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. When new versions of the pipeline and/or calibration files are present, the archive automatically re-processes any affected images, ensuring that at any given time, users will always download the best version of an image.
Data from the Archive arrives as multi-extension FITS files that contain three main categories of extensions, 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.fitsfor 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.fitsanddrz.fits/drc.fitsfiles, as summarized below. For detailed information on drizzled data, please refer to the Drizzlepac Handbook. - For
flt.fits/flc.fitsimages: during 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.fitsimage 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.fitsimages: 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
Figure 2.1: Data Format for Calibrated and Drizzled ACS Modes
For calibrated science data, WFC1 (chip 1) corresponds to extension ['SCI',2] or [4]. Hubble Advanced Products (HAP) images now contain an additional variable number of extensions containing World Coordinate System (WCS) headerlets for various alignment solutions.
The number of headerlets may vary from image to image depending on what has been done to it.
Below is the header listing of a standard flc.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()
Python OUTPUT:
Filename: jcsz32diq_flc.fits No. Name Ver Type Cards Dimensions Format 0 PRIMARY 1 PrimaryHDU 326 () 1 SCI 1 ImageHDU 248 (4096, 2048) float32 2 ERR 1 ImageHDU 53 (4096, 2048) float32 3 DQ 1 ImageHDU 45 (4096, 2048) int16 4 SCI 2 ImageHDU 246 (4096, 2048) float32 5 ERR 2 ImageHDU 53 (4096, 2048) float32 6 DQ 2 ImageHDU 45 (4096, 2048) int16 7 D2IMARR 1 ImageHDU 16 (64, 32) float32 8 D2IMARR 2 ImageHDU 16 (64, 32) float32 9 D2IMARR 3 ImageHDU 16 (64, 32) float32 10 D2IMARR 4 ImageHDU 16 (64, 32) float32 11 WCSDVARR 1 ImageHDU 16 (64, 32) float32 12 WCSDVARR 2 ImageHDU 16 (64, 32) float32 13 WCSDVARR 3 ImageHDU 16 (64, 32) float32 14 WCSDVARR 4 ImageHDU 16 (64, 32) float32 15 HDRLET 1 NonstandardExtHDU 18 (8640,) 16 HDRLET 2 NonstandardExtHDU 26 (112320,) 17 WCSCORR 1 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 18 NonstandardExtHDU 26 (112320,) 19 HDRLET 4 NonstandardExtHDU 26 (112320,)
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()
Python OUTPUT:
Filename: jcsz32010_drc.fits No. Name Ver Type Cards Dimensions Format 0 PRIMARY 1 PrimaryHDU 876 () 1 SCI 1 ImageHDU 87 (4220, 4333) float32 2 WHT 1 ImageHDU 44 (4220, 4333) float32 3 CTX 1 ImageHDU 37 (4220, 4333) int32 4 HDRTAB 1 BinTableHDU 595 8R x 293C [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, 24A, 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, 12A, 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, 11A, 1A, D, D, D, D, K, 3A, L, L, 6A, L, D, D, 9A, D, D, 3A, 8A, 1A, D, K, D, L, 28A, L, 5A]
One can also look for a specific keyword in a specific extension, such as the gain value in the primary header here.
Python INPUT:
from astropy.io import fits
fits_image_filename = 'jcsz32010_drc.fits'
with fits.open(fits_image_filename) as hdul:
print(hdul[0].header['CCDGAIN'])
Python OUTPUT:
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 hdul:
hdr = hdul[0].header
hdr
Python OUTPUT:
SIMPLE = T / conforms to FITS standard
BITPIX = 8 / array data type
NAXIS = 0 / number of array dimensions
EXTEND = T
DATE = '2025-08-03' / date this file was written (yyyy-mm-dd)
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
BSIDEOPS= 'FALSE' / Post-2021-07-15 B-Side Operations Indicator
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= 1.2282231E+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= 'v0.4.47 ' / cloud infrastructure package version
AWSDPVER= 'v0.2.29 ' / cloud docker image version
CSYS_VER= '2025.3.1.7-alignmentmatches-py311' / calibration software system vers
/ 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$72m1821dj_ccd.fits' / CCD calibration parameters
ATODTAB = 'N/A ' / analog to digital correction file
OSCNTAB = 'jref$17717071j_osc.fits' / CCD overscan table
BIASFILE= 'jref$6641837qj_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$78f1840oj_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_1247.pmap'
CRDS_VER= '12.1.4, b11.4.0, 64d96076d89b32a5687a6b77bb910ab93b3a99b3'
UPWCSVER= '1.7.5 ' / Version of STWCS used to update the WCS
PYWCSVER= '7.0.1 ' / Version of Astropy used to update the WCS
HISTORY CCD parameters table:
HISTORY reference table jref$72m1821dj_ccd.fits
HISTORY inflight
HISTORY CCD table with updated readnoise values for CCDGAIN=2.-------------
HISTORY July 2009
HISTORY DQICORR complete ...
HISTORY values checked for saturation
HISTORY DQ array initialized ...
HISTORY reference table jref$25g1256nj_bpx.fits
HISTORY INFLIGHT 30/03/2002 30/05/2002
HISTORY FITS reference table for bad pixel locations on ACS WFC
HISTORY BIASCORR complete ...
HISTORY reference image jref$6641837qj_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 GROUND
HISTORY New OSCNTAB which includes entries for all subarrays.--------------
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$72m1821dj_ccd.fits
HISTORY inflight
HISTORY CCD table with updated readnoise values for CCDGAIN=2.-------------
HISTORY July 2009
HISTORY CTE_NAME Par/Serial PixelCTE 2023 CTE algorithm name
HISTORY CTE_VER 3.0 CTE algorithm version
HISTORY CORRTYPE parallel CTE correction type
HISTORY FIXROCR 1 fix readout cosmic rays
HISTORY PCTETRSH -1.000000000000E+01 CTE over subtraction threshold
HISTORY PCTEFRAC 9.445563835308E-01 CTE scaling factor
HISTORY CTEDATE0 5.233486000000E+04 Date of instrument installation
HISTORY CTEDATE1 5.771044601020E+04 Date of CTE model pinning
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 CORRTYPE serial - Amp C CTE correction type
HISTORY CTEDATE0 4.900000000000E+04 Date of instrument installation
HISTORY CTEDATE1 6.050000000000E+04 Date of CTE model pinning
HISTORY PCTETLEN 100 max length of CTE trail
HISTORY PCTENFOR 1 Number of iter in forward model
HISTORY PCTENPAR 1 Number of iter in parallel transfer
HISTORY CORRTYPE serial - Amp D CTE correction type
HISTORY CTEDATE0 4.900000000000E+04 Date of instrument installation
HISTORY CTEDATE1 6.050000000000E+04 Date of CTE model pinning
HISTORY PCTETLEN 100 max length of CTE trail
HISTORY PCTENFOR 1 Number of iter in forward model
HISTORY PCTENPAR 1 Number of iter in parallel transfer
HISTORY CORRTYPE serial - Amp A CTE correction type
HISTORY CTEDATE0 4.900000000000E+04 Date of instrument installation
HISTORY CTEDATE1 6.050000000000E+04 Date of CTE model pinning
HISTORY PCTETLEN 100 max length of CTE trail
HISTORY PCTENFOR 1 Number of iter in forward model
HISTORY PCTENPAR 1 Number of iter in parallel transfer
HISTORY CORRTYPE serial - Amp B CTE correction type
HISTORY CTEDATE0 4.900000000000E+04 Date of instrument installation
HISTORY CTEDATE1 6.050000000000E+04 Date of CTE model pinning
HISTORY PCTETLEN 100 max length of CTE trail
HISTORY PCTENFOR 1 Number of iter in forward model
HISTORY PCTENPAR 1 Number of iter in parallel transfer
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$8ch1518tj_cte.fits
HISTORY INFLIGHT 01/03/2002 22/07/2010
HISTORY Parameters needed for gen3 pixel-based CTE correction -----------
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/envs/linux/lib/python3.11/site-packages/fitsblender/acs_&'
CONTINUE 'header.rules&'
CONTINUE '' / Name of header kw rules file
NEXTEND = 4
FILENAME= 'jcsz32010_drc.fits'
PROD_VER= 'DrizzlePac 3.10.0'
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$72m1821dj_ccd.fits
HISTORY inflight
HISTORY CCD table with updated readnoise values for CCDGAIN=2.-------------
HISTORY July 2009
HISTORY DARKCORR complete ...
HISTORY reference image jref$9362035lj_dkc.fits
HISTORY INFLIGHT 13/01/2016 10/02/2016
HISTORY CTE corrected dark for WFC data taken after Jan 13 2016 01:33:37---
HISTORY FLATCORR complete ...
HISTORY reference image jref$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 INFLIGHT 18/04/2000 29/09/2020
HISTORY photometry keywords reference file---------------------------------
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 SKYCELL
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 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 SKYCELL SKYCELL first
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 3.10.0
HISTORY PyFITS Version 7.0.1
HISTORY Numpy Version 2.2.4
Figure 2.2: WFC apertures Compared with the V2/V3 Reference Frame
In pipeline data products, WFC2 is displayed below WFC1 (along the y-axis) and is therefore designated as extension 1. To display the science image for WFC1, the user must specify the FITS extension [4] or ['SCI',2]. The WFC1 error and data quality arrays are specified as extension [5] (or ['ERR',2]) and extension [6] (or ['DQ',2]), respectively. The readout amplifiers (A,B,C,D) are indicated on the figure. Refer back to Figure 2.1 for the full list of extensions by detector, noting that some additional variable number of astrometric headerlet extensions may now also be present for ACS/WFC Hubble Advanced Products (HAP) images.
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.