Yet more MDS testing!

These are outstanding issues from the MD08 stacks provided by Paul and Heather:

Background problems due to removing the correlated read noise

The above is a portion of MD08.skycell.041.stk.29871, Heather's stack of the 41 best i-band images using the latest version of IPP. The vertical dark streaking around all the bright images is due to the background polynomial fits used in removing the correlated read noise. The displayed image is about 12 arcmin from top to bottom.

Clipping of stars at the stacking stage

Above is one of Paul's nightly stacks of 8 i-band images, MD08.skycell.041.stk.25532 . This is the best seeing (~1.0" FWHM) of any of them. Masked pixels are shown in red. Note how most of the centres of the stars are masked. This masking happens at the stacking stage, and is not in the warps. The scale here is about 6 arcmin from top to bottom.

Another of Paul's nightly stacks of 8 i-band images, MD08.skycell.041.stk.26482 . The seeing is worse here (~1.4" FWHM) but the clipping is also worse. There are virtually no unmasked stars on this image, and several galaxies are also masked.