This page contains BADPIX masks for the WFI.
These BADPIX mask files contain 8 individual BADPIX files - one for each of the WFI chips.

NOTE: A detailed report on the creation of the BADPIX masks can be found here.
The following is a summary of the processes and the resulting BADPIX masks for WFI.

Program

I have written a PERL script ( mkBADPIX.pl ) which takes the raw data and outputs the tarred, gzipped badpixel files to go on the web.

Creation -- What mkBADPIX.pl does

They are created in the following way:

• Take: 5 Bias images, 5 Domeflats with low counts (~5000 counts), 5 Domeflats with high counts (~20,000 counts)
• Overscan and trim all images
• Zerocombine the Bias images
• Bias subtract the Domeflat images
• Flatcombine the domeflats with high counts - FLATHIGH
• Flatcombine the domeflats with low counts - FLATLOW
• mscarith FLATLOW.fits / FLATHIGH.fits FLATLHRATIO.fits
• mscsplit FLATLHRATIO.fits
• ccdmask FLATLHRATIOx.fits BADPIX5x.pl with the following parameters set:
  

                    Image Reduction and Analysis Facility
PACKAGE = ccdred
   TASK = ccdmask

image   =                       Input image
mask    =                       Output pixel mask
(ncmed  =                    7) Column box size for median level calculation
(nlmed  =                    7) Line box size for median level calculation
(ncsig  =                   15) Column box size for sigma calculation
(nlsig  =                   15) Line box size for sigma calculation
(lsigma =                  20.) Low clipping sigma
(hsigma =                  20.) High clipping sigma
(ngood  =                    5) Minimum column length of good pixel seqments
(linterp=                    2) Mask value for line interpolation 
(cinterp=                    3) Mask value for column interpolation 
(eqinter=                    2) Mask value for equal interpolation
(mode   =                   ql)

NEW BADPIX masks (sigma=20)

• Data taken March 12 2004 .
• Data taken May 29 2003 .

OLD BADPIX masks (made with a much lower sigma=5)

See here for the way the masks used to be created.

• Data taken November 2001 .
• Data taken February 2002.
• Data taken June 2002 .

How to use the BADPIX masks

The file you download has 8 badpix masks, one for each chip. They are labelled BADPIX5?.pl representing the official names of the 8 chips. These are NOT perl scripts (though the labelling is misleading). These are the files that you indicate in the FIXFILE keyword of CCDPROC . Simply enter the names of the badpix files there and run CCDPROC . That's all there is to it!