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Calbration Reference Data System
ACS Reference Files

ACS Reference File Tables

Reference files used by the ACS calibration pipeline (CALACS and Astrodrizzle) are updated on a regular basis. Current reference files can be retrieved from the HST archive, or downloaded directly from the jref directory. Note that FTP access is browser dependent: Safari does not work; Firefox or Chrome may or may not work depending on the Operating System. If you cannot download the files via Firefox or Chrome, you can try using a standalone FTP tool or accessing the ftp site directly (ftp ftp.stsci.edu) with 'anonymous' (without quotes) as your username and your email address as your password.

If you would like to receive an e-mail every time a new ACS reference file is delivered and the database is updated, you can subscribe to the acs_reffiles_upd mailing list. To subscribe to this list, send an e-mail to MajorDomo @ stsci.edu with the following in the body of the message:
subscribe acs_reffiles_upd your_address .

New tools for exploring ACS Reference Files are now available at https:/hst-crds.stsci.edu. To get a listing of the reference files you're interested in, click on 'acs' then select the filetype. Use the names below in the Header Keyword column as a guide.

Reference File Type Extension Header Keyword Camera
ACS A-to-D Tables
Analog to Digital conversion information. More...
a2d ATODTAB WFC and HRC
ACS Bad Pixel Table
Flag "permanently" bad pixels in the data quality (DQ) arrays of ACS images. More...
bpx BPIXTAB All
ACS Bias Reference Images
Superbias images for subtracting bias structure. More...
bia BIASFILE WFC and HRC
ACS CCD Tables
Converts commanded properties to calibrated values for each CCD amplifier. More...
ccd CCDTAB WFC and HRC
ACS CCD Overscan Table
Describes CCD overscan regions used to measure bias level. More...
osc OSCNTAB WFC and HRC
ACS Column Correction File (D2IMFILE)
File which describes the column/row correction as a 1-D correction. More...
d2i D2IMFILE WFC
ACS Cosmic Ray Rejection Tables
Parameters for rejecting cosmic rays from CR-SPLIT images. More...
crr CRREJTAB WFC and HRC
ACS CTE Corrected Darks
De-trailed reference images used for dark current subtraction and hot pixel flagging and correction for use with the pixel-based CTE correction step within CALACS. More...
dkc DRKCFILE WFC
ACS Dark Files
Reference images for dark current subtraction, including hot pixel correction and flagging. More...
drk DARKFILE All
ACS Distortion Correction Tables
Parameters for geometric distortion correction. More...
idc IDCTAB All
ACS Flat Field Files
Pixel-to-pixel correction file containing small scale variations. More...
pfl PFLTFILE All
ACS HRC Coronagraphic Spot Table
Position of the coronagraphic spot versus time. More...
csp SPOTTAB HRC
ACS HRC Coronagraphic Spot Flat Field Files
Vignetting patterns of the occulting spots. More...
cfl CFLTFILE HRC
ACS MultiDrizzle Parameter Tables
Parameters for combining and cleaning associated datasets. More...
mdz MDRIZTAB All
ACS Non-polynomial Offset Files (NPOLFILE)
Files which, along with D2IMFILE, replace DGEOFILE with a 65x33 table of non-polynomial corrections for X and Y for each chip. More...
npl NPOLFILE All
ACS Photometry Keyword Tables
Replaces calls to SYNPHOT for generating photometry keywords with pre-computed values. More...
imp IMPHTTAB All
ACS Pixel-Based CTE Correction Table
Parameters used in generating the CTE corrections in WFC Data. More...
cte PCTETAB WFC
ACS Post-Flash Reference Images
Full frame reference image for subtracting ACS/WFC post-flash. More...
fls FLSHFILE WFC
ACS SBC Linearity Table
Parameters for determining linearity in MAMA images. More...
lin MLINTAB SBC

ACS Non-Pipeline Reference Files

Reference File Type Extension Header Keyword Camera
ACS HRC Earth Flat Reference Files
Flats for large, diffuse objects. More...
--- --- HRC