, K, D, D, D, D, D, D, D, D, D, D, D, D, D, K, 8A, 9A, 7A, 18A, 4A, D, D, D, D, 3A, D, D, D, D, D, D, D, D, D, D, D, D, K, 8A, 23A, D, D, D, D, K, K, K, 8A, K, 23A, 9A, 20A, K, 4A, K, D, K, K, K, K, 23A, D, D, D, D, K, K, 3A, 3A, 4A, 4A, L, D, D, D, 3A, 1A, K, D, D, D, 13A, 3A, 4A, 4A, 12A, 12A, 23A, 8A, 23A, 10A, 10A, D, D, 3A, 3A, 23A, 4A, 8A, 7A, 23A, D, K, D, 6A, 9A, 8A, D, D, L, 4A, 18A, 3A, K, 5A, 7A, 3A, D, 13A, 8A, 4A, 3A, L, K, L, K, L, K, K, D, D, D, D, D, D, 3A, 1A, D, 23A, D, D, D, 3A, 23A, L, 1A, 3A, 6A, D, 3A, 6A, K, D, D, D, D, D, D, D, D, D, D, 23A, D, D, D, D, 3A, D, D, D, 1A, K, K, K, K, K, K, 23A, K, 5A, 7A, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, 13A, D, 24A, 23A, D, 1A, 1A, D, K, D, D, 1A, 1A, D, 4A, K, D, K, 8A, D, D, D, D, D, 23A, 23A, D, 8A, D, 29A, D, 3A, D, L, D, D, 3A, 8A, 4A, 1A, D, 8A, K, 1A, 1A, 1A, 1A, D, D, D, D, D, D, 4A, D, 4A, D, 4A, K, 4A, 3A, 1A, L, K, K, 1A, D, D, D, D, K, 3A, L, L, 6A, L, D, D, 9A, D, D, 3A, 8A, 1A, D, K, D, L, 30A, L, 5A, 4A, K, D, D, D, D, D, D, D, D, D, D, D, D, D, D, 8A, 8A, 3A, 3A]
One can also look for a specific keyword in a specific extension, such as the GAIN value in the Group 0 header extension here.
Python INPUT:
from astropy.io import fits fits_image_filename = ('jcsz32010_drc.fits') with fits.open(fits_image_filename) as hdu1: print(hdu1[0].header['CCDGAIN'])
Python INPUT:
2.0
One can also look at the full header contents for a specific extension, in this case below, the Group 0 extension.
Python INPUT:
from astropy.io import fits fits_image_filename = 'jcsz32010_drc.fits' with fits.open(fits_image_filename) as hdu1: hdr = hdu1[0].header hdr
Python OUTPUT:
SIMPLE = T / conforms to FITS standard BITPIX = 8 / array data type NAXIS = 0 / number of array dimensions EXTEND = T COMMENT FITS (Flexible Image Transport System) format is defined in 'Astronomy COMMENT and Astrophysics', volume 376, page 359; bibcode: 2001A&A...376..359H TELESCOP= 'HST' / telescope used to acquire data INSTRUME= 'ACS ' / identifier for instrument used to acquire data / DATA DESCRIPTION KEYWORDS IMAGETYP= 'EXT ' / type of exposure identifier PRIMESI = 'ACS ' / instrument designated as prime / TARGET INFORMATION TARGNAME= 'ABELL-370 ' / proposer's target name / PROPOSAL INFORMATION PROPOSID= 14038 / PEP proposal identifier / EXPOSURE INFORMATION SUNANGLE= 92.396057 / angle between sun and V1 axis MOONANGL= 101.841713 / angle between moon and V1 axis SUN_ALT = 93.186295 / altitude of the sun above Earth's limb FGSLOCK = 'FINE ' / commanded FGS lock (FINE,COARSE,GYROS,UNKNOWN) GYROMODE= 'T' / number of gyros scheduled, T=3+OBAD DATE-OBS= '2016-01-25' / UT date of start of observation (yyyy-mm-dd) EXPSTART= 5.741240408115E+04 / exposure start time (Modified Julian Date) EXPEND = 57412.49923216 / exposure end time (Modified Julian Date) EXPTIME = 5146.0 / exposure duration (seconds)--calculated TEXPTIME= 5146.0 EXPFLAG = 'NORMAL ' / Exposure interruption indicator DARKTIME= 1.2284331E+03 / fiducial pixel dark time (secs) / POINTING INFORMATION / TARGET OFFSETS (POSTARGS) POSTARG1= 0.677630 / POSTARG in axis 1 direction POSTARG2= 10.565430 / POSTARG in axis 2 direction / DIAGNOSTIC KEYWORDS AWSYSVER= 'v0.4.33 ' / cloud infrastructure package version AWSDPVER= 'v0.2.16 ' / cloud docker image version CSYS_VER= 'caldp_20211129' / calibration software system version id / SCIENCE INSTRUMENT CONFIGURATION OBSTYPE = 'IMAGING ' / observation type - imaging or spectroscopic OBSMODE = 'ACCUM ' / operating mode CTEIMAGE= 'NONE' / type of Charge Transfer Image, if applicable SCLAMP = 'NONE ' / lamp status, NONE or name of lamp which is on NRPTEXP = 1 / number of repeat exposures in set: default 1 SUBARRAY= F / data from a subarray (T) or full frame (F) DETECTOR= 'WFC' / detector in use: WFC, HRC, or SBC FILTER1 = 'F606W ' / element selected from filter wheel 1 FILTER2 = 'CLEAR2L ' / element selected from filter wheel 2 FW1OFFST= 0 / computed filter wheel offset FW1ERROR= F / filter wheel position error flag FW2OFFST= -4320 / computed filter wheel offset FW2ERROR= T / filter wheel position error flag FWSOFFST= 0 / computed filter wheel offset FWSERROR= F / filter wheel position error flag LRFWAVE = 0.000000 / proposed linear ramp filter wavelength APERTURE= 'WFCENTER ' / aperture name PROPAPER= 'WFCENTER ' / proposed aperture name DIRIMAGE= 'NONE ' / direct image for grism or prism exposure CTEDIR = 'NONE ' / CTE measurement direction: serial or parallel CRSPLIT = 1 / number of cosmic ray split exposures / CALIBRATION SWITCHES: PERFORM, OMIT, COMPLETE WRTERR = T / write out error array extension DQICORR = 'COMPLETE' / data quality initialization ATODCORR= 'OMIT ' / correct for A to D conversion errors BLEVCORR= 'COMPLETE' / subtract bias level computed from overscan img BIASCORR= 'COMPLETE' / Subtract bias image FLSHCORR= 'OMIT ' / post flash correction CRCORR = 'OMIT ' / combine observations to reject cosmic rays EXPSCORR= 'COMPLETE' / process individual observations after cr-reject SHADCORR= 'OMIT ' / apply shutter shading correction DARKCORR= 'COMPLETE' / Subtract dark image FLATCORR= 'COMPLETE' / flat field data PHOTCORR= 'COMPLETE' / populate photometric header keywords DRIZCORR= 'COMPLETE' / drizzle processing SINKCORR= 'COMPLETE' / flag sink pixels / CALIBRATION REFERENCE FILES BPIXTAB = 'jref$25g1256nj_bpx.fits' / bad pixel table CCDTAB = 'jref$44h1714cj_ccd.fits' / CCD calibration parameters ATODTAB = 'N/A ' / analog to digital correction file OSCNTAB = 'jref$17717071j_osc.fits' / CCD overscan table BIASFILE= 'jref$25e1534mj_bia.fits' / bias image file name FLSHFILE= 'N/A ' / post flash correction file name CRREJTAB= 'N/A ' / cosmic ray rejection parameters SHADFILE= 'N/A ' / shutter shading correction file DARKFILE= 'jref$4b70022fj_drk.fits' / dark image file name DFLTFILE= 'N/A ' / delta flat field file name LFLTFILE= 'N/A ' / low order flat PHOTTAB = 'N/A ' / Photometric throughput table GRAPHTAB= 'N/A ' / the HST graph table COMPTAB = 'N/A ' / the HST components table IDCTAB = 'jref$4bb1536cj_idc.fits' / image distortion correction table DGEOFILE= 'jref$qbu16424j_dxy.fits' / Distortion correction image MDRIZTAB= 'jref$37g1550cj_mdz.fits' / MultiDrizzle parameter table CFLTFILE= 'N/A ' / Coronagraphic spot image SPOTTAB = 'N/A ' / Coronagraphic spot offset table IMPHTTAB= 'jref$4af1559ij_imp.fits' / Image Photometry Table SNKCFILE= 'jref$25e1528hj_snk.fits' / Map of sink pixels SATUFILE= 'jref$5331917aj_sat.fits' / CCD pixel saturation onset map / COSMIC RAY REJECTION ALGORITHM PARAMETERS MEANEXP = 0.000000 / reference exposure time for parameters SCALENSE= 0.000000 / multiplicative scale factor applied to noise SKYSUB = ' ' / sky value subtracted (MODE or NONE) SKYSUM = 0.0 / sky level from the sum of all constituent image CRRADIUS= 0.000000 / rejection propagation radius (pixels) CRTHRESH= 0.000000 / rejection propagation threshold BADINPDQ= 0 / data quality flag bits to reject REJ_RATE= 0.0 / rate at which pixels are affected by cosmic ray CRMASK = F / flag CR-rejected pixels in input files (T/F) / OTFR KEYWORDS / PATTERN KEYWORDS PATTERN1= 'NONE ' / primary pattern type P1_SHAPE= ' ' / primary pattern shape P1_PURPS= ' ' / primary pattern purpose P1_NPTS = 0 / number of points in primary pattern P1_PSPAC= 0.000000 / point spacing for primary pattern (arc-sec) P1_LSPAC= 0.000000 / line spacing for primary pattern (arc-sec) P1_ANGLE= 0.000000 / angle between sides of parallelogram patt (deg) P1_FRAME= ' ' / coordinate frame of primary pattern P1_ORINT= 0.000000 / orientation of pattern to coordinate frame (deg P1_CENTR= ' ' / center pattern relative to pointing (yes/no) PATTSTEP= 0 / position number of this point in the pattern / POST FLASH PARAMETERS FLASHDUR= 0.0 / Exposure time in seconds: 0.1 to 409.5 FLASHCUR= 'OFF ' / Post flash current: OFF, LOW, MED, HIGH FLASHSTA= 'NOT PERFORMED ' / Status: SUCCESSFUL, ABORTED, NOT PERFORMED SHUTRPOS= 'MULTIPLE' / Shutter position: A or B NSHUTOPN= 1 / Number of times shutter opened / ENGINEERING PARAMETERS CCDGAIN = 2.0 / commanded gain of CCD CCDOFSTA= 1 / commanded CCD bias offset for amplifier A CCDOFSTB= 1 / commanded CCD bias offset for amplifier B CCDOFSTC= 1 / commanded CCD bias offset for amplifier C CCDOFSTD= 1 / commanded CCD bias offset for amplifier D / CALIBRATED ENGINEERING PARAMETERS ATODGNA = 2.0200000E+00 / calibrated gain for amplifier A ATODGNB = 1.8860000E+00 / calibrated gain for amplifier B ATODGNC = 2.0170000E+00 / calibrated gain for amplifier C ATODGND = 2.0109999E+00 / calibrated gain for amplifier D READNSEA= 4.3499999E+00 / calibrated read noise for amplifier A READNSEB= 3.7500000E+00 / calibrated read noise for amplifier B READNSEC= 4.0500002E+00 / calibrated read noise for amplifier C READNSED= 5.0500002E+00 / calibrated read noise for amplifier D / ASSOCIATION KEYWORDS CRDS_CTX= 'hst_0972.pmap' CRDS_VER= '11.4.3, b11.4.0, 64d96076d89b32a5687a6b77bb910ab93b3a99b3' UPWCSVER= '1.7.2 ' / Version of STWCS used to update the WCS PYWCSVER= '4.3.1 ' / Version of Astropy used to update the WCS HISTORY CCD parameters table: HISTORY reference table jref$44h1714cj_ccd.fits HISTORY inflight HISTORY July 2009 HISTORY DQICORR complete ... HISTORY values checked for saturation HISTORY DQ array initialized ... HISTORY reference table jref$25g1256nj_bpx.fits HISTORY BIASCORR complete ... HISTORY reference image jref$25e1534mj_bia.fits HISTORY INFLIGHT 13/01/2016 10/02/2016 HISTORY Standard full-frame bias for data taken after Jan 13 2016 01:33:37- HISTORY DESTRIPE: number of rows fixed per amp: 2047 HISTORY DESTRIPE: number of rows skipped per amp: 21 HISTORY BLEVCORR complete; bias level from overscan was subtracted. HISTORY BLEVCORR does not include correction for drift along lines. HISTORY Overscan region table: HISTORY reference table jref$17717071j_osc.fits HISTORY Uncertainty array initialized. HISTORY SINKCORR complete ... HISTORY reference image jref$25e1528hj_snk.fits HISTORY INFLIGHT 13/01/2016 10/02/2016 HISTORY Sink pixel reference file ---------------------------- HISTORY CCD parameters table: HISTORY reference table jref$44h1714cj_ccd.fits HISTORY inflight HISTORY July 2009 HISTORY CTE_NAME PixelCTE 2017 CTE algorithm name HISTORY CTE_VER 2.0 CTE algorithm version HISTORY CTEDATE0 5.233486000000E+04 Date of instrument installation HISTORY PCTETRSH -1.000000000000E+01 CTE over subtraction threshold HISTORY CTEDATE1 5.771044601020E+04 Date of CTE model pinning HISTORY PCTEFRAC 9.445563835308E-01 CTE scaling factor HISTORY PCTETLEN 60 max length of CTE trail HISTORY PCTENFOR 5 Number of iter in forward model HISTORY PCTENPAR 7 Number of iter in parallel transfer HISTORY FIXROCR 1 fix readout cosmic rays HISTORY PCTECORR complete ... HISTORY PCTERNOI 4.3499999E+00 Amp 'A' read noise clip limit (from CCDTAB). HISTORY PCTERNOI 3.7500000E+00 Amp 'B' read noise clip limit (from CCDTAB). HISTORY PCTERNOI 4.0500002E+00 Amp 'C' read noise clip limit (from CCDTAB). HISTORY PCTERNOI 5.0500002E+00 Amp 'D' read noise clip limit (from CCDTAB). HISTORY CTE parameters table: HISTORY reference table jref$19i16323j_cte.fits DISTNAME= 'jcsz32dcq_4bb1536cj-4bb1536ej-4bb15371j' SIPNAME = 'jcsz32dcq_4bb1536cj' RULESVER= 1.1 / Version ID for header kw rules file BLENDVER= '1.2.0 ' / Version of blendheader software used RULEFILE= '/opt/conda/lib/python3.8/site-packages/fitsblender/acs_header.rules' NEXTEND = 4 FILENAME= 'jcsz32010_drc.fits' PROD_VER= 'DrizzlePac 3.3.1' DRIZPARS= 'jcsz32010.tra' / Logfile for processing ROOTNAME= 'jcsz32010_drc.fits' ASN_MTYP= 'PROD-DTH' NDRIZIM = 8 / Drizzle, No. images drizzled onto output D001VER = 'Callable C-based DRIZZLE Version 0.8 (20th May 2009)' / Drizzle, task D001GEOM= 'wcs ' / Drizzle, source of geometric information D001DATA= 'jcsz32dcq_flc.fits[sci,1]' / Drizzle, input data image D001DEXP= 1225.0 / Drizzle, input image exposure time (s) D001OUDA= 'jcsz32010_drc.fits' / Drizzle, output data image D001OUWE= 'jcsz32010_drc_wht.fits' / Drizzle, output weighting image D001OUCO= 'jcsz32010_drc_ctx.fits' / Drizzle, output context image D001MASK= 'jcsz32dcq_sci1_final_mask.fits' / Drizzle, input weighting image D001WTSC= 1 / Drizzle, weighting factor for input image D001KERN= 'square ' / Drizzle, form of weight distribution kernel D001PIXF= 1.0 / Drizzle, linear size of drop D001COEF= 'SIP ' / Drizzle, source of coefficients D001OUUN= 'cps ' / Drizzle, units of output image - counts or cps D001FVAL= 'INDEF ' / Drizzle, fill value for zero weight output pix D001WKEY= '' / Input image WCS Version used D001SCAL= 0.05 / Drizzle, pixel size (arcsec) of output image D001ISCL= 0.05 / Drizzle, default IDCTAB pixel size(arcsec) D002VER = 'Callable C-based DRIZZLE Version 0.8 (20th May 2009)' / Drizzle, task D002GEOM= 'wcs ' / Drizzle, source of geometric information D002DATA= 'jcsz32dcq_flc.fits[sci,2]' / Drizzle, input data image D002DEXP= 1225.0 / Drizzle, input image exposure time (s) D002OUDA= 'jcsz32010_drc.fits' / Drizzle, output data image D002OUWE= 'jcsz32010_drc_wht.fits' / Drizzle, output weighting image D002OUCO= 'jcsz32010_drc_ctx.fits' / Drizzle, output context image D002MASK= 'jcsz32dcq_sci2_final_mask.fits' / Drizzle, input weighting image D002WTSC= 1 / Drizzle, weighting factor for input image D002KERN= 'square ' / Drizzle, form of weight distribution kernel D002PIXF= 1.0 / Drizzle, linear size of drop D002COEF= 'SIP ' / Drizzle, source of coefficients D002OUUN= 'cps ' / Drizzle, units of output image - counts or cps D002FVAL= 'INDEF ' / Drizzle, fill value for zero weight output pix D002WKEY= '' / Input image WCS Version used D002SCAL= 0.05 / Drizzle, pixel size (arcsec) of output image D002ISCL= 0.05 / Drizzle, default IDCTAB pixel size(arcsec) D003VER = 'Callable C-based DRIZZLE Version 0.8 (20th May 2009)' / Drizzle, task D003GEOM= 'wcs ' / Drizzle, source of geometric information D003DATA= 'jcsz32deq_flc.fits[sci,1]' / Drizzle, input data image D003DEXP= 1307.0 / Drizzle, input image exposure time (s) D003OUDA= 'jcsz32010_drc.fits' / Drizzle, output data image D003OUWE= 'jcsz32010_drc_wht.fits' / Drizzle, output weighting image D003OUCO= 'jcsz32010_drc_ctx.fits' / Drizzle, output context image D003MASK= 'jcsz32deq_sci1_final_mask.fits' / Drizzle, input weighting image D003WTSC= 1 / Drizzle, weighting factor for input image D003KERN= 'square ' / Drizzle, form of weight distribution kernel D003PIXF= 1.0 / Drizzle, linear size of drop D003COEF= 'SIP ' / Drizzle, source of coefficients D003OUUN= 'cps ' / Drizzle, units of output image - counts or cps D003FVAL= 'INDEF ' / Drizzle, fill value for zero weight output pix D003WKEY= '' / Input image WCS Version used D003SCAL= 0.05 / Drizzle, pixel size (arcsec) of output image D003ISCL= 0.05 / Drizzle, default IDCTAB pixel size(arcsec) D004VER = 'Callable C-based DRIZZLE Version 0.8 (20th May 2009)' / Drizzle, task D004GEOM= 'wcs ' / Drizzle, source of geometric information D004DATA= 'jcsz32deq_flc.fits[sci,2]' / Drizzle, input data image D004DEXP= 1307.0 / Drizzle, input image exposure time (s) D004OUDA= 'jcsz32010_drc.fits' / Drizzle, output data image D004OUWE= 'jcsz32010_drc_wht.fits' / Drizzle, output weighting image D004OUCO= 'jcsz32010_drc_ctx.fits' / Drizzle, output context image D004MASK= 'jcsz32deq_sci2_final_mask.fits' / Drizzle, input weighting image D004WTSC= 1 / Drizzle, weighting factor for input image D004KERN= 'square ' / Drizzle, form of weight distribution kernel D004PIXF= 1.0 / Drizzle, linear size of drop D004COEF= 'SIP ' / Drizzle, source of coefficients D004OUUN= 'cps ' / Drizzle, units of output image - counts or cps D004FVAL= 'INDEF ' / Drizzle, fill value for zero weight output pix D004WKEY= '' / Input image WCS Version used D004SCAL= 0.05 / Drizzle, pixel size (arcsec) of output image D004ISCL= 0.05 / Drizzle, default IDCTAB pixel size(arcsec) D005VER = 'Callable C-based DRIZZLE Version 0.8 (20th May 2009)' / Drizzle, task D005GEOM= 'wcs ' / Drizzle, source of geometric information D005DATA= 'jcsz32diq_flc.fits[sci,1]' / Drizzle, input data image D005DEXP= 1307.0 / Drizzle, input image exposure time (s) D005OUDA= 'jcsz32010_drc.fits' / Drizzle, output data image D005OUWE= 'jcsz32010_drc_wht.fits' / Drizzle, output weighting image D005OUCO= 'jcsz32010_drc_ctx.fits' / Drizzle, output context image D005MASK= 'jcsz32diq_sci1_final_mask.fits' / Drizzle, input weighting image D005WTSC= 1 / Drizzle, weighting factor for input image D005KERN= 'square ' / Drizzle, form of weight distribution kernel D005PIXF= 1.0 / Drizzle, linear size of drop D005COEF= 'SIP ' / Drizzle, source of coefficients D005OUUN= 'cps ' / Drizzle, units of output image - counts or cps D005FVAL= 'INDEF ' / Drizzle, fill value for zero weight output pix D005WKEY= '' / Input image WCS Version used D005SCAL= 0.05 / Drizzle, pixel size (arcsec) of output image D005ISCL= 0.05 / Drizzle, default IDCTAB pixel size(arcsec) D006VER = 'Callable C-based DRIZZLE Version 0.8 (20th May 2009)' / Drizzle, task D006GEOM= 'wcs ' / Drizzle, source of geometric information D006DATA= 'jcsz32diq_flc.fits[sci,2]' / Drizzle, input data image D006DEXP= 1307.0 / Drizzle, input image exposure time (s) D006OUDA= 'jcsz32010_drc.fits' / Drizzle, output data image D006OUWE= 'jcsz32010_drc_wht.fits' / Drizzle, output weighting image D006OUCO= 'jcsz32010_drc_ctx.fits' / Drizzle, output context image D006MASK= 'jcsz32diq_sci2_final_mask.fits' / Drizzle, input weighting image D006WTSC= 1 / Drizzle, weighting factor for input image D006KERN= 'square ' / Drizzle, form of weight distribution kernel D006PIXF= 1.0 / Drizzle, linear size of drop D006COEF= 'SIP ' / Drizzle, source of coefficients D006OUUN= 'cps ' / Drizzle, units of output image - counts or cps D006FVAL= 'INDEF ' / Drizzle, fill value for zero weight output pix D006WKEY= '' / Input image WCS Version used D006SCAL= 0.05 / Drizzle, pixel size (arcsec) of output image D006ISCL= 0.05 / Drizzle, default IDCTAB pixel size(arcsec) D007VER = 'Callable C-based DRIZZLE Version 0.8 (20th May 2009)' / Drizzle, task D007GEOM= 'wcs ' / Drizzle, source of geometric information D007DATA= 'jcsz32dlq_flc.fits[sci,1]' / Drizzle, input data image D007DEXP= 1307.0 / Drizzle, input image exposure time (s) D007OUDA= 'jcsz32010_drc.fits' / Drizzle, output data image D007OUWE= 'jcsz32010_drc_wht.fits' / Drizzle, output weighting image D007OUCO= 'jcsz32010_drc_ctx.fits' / Drizzle, output context image D007MASK= 'jcsz32dlq_sci1_final_mask.fits' / Drizzle, input weighting image D007WTSC= 1 / Drizzle, weighting factor for input image D007KERN= 'square ' / Drizzle, form of weight distribution kernel D007PIXF= 1.0 / Drizzle, linear size of drop D007COEF= 'SIP ' / Drizzle, source of coefficients D007OUUN= 'cps ' / Drizzle, units of output image - counts or cps D007FVAL= 'INDEF ' / Drizzle, fill value for zero weight output pix D007WKEY= '' / Input image WCS Version used D007SCAL= 0.05 / Drizzle, pixel size (arcsec) of output image D007ISCL= 0.05 / Drizzle, default IDCTAB pixel size(arcsec) D008VER = 'Callable C-based DRIZZLE Version 0.8 (20th May 2009)' / Drizzle, task D008GEOM= 'wcs ' / Drizzle, source of geometric information D008DATA= 'jcsz32dlq_flc.fits[sci,2]' / Drizzle, input data image D008DEXP= 1307.0 / Drizzle, input image exposure time (s) D008OUDA= 'jcsz32010_drc.fits' / Drizzle, output data image D008OUWE= 'jcsz32010_drc_wht.fits' / Drizzle, output weighting image D008OUCO= 'jcsz32010_drc_ctx.fits' / Drizzle, output context image D008MASK= 'jcsz32dlq_sci2_final_mask.fits' / Drizzle, input weighting image D008WTSC= 1 / Drizzle, weighting factor for input image D008KERN= 'square ' / Drizzle, form of weight distribution kernel D008PIXF= 1.0 / Drizzle, linear size of drop D008COEF= 'SIP ' / Drizzle, source of coefficients D008OUUN= 'cps ' / Drizzle, units of output image - counts or cps D008FVAL= 'INDEF ' / Drizzle, fill value for zero weight output pix D008WKEY= '' / Input image WCS Version used D008SCAL= 0.05 / Drizzle, pixel size (arcsec) of output image D008ISCL= 0.05 / Drizzle, default IDCTAB pixel size(arcsec) HISTORY CCD parameters table: HISTORY reference table jref$44h1714cj_ccd.fits HISTORY inflight HISTORY July 2009 HISTORY DARKCORR complete ... HISTORY reference image jref$4b70021pj_dkc.fits HISTORY INFLIGHT 13/01/2016 10/02/2016 HISTORY CTE corrected dark for WFC data taken after Jan 13 2016 01:33:37--- HISTORY FLATCORR complete ... HISTORY reference image jref$qb12257sj_pfl.fits HISTORY INFLIGHT 18/04/2002 - 04/07/2006 HISTORY F606W step +1 flat w/ mote shifted to -1 step HISTORY PHOTCORR complete ... HISTORY reference table jref$4af1559ij_imp.fits HISTORY EXPSCORR complete ... HISTORY ============================================================ HISTORY Header Generation rules: HISTORY Rules used to combine headers of input files HISTORY Start of rules... HISTORY ------------------------------------------------------------ HISTORY !VERSION = 1.1 HISTORY !INSTRUMENT = ACS HISTORY ROOTNAME HISTORY EXTNAME HISTORY EXTVER HISTORY A_0_2 HISTORY A_0_3 HISTORY A_0_4 HISTORY A_1_1 HISTORY A_1_2 HISTORY A_1_3 HISTORY A_2_0 HISTORY A_2_1 HISTORY A_2_2 HISTORY A_3_0 HISTORY A_3_1 HISTORY A_4_0 HISTORY ACQNAME HISTORY A_ORDER HISTORY APERTURE HISTORY ASN_ID HISTORY ASN_MTYP HISTORY ASN_TAB HISTORY ATODCORR HISTORY ATODGNA HISTORY ATODGNB HISTORY ATODGNC HISTORY ATODGND HISTORY ATODTAB HISTORY B_0_2 HISTORY B_0_3 HISTORY B_0_4 HISTORY B_1_1 HISTORY B_1_2 HISTORY B_1_3 HISTORY B_2_0 HISTORY B_2_1 HISTORY B_2_2 HISTORY B_3_0 HISTORY B_3_1 HISTORY B_4_0 HISTORY BADINPDQ HISTORY BIASCORR HISTORY BIASFILE HISTORY BIASLEVA HISTORY BIASLEVB HISTORY BIASLEVC HISTORY BIASLEVD HISTORY BINAXIS1 HISTORY BINAXIS2 HISTORY BITPIX HISTORY BLEVCORR HISTORY B_ORDER HISTORY BPIXTAB HISTORY BUNIT HISTORY CAL_VER HISTORY CBLKSIZ HISTORY CCDAMP HISTORY CCDCHIP HISTORY CCDGAIN HISTORY CCDOFSTA HISTORY CCDOFSTB HISTORY CCDOFSTC HISTORY CCDOFSTD HISTORY CCDTAB HISTORY CD1_1 HISTORY CD1_2 HISTORY CD2_1 HISTORY CD2_2 HISTORY CENTERA1 HISTORY CENTERA2 HISTORY CFLTFILE HISTORY COMPTAB HISTORY COMPTYP HISTORY CRCORR HISTORY CRMASK HISTORY CRPIX1 HISTORY CRPIX2 HISTORY CRRADIUS HISTORY CRREJTAB HISTORY CRSIGMAS HISTORY CRSPLIT HISTORY CRTHRESH HISTORY CRVAL1 HISTORY CRVAL2 HISTORY CTE_NAME HISTORY CTE_VER HISTORY CTEDIR HISTORY CTEIMAGE HISTORY CTYPE1 HISTORY CTYPE2 HISTORY D2IMFILE HISTORY DARKCORR HISTORY DARKFILE HISTORY DATE HISTORY DATE-OBS HISTORY DEC_APER HISTORY DEC_TARG HISTORY DETECTOR HISTORY DFLTFILE HISTORY DGEOFILE HISTORY DIRIMAGE HISTORY DQICORR HISTORY DRIZCORR HISTORY DRKCFILE HISTORY EQUINOX HISTORY ERRCNT HISTORY EXPEND HISTORY EXPFLAG HISTORY EXPNAME HISTORY EXPSCORR HISTORY EXPSTART HISTORY EXPTIME HISTORY EXTEND HISTORY FGSLOCK HISTORY FILENAME HISTORY FILETYPE HISTORY FILLCNT HISTORY FILTER1 HISTORY FILTER2 HISTORY FLASHCUR HISTORY FLASHDUR HISTORY FLASHSTA HISTORY FLATCORR HISTORY FLSHCORR HISTORY FLSHFILE HISTORY FW1ERROR HISTORY FW1OFFST HISTORY FW2ERROR HISTORY FW2OFFST HISTORY FWSERROR HISTORY FWSOFFST HISTORY GCOUNT HISTORY GLINCORR HISTORY GLOBLIM HISTORY GLOBRATE HISTORY GOODMAX HISTORY GOODMEAN HISTORY GOODMIN HISTORY GRAPHTAB HISTORY GYROMODE HISTORY IDCSCALE HISTORY IDCTAB HISTORY IDCTHETA HISTORY IDCV2REF HISTORY IDCV3REF HISTORY IMAGETYP HISTORY IMPHTTAB HISTORY INHERIT HISTORY INITGUES HISTORY INSTRUME HISTORY JWROTYPE HISTORY LFLGCORR HISTORY LFLTFILE HISTORY LINENUM HISTORY LOSTPIX HISTORY LRC_FAIL HISTORY LRC_XSTS HISTORY LRFWAVE HISTORY LTM1_1 HISTORY LTM2_2 HISTORY LTV1 HISTORY LTV2 HISTORY MDECODT1 HISTORY MDECODT2 HISTORY MDRIZSKY HISTORY MDRIZTAB HISTORY MEANBLEV HISTORY MEANDARK HISTORY MEANEXP HISTORY MEANFLSH HISTORY MLINTAB HISTORY MOFFSET1 HISTORY MOFFSET2 HISTORY MOONANGL HISTORY MTFLAG HISTORY NAXIS HISTORY NAXIS1 HISTORY NAXIS2 HISTORY NCOMBINE HISTORY NEXTEND HISTORY NGOODPIX HISTORY NPOLFILE HISTORY NRPTEXP HISTORY OBSMODE HISTORY OBSTYPE HISTORY OCD1_1 HISTORY OCD1_2 HISTORY OCD2_1 HISTORY OCD2_2 HISTORY OCRPIX1 HISTORY OCRPIX2 HISTORY OCRVAL1 HISTORY OCRVAL2 HISTORY OCTYPE1 HISTORY OCTYPE2 HISTORY OCX10 HISTORY OCX11 HISTORY OCY10 HISTORY OCY11 HISTORY ONAXIS1 HISTORY ONAXIS2 HISTORY OORIENTA HISTORY OPUS_VER HISTORY ORIENTAT HISTORY ORIGIN HISTORY OSCNTAB HISTORY P1_ANGLE HISTORY P1_CENTR HISTORY P1_FRAME HISTORY P1_LSPAC HISTORY P1_NPTS HISTORY P1_ORINT HISTORY P1_PSPAC HISTORY P1_PURPS HISTORY P1_SHAPE HISTORY PA_APER HISTORY PATTERN1 HISTORY PATTSTEP HISTORY PA_V3 HISTORY PCOUNT HISTORY PCTECORR HISTORY PCTEFRAC HISTORY PCTENSMD HISTORY PCTERNCL HISTORY PCTESHFT HISTORY PCTESMIT HISTORY PCTETAB HISTORY PFLTFILE HISTORY PHOTBW HISTORY PHOTCORR HISTORY PHOTFLAM HISTORY PHOTMODE HISTORY PHOTPLAM HISTORY PHOTTAB HISTORY PHOTZPT HISTORY PODPSFF HISTORY POSTARG1 HISTORY POSTARG2 HISTORY PRIMESI HISTORY PR_INV_F HISTORY PR_INV_L HISTORY PR_INV_M HISTORY PROCTIME HISTORY PROPAPER HISTORY PROPOSID HISTORY QUALCOM1 HISTORY QUALCOM2 HISTORY QUALCOM3 HISTORY QUALITY HISTORY RA_APER HISTORY RA_TARG HISTORY READNSEA HISTORY READNSEB HISTORY READNSEC HISTORY READNSED HISTORY REFFRAME HISTORY REJ_RATE HISTORY RPTCORR HISTORY SCALENSE HISTORY SCLAMP HISTORY SDQFLAGS HISTORY SHADCORR HISTORY SHADFILE HISTORY SHUTRPOS HISTORY SIMPLE HISTORY SIZAXIS1 HISTORY SIZAXIS2 HISTORY SKYSUB HISTORY SKYSUM HISTORY SNRMAX HISTORY SNRMEAN HISTORY SNRMIN HISTORY SOFTERRS HISTORY SPOTTAB HISTORY STATFLAG HISTORY STDCFFF HISTORY STDCFFP HISTORY SUBARRAY HISTORY SUN_ALT HISTORY SUNANGLE HISTORY TARGNAME HISTORY TDDALPHA HISTORY TDDBETA HISTORY TELESCOP HISTORY TIME-OBS HISTORY T_SGSTAR HISTORY VAFACTOR HISTORY WCSAXES HISTORY WCSCDATE HISTORY WFCMPRSD HISTORY WCSNAME HISTORY WRTERR HISTORY XTENSION HISTORY WCSNAMEO HISTORY WCSAXESO HISTORY LONPOLEO HISTORY LATPOLEO HISTORY RESTFRQO HISTORY RESTWAVO HISTORY CD1_1O HISTORY CD1_2O HISTORY CD2_1O HISTORY CD2_2O HISTORY CDELT1O HISTORY CDELT2O HISTORY CRPIX1O HISTORY CRPIX2O HISTORY CRVAL1O HISTORY CRVAL2O HISTORY CTYPE1O HISTORY CTYPE2O HISTORY CUNIT1O HISTORY CUNIT2O HISTORY APERTURE APERTURE multi HISTORY DETECTOR DETECTOR first HISTORY EXPEND EXPEND max HISTORY EXPSTART EXPSTART min HISTORY EXPTIME TEXPTIME sum HISTORY EXPTIME EXPTIME sum HISTORY FILTER1 FILTER1 multi HISTORY FILTER2 FILTER2 multi HISTORY GOODMAX GOODMAX max HISTORY GOODMEAN GOODMEAN mean HISTORY GOODMIN GOODMIN min HISTORY INHERIT INHERIT first # maintain IRAF compatibility HISTORY INSTRUME INSTRUME first HISTORY LRFWAVE LRFWAVE first HISTORY NCOMBINE NCOMBINE sum HISTORY MDRIZSKY MDRIZSKY mean HISTORY PHOTBW PHOTBW mean HISTORY PHOTFLAM PHOTFLAM mean HISTORY PHOTMODE PHOTMODE first HISTORY PHOTPLAM PHOTPLAM mean HISTORY PHOTZPT PHOTZPT mean HISTORY PROPOSID PROPOSID first HISTORY SNRMAX SNRMAX max HISTORY SNRMEAN SNRMEAN mean HISTORY SNRMIN SNRMIN min HISTORY TARGNAME TARGNAME first HISTORY TELESCOP TELESCOP first HISTORY WCSNAME WCSNAME first HISTORY ATODCORR ATODCORR multi HISTORY ATODGNA ATODGNA first HISTORY ATODGNB ATODGNB first HISTORY ATODGNC ATODGNC first HISTORY ATODGND ATODGND first HISTORY ATODTAB ATODTAB multi HISTORY BADINPDQ BADINPDQ sum HISTORY BIASCORR BIASCORR multi HISTORY BIASFILE BIASFILE multi HISTORY BLEVCORR BLEVCORR multi HISTORY BPIXTAB BPIXTAB multi HISTORY CCDCHIP CCDCHIP first HISTORY CCDGAIN CCDGAIN first HISTORY CCDOFSTA CCDOFSTA first HISTORY CCDOFSTB CCDOFSTB first HISTORY CCDOFSTC CCDOFSTC first HISTORY CCDOFSTD CCDOFSTD first HISTORY CCDTAB CCDTAB multi HISTORY CFLTFILE CFLTFILE multi HISTORY COMPTAB COMPTAB multi HISTORY CRCORR CRCORR multi HISTORY CRMASK CRMASK first HISTORY CRRADIUS CRRADIUS first HISTORY CRREJTAB CRREJTAB multi HISTORY CRSPLIT CRSPLIT first HISTORY CRTHRESH CRTHRESH first HISTORY CTEDIR CTEDIR multi HISTORY CTEIMAGE CTEIMAGE first HISTORY DARKCORR DARKCORR multi HISTORY DARKFILE DARKFILE multi HISTORY DATE-OBS DATE-OBS first HISTORY DEC_APER DEC_APER first HISTORY DFLTFILE DFLTFILE multi HISTORY DGEOFILE DGEOFILE multi HISTORY DIRIMAGE DIRIMAGE multi HISTORY DQICORR DQICORR multi HISTORY DRIZCORR DRIZCORR multi HISTORY EXPFLAG EXPFLAG multi HISTORY EXPSCORR EXPSCORR multi HISTORY FGSLOCK FGSLOCK multi HISTORY FLASHCUR FLASHCUR multi HISTORY FLASHDUR FLASHDUR first HISTORY FLASHSTA FLASHSTA first HISTORY FLATCORR FLATCORR multi HISTORY FLSHCORR FLSHCORR multi HISTORY FLSHFILE FLSHFILE multi HISTORY FW1ERROR FW1ERROR multi HISTORY FW1OFFST FW1OFFST first HISTORY FW2ERROR FW2ERROR multi HISTORY FW2OFFST FW2OFFST first HISTORY FWSERROR FWSERROR multi HISTORY FWSOFFST FWSOFFST first HISTORY GRAPHTAB GRAPHTAB multi HISTORY GYROMODE GYROMODE multi HISTORY IDCTAB IDCTAB multi HISTORY IMAGETYP IMAGETYP first HISTORY IMPHTTAB IMPHTTAB multi HISTORY LFLGCORR LFLGCORR multi HISTORY LFLTFILE LFLTFILE multi HISTORY LTM1_1 LTM1_1 float_one HISTORY LTM2_2 LTM2_2 float_one HISTORY MDRIZTAB MDRIZTAB multi HISTORY MEANEXP MEANEXP first HISTORY MOONANGL MOONANGL first HISTORY NRPTEXP NRPTEXP first HISTORY OBSMODE OBSMODE multi HISTORY OBSTYPE OBSTYPE first HISTORY OSCNTAB OSCNTAB multi HISTORY P1_ANGLE P1_ANGLE first HISTORY P1_CENTR P1_CENTR multi HISTORY P1_FRAME P1_FRAME multi HISTORY P1_LSPAC P1_LSPAC first HISTORY P1_NPTS P1_NPTS first HISTORY P1_ORINT P1_ORINT first HISTORY P1_PSPAC P1_PSPAC first HISTORY P1_PURPS P1_PURPS multi HISTORY P1_SHAPE P1_SHAPE multi HISTORY P2_ANGLE P2_ANGLE first HISTORY P2_CENTR P2_CENTR multi HISTORY P2_FRAME P2_FRAME multi HISTORY P2_LSPAC P2_LSPAC first HISTORY P2_NPTS P2_NPTS first HISTORY P2_ORINT P2_ORINT first HISTORY P2_PSPAC P2_PSPAC first HISTORY P2_PURPS P2_PURPS multi HISTORY P2_SHAPE P2_SHAPE multi HISTORY PATTERN1 PATTERN1 multi HISTORY PATTERN2 PATTERN2 multi HISTORY PATTSTEP PATTSTEP first HISTORY PHOTCORR PHOTCORR multi HISTORY PHOTTAB PHOTTAB multi HISTORY POSTARG1 POSTARG1 first HISTORY POSTARG2 POSTARG2 first HISTORY PRIMESI PRIMESI multi HISTORY PROPAPER PROPAPER multi HISTORY RA_APER RA_APER first HISTORY READNSEA READNSEA first HISTORY READNSEB READNSEB first HISTORY READNSEC READNSEC first HISTORY READNSED READNSED first HISTORY REJ_RATE REJ_RATE first HISTORY SCALENSE SCALENSE first HISTORY SCLAMP SCLAMP multi HISTORY SHADCORR SHADCORR multi HISTORY SHADFILE SHADFILE multi HISTORY SHUTRPOS SHUTRPOS multi HISTORY SKYSUB SKYSUB multi HISTORY SKYSUM SKYSUM sum HISTORY SPOTTAB SPOTTAB multi HISTORY SUBARRAY SUBARRAY first HISTORY SUNANGLE SUNANGLE first HISTORY SUN_ALT SUN_ALT first HISTORY WRTERR WRTERR multi HISTORY ------------------------------------------------------------ HISTORY End of rules... HISTORY ============================================================ HISTORY AstroDrizzle processing performed using: HISTORY AstroDrizzle Version 3.3.1 HISTORY PyFITS Version 4.3.1 HISTORY Numpy Version 1.21.2
1 Simple Image Polynomial (SIP) convention (Shupe et. al 2005). This convention has been in use for describing the geometry of Spitzer Space Telescope images, and it has become a FITS standard. Representing image distortion corrections using the SIP convention improves the handling of image combination and astrometric information.