Summary of MD02.refstack.20120827

Similar to the MD02.GR0 (MD.GR0#MD02.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.

MD02 observations started Sept. 27 (last season started mid-Sept. and ended end of February).

Filter N total N (FWHM<8 pixels)
g 331 260
r 327 281
i 427 386
z 509 483
y 386 340

MD02.V3 Processing (chip->warp + refstack)

Exposure reprocessing was done for only a limited number (~150) of the best images from 2010+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: MD02.refstack.20120927 --> MD02.refstack for stack label will change once set as active refstack for diffims, chip/cam/warp label will remain the same
  • data_group: MD02.refstack.20120927

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.20120927 (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. Found skycell.055 may not be a good indicator of FWHM with different number of inputs, also did sample for skycell.033.

  • label: MD02.reftest.20120927
  • data_group:
    • MD02.reftest.20120927.c#f<FWHM cut> where #=comparison run, <FWHM cut>=cut <fwhm_major from camProcessedExp x10>
    • MD02.reftest.20120927.all.<FWHM cut> where all means 2009+2010+2011 data possible, <FWHM cut>=cut <fwhm_major from camProcessedExp x10>
    • MD02.reftest.20120927.2011.<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 filter center skycell.055 input warps (rej) center skycell.055 FWHM (major pixels) skycell.033 input warps (rej) skycell.033 FWHM (major pixels)
new MD02.refstack.20120927 g 78(29) 5.52 78(15) 4.50
MD02.reftest.20120927.all.55 g 79(31) 5.52 79(24) 4.49
MD02.reftest.20120927.2011.55 g 41(15) 5.36 41(8) 4.47
MD02.reftest.20120927.c1f52 g 37(10) 5.56 37(12) 4.37
MD02.reftest.20120927.c1f54 g 61(20) 5.49 61(19) 4.43
MD02.reftest.20120927.c1f61 g 93(37) 5.54 93(24) 4.54
MD02.reftest.20120927.c1f62 g 104(47) 5.33 104(28) 4.58
old MD02.refstack.20110907 g 64(6) 5.28 64(4) 4.68
new MD02.refstack.20120927 r 85(18) 4.46 85(20) 4.41
MD02.reftest.20120927.all.49 r 88(20) 4.96 88(24) 4.06
MD02.reftest.20120927.2011.49 r 50(15) 4,91 50(12) 4.07
MD02.reftest.20120927.c1f 45 r 36(8) 4.79 36(7) 3.97
MD02.reftest.20120927.c1f47 r 63(11) 4.87 63(17) 4.01
MD02.reftest.20120927.c1f51 r 89(20) 4.93 89(20) 4.09
MD02.reftest.20120927.c1f58 r 118(34) 5.02 118(37) 4.15
old MD02.refstack.20110907 r 63(6) 4.6 63(5) 4.19
new MD02.refstack.20120927 i 86(22) 4.41 86(19) 3.89
MD02.reftest.20120927.all.45 i 89(21) 4.31 89(23) 3.81
MD02.reftest.20120927.2011.45 i 40(12) 3.71 40(10) 3.75
MD02.reftest.20120927.c1f41 i 34(7) 4.26 34(9) 3.70
MD02.reftest.20120927.c1f43 i 54(9) 4.33 54(13) 3.80
MD02.reftest.20120927.c1f48 i 92(27) 4.43 92(27) 3.88
MD02.reftest.20120927.c1f52 i 121(23) 4.47 121(35) 3.96
old MD02.refstack.20110907 i 61(2) 4.0 61(1) 3.99
new MD02.refstack.20120927 z 92(22) 3.85 92(26) 3.65
MD02.reftest.20120927.all.41 z 91(28) 3.78 91(23) 3.63
MD02.reftest.20120927.2011.41 z 40(10) 3.70 40(8) 3.67
MD02.reftest.20120927.c1f38 z 25(7) 3.54 25(5) 3.37
MD02.reftest.20120927.c1f40 z 58(20) 3.87 58(12) 3.55
MD02.reftest.20120927.c1f42 z 92(22) 3.85 92(26) 3.64
MD02.reftest.20120927.c1f45 z 116(27) 3.90 116(22) 3.70
old MD02.refstack.20110907 z 67(5) 3.6 67(2) 3.75
new MD02.refstack.20120927 y 86(25) 3.62 86(17) 3.47
MD02.reftest.20120927.all.41 y 95(29) 3.60 95(18) 3.48
MD02.reftest.20120927.2011.41 y 86(16) 3.60 86(27) 3.44
MD02.reftest.20120927.c1f38 y 35(5) 3.52 35(8) 3.35
MD02.reftest.20120927.c1f39 y 61(11) 3.57 61(8) 3.43
MD02.reftest.20120927.c1f42 y 96(21) 3.62 96(23) 3.51
MD02.reftest.20120927.c1f46 y 118(25) 3.64 118(38) 3.51
old MD02.refstack.20110907 y 58(3) 4.04 58(2) 4.38

The center skycell often has a problem with worse seeing so added skycell.033 for comparison. Overall very little improvement in FWHM is possible (~0.2 pixels with minimum number of inputs as with other fields), but now depth is similar with other MD. Even worse, the FWHM_MAJOR can be unstable/variable on similar, repeated runs and should probably use IQ_FW1 as noted before.. also see the full field map below with comparison to the previous MD02 set.

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 will be poor anyways.
    • g: 012,017,061,071,082,087
    • r: 012,021,031,071,087
    • i: 017,071,078,087
    • z: 017
    • y: 017,071,087
  • bad cell arc in primarily skycell.036,033,024,025,026,047 y-band from ota14, cell 31 seen in MD01 as well. see MD01.refstack.20120803
  • poor/bad cell arc in primarily skycell.054,044 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:

  • label: MD02.refstack.20120927, MD02.refstack.20120927
  • data_group: MD02.refstack.20120927.1x20121005, MD02.refstack.20120927.1x20121005.cal20121005

A mess of previous runs were made including a full 5 filter psphotStack run, but some skycells have been swapped and is not entirely valid. The skycal stage also had to be modified after a fix to getstar and likely needs to be further tuned properly. A full stack photometry rerun will need to be made in the future.

Source photometry psf_major,_minor maps (grizy):

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

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

Attachments