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Calibration Database System

WFPC2 Reference File Tables

Reference files used by the WFPC2 calibration pipeline (CALWP2) have been updated on a regular basis. All available reference files can be retrieved from the HST archive, or downloaded directly from the uref directory. If you choose to access the files via this ftp server, keep in mind that there is a known bug in trying to access files via ftp server using Safari. The recommended browser is Firefox.

If you would like to receive an e-mail every time a new WFP2 reference file is delivered and the database is updated, you can subscribe to the wf2_reffiles_upd mailing list. To subscribe to this list, send an e-mail to MajorDomo @ with the following in the body of the message:
subscribe wf2_reffiles_upd your_address .

Each reference file has listed along with it the suggested "use after" date, the camera used and where necessary, the shutter, filter numbers, atodgain, clock, and/or filternames are given as well. The dataname in the table is the rootname of the reference file; the file extensions follow the convention outlined in ICD 47 (Post Observation Data Processing System to Calibration Data Base System Interface Control Document, Chapter 7):
 ASCII header   Binary data   type of reference file 
  ------------   -----------   ----------------------
    .r0h           .r0d        static mask
    .r1h           .r1d        analog to digital converter correction
                               lookup table

    .r2h           .r2d        bias frame
    .b2h           .b2d        bias data quality file

    .r3h           .r3d        dark frame
    .b3h           .b3d        dark data quality file

    .r4h           .r4d        flatfield 
    .b4h           .b4d        flatfield data quality file

    .r5h           .r5d        shutter shading correction

    .r6h           .r6d        (non-pipline) delta darks and correction flatfields
    .r7h           .r7d        WF4 anomaly correction
    .r9h           .r9d        pixel area correction file

Pipeline Reference Files Extension Header Keyword Mode
Mask Tables
Flags defects in the CCD that degrade pixel performance but are stable over time. More...
A to D Tables
Corrects value of each pixel for the analog-to-digital conversion error. More...
Bias Images
Used to remove any position-dependent bias pattern remaining after the pedestal level is removed. More...
Dark Images
Used to detect CCD counts caused by thermal processes at the interfaces between the silicon and oxide layers, as well as charged particle and secondary radiation events. More...
Flatfield Images
Corrects for the large-scale illumination pattern and the pixel-to-pixel response function. More...
Shutter Shading Images
Corrects the effects of the shutter motion in short (<10 seconds) exposures. More...
WF4 Correction Tables
Used to correct low CCD bias levels and lowered count levels (low CCD gain) on the WF4 detector. More...
.r7h/d WF4TFILE N/A
Distortion Correction Table
Used in drizzling WFPC2 images. Contains the best distortion models for all four chips. More...
Inter-chip Offsets Table
Used in conjunction with the IDC table; contains the secular relative orientations and positions of the chips. More...
34 Row Displacement Correction File
Corrects for the reduced sensitivity seen in approximately every 34th row in the detectors. More...

Non-pipeline Reference Files Extension Header Keyword Mode
IDT Superbias Files
Early bias files created by the IDT to remove any position-dependent bias pattern remaining after the pedestal level is removed. More...
IDT Superdark Files
Early dark files created by the IDT; behave like regular pipeline darks, may have better noise characteristics. More...
IDT Deltadark Files
Used with IDT Superdark and Superbias files to remove hot pixels in early WFPC2 data. More...
Correction Flats from Erich Karkoschka
Correction flat to be multiplied by the 'previous' flatfield to produce a less noisy revised flatfield. More...
.r6h/d --- FULL
Pixel Area Correction File
Used to restore the proper total counts of the target. More...
.r9h/d --- FULL