Summary of MD03.refstack.20121101 (in process of running/updating)

Similar to the MD03.GR0 (MD.GR0) refstacks for the 2011/2012 season, these include recent improvement and input cuts to help constrain the convolved stacks as well. Because the refstack is made with reprocessed pixels, the refstack pixels will now have the ubercalibration.

MD03 observations started at end of October (last season started early November and went through March with a few z,y through mid-June, prior to that ran Oct. 2010 to May 2011).

Filter	N total	N FWHM<8 pixels	N (FWHM<8 pixels for 2011/2012
g	484	405	81
r	472	424	89
i	602	547	148
z	837	781	298
y	386	367	152

MD03.V3 Processing (chip->warp + refstack)

Exposure reprocessing was done for only a limited number (~150) of the best images from 2009-2011 (not 2010-2011 like MD10,01,02 before since g,r, and somewhat i-band all seems to have not a good seeing in 2011) to provide a balance of N input warps versus best seeing, excluding exposures with large background, low zeropoints and large elongation. Processing chip-warp and the refstack itself has the same label, data_group

• label: MD03.refstack.20121101 --> once set as active refstack for diffims, stack label will change to MD03.refstack, chip/cam/warp label will remain the same
• data_group: MD03.refstack.20121101

Histograms of the FWHM major and minor and elongation from camera stage value (full exposure) for the sample of reprocessed exposures (red) and used for refstack.20121101 (top blue) and used for refstack.2011 (bottom blue) in grizy order

Test stack (reftest) sample also made again for skycell.055 with different number of input warps.

• label: MD03.reftest.20121101
• data_group:
  • MD03.reftest.20121101.c#f<FWHM cut> where #=comparison run, <FWHM cut>=cut <fwhm_major from camProcessedExp x10>
  • MD03.reftest.20121101.all.<FWHM cut> where all means 2009+2010+2011 data possible, <FWHM cut>=cut <fwhm_major from camProcessedExp x10>
  • MD03.reftest.20121101.2011.<FWHM cut> where 2011 means 2011 data only, <FWHM cut>=cut <fwhm_major from camProcessedExp x10>

Summary comparison table with the approximate FWHM (major) as the PSF FWHM from a center field skycell (V3=055) after running psphot on the stacks.

version data_group (stack_id)	filter	center skycell input warps (rej)	center skycell FWHM (major, pixels)
new MD03.refstack.20121101	g
MD03.reftest.20121101.all.50	g
old MD03.refstack.20111010	g
new MD03.refstack.20121101	r
MD03.reftest.20121101.all.45	r
old MD03.refstack.20111010	r
new MD03.refstack.20121101	i
MD03.reftest.20121101.all.41	i
old MD03.refstack.20111010	i
new MD03.refstack.20121101	z
MD03.reftest.20121101.all.39	z
old MD03.refstack.20111010	z
new MD03.refstack.20121101	y
MD03.reftest.20121101.all.40	y
old MD03.refstack.20111010	y

As before, the FWHM_MAJOR with the central skycell can be variable and more so with largely different input sets. Comparison with the psf_major/minor maps are more useful between refstack versions.

Problems

• generally edge skycells have issues, need better containment of those still.
• some convolved stacks have strange PSF -- reprocessed using DEEP_STACK config with lighter input restrictions so may not have best FWHM, but 99% on the edge of field so won't anyways?
  • g:
  • r:
  • i:
  • z:
  • y:
• bad cell arc in primarily skycell.036,033,024,025,026,047 y-band from ota14, cell 31 ??

• poor/bad cell arc in primarily skycell.054 g-band (and less so in other filters) from ota43, cell 54? see MD10.refstack.20120705 ??
• misc ghosts in g-band ??

Refstack Summary

Refstacks run through the staticsky (single filter mode so basic psphot with deteff measurements) and skycal stage on the unconvolved stacks to make the map plots (full 5 filter version still having occasional faults to work through):

• label: MD03.refstack.20121101, MD03.refstack.20121101
• data_group: MD03.refstack.20121101.1x2012, MD03.refstack.20120927.1x20120805.cal2012xxxxx

Source photometry psf_major,_minor maps (grizy):

Magnitude of sources@5-sigma maps (grizy):

Detection efficiency magnitude @50% recovery (500 fakes, grizy):