SIRTF IRAC Test Data, Calibrated Image Data
HST WFPC2 PC1 data of R136 was used; image is 800 x 800 pixels
(files d2hk0317t1.fits (image) & q2hk0317t1.fits (mask))
- want 2 adjacent fields of view for the channel 1 & 3 data & the channel 2 & 4 data
for both the image and the mask files, take a section from the upper right hand
corner of the WFPC2 image
if channels 1 or 3,
take a 256 x 256 section whose lower left corner is x=325, y=315
if channels 2 or 4
take a 256 x 256 section whose lower left corner is x=325, y=170
modify calibrated image by adding bad pixels
o Use bad pixel info from the WFPC2 mask file that came with the image file.
- In that file, the questionable pixels flagged as "258" were made worse in this
image by multiplying them by 0.6. (This represents "responsivity unstable".)
- Take another set of bad pixels from the WFPC2 mask file, flagged as "2", and
modify those pixels of the calibrated image by multiplying them by 1.4
("responsivity too high").
o Dead pixels
Choose 0.1% of the pixels randomly (set them to "8" in the bad pixel map) &
modify those pixels in the calibrated image by setting them to "-1".
add noise to channel 3 & 4 images (to see if we can find it in our Level B
processes) for all pixels in the image, take a random number between -1 and 1 and
multiply it by 2, then add it to the value of the pixel in the image (only for
channel 3 & 4 data)