Even more MDS testing!

(This page is linked from the other Durham testing pages Durham_MDS_Testing and Durham_MDS_Testing2 and Durham_MDS_Testing3)

Here we look at stacks from the ps1-md release on November 18th 2009.

Photometry

Shown is the SDSS comparison for PSF mags on the ps1-md MD08 skycell 041 i-band stack 30204 (left) and Heather's previous stack (29871) on the same cell. Blue points are SDSS classified stars. Both have nominally the same exposure time (equivalent to 41 240sec exposures) and we assume come from the same set of exposures. However, the seeing is 2.0" on 30204 but only 1.4" on 29871, and the zero points differ by about 0.4 mags (note: the zero point for 29871 has the expected value). Clearly there are problems with the stellar photometry being non-linear.