= Summary = 
[[PageOutline]]

A gallery of diffim issues with PS1/GPC1 data prompted by Steve Hartung visit the week of Feb. 25, 2013 demonstrating/testing his method of ''Image subtraction noise reduction using point spread function cross-correlation''  [http://arxiv.org/abs/1301.1413].



= warp-warp =
Larry has provided a sample of exposures with known movers and varying diffim quality

== initial sample ==

Typical diffim for brighter and fainter source with full skycell

{{{
(128641)   o6326g0262o  139.858986755327  12.2168530604844  w          19.2427
(128641)   o6326g0283o  139.855172511159  12.218349817782   w          19.1446
RINGS.V3	skycell.1624.003	948.86	3439.24
--> quick scan see ~8 pairs from ~18-21
}}}
 * data test sample  /data/ipp058.0/mhuber/hartung_diffsample130226/o6326g0262o_o6326g0283o_skycell.1624.003


{{{
(298784)   o6326g0262o  140.518212856407  11.8433721460007  w          21.4309
(298784)   o6326g0283o  140.514364299835  11.844551426709   w          21.2395
RINGS.V3	skycell.1536.097	3579.29	3743.84
--> quick scan only see ~5 pairs and typically fainter
}}}

 * data test sample /data/ipp058.0/mhuber/hartung_diffsample130226/o6326g0262o_o6326g0283o_skycell.1536.097
== more difficult sample ==
Larry suggested ones of poorer quality, but <50% filled skycells (edge chips, which ones?)

{{{
OBJ_NAME  EXP_NAME    RA_DEG     DEC_DEG
2006RA71  o6326g0256o 138.031704 12.026011
2006RA71  o6326g0277o 138.028458 12.026909
--> RINGS.V3	skycell.1624.007	3644.78	701.58

| diff_id | warp_id | warp1  | warp2  | stack1 | stack2 | skycell_id       | data_group   |
|  374871 |  705594 | 705594 | 705637 |   NULL |   NULL | skycell.1624.007 | OSS.20130203 | 

}}}

[[Image(wwdiff_374871_skycell.1624.007.jpg,300px)]] 

 * no logfile in PSS bundles now so find at neb://stsci03.2/gpc1/OSS.nt/2013/02/03/RINGS.V3/skycell.1624.007/RINGS.V3.skycell.1624.007.dif.374871.log.bz2
 * data test sample /data/ipp058.0/mhuber/hartung_poordiffwarp130228/warpwarpdiff_374871_skycell.1624.007



{{{
OBJ_NAME  EXP_NAME    RA_DEG     DEC_DEG
2011SV179 o6326g0265o 141.107388 12.550592
2011SV179 o6326g0286o 141.103729 12.551618
--> RINGS.V3	skycell.1624.010	687.24	2568.08
| diff_id | warp_id | warp1  | warp2  | stack1 | stack2 | skycell_id       | data_group   |
|  374880 |  705625 | 705625 | 705646 |   NULL |   NULL | skycell.1624.010 | OSS.20130203 | 

}}}

[[Image(wwdiff_374880_skycell.1624.010.jpg,300px)]] 

 * logfile neb://stsci04.2/gpc1/OSS.nt/2013/02/03/RINGS.V3/skycell.1624.010/RINGS.V3.skycell.1624.010.dif.374880.log.bz2
 * data test sample /data/ipp058.0/mhuber/hartung_poordiffwarp130228/warpwarpdiff_374880_skycell.1624.010




= warp-stack =



= stack-stack = 
Example of common excess residuals as detections

{{{
| diff_id | skycell_id  | warp1 | stack1  | warp2 | stack2  | tess_id | diff_skyfile_id |
|  381715 | skycell.035 |  NULL | 2021020 |  NULL | 1878199 | MD04.V3 |        23371956 | 

      PHOTCODE is GPC1.i.SkyChip
      Input FWHM: 4.874815
      Reference FWHM: 3.570664
}}}
 * logfile neb://stsci01.2/gpc1/MD04.nightlyscience/2013/02/14/MD04.V3/skycell.035/MD04.V3.skycell.035.SS.dif.381715.log.bzip2
 * data sample /data/ipp058.0/mhuber/hartung_diffsample130226/stackstackdiff_381715_skycell.035


Poor convolution
{{{

      Input FWHM: 9.706131
      Reference FWHM: 3.729399
}}}
 * logfile neb://stsci08.1/gpc1/MD09.nightlyscience/2012/11/08/MD09.V3/skycell.055/MD09.V3.skycell.055.SS.dif.340080.log.bzip2
 * data sample /data/ipp058.0/mhuber/testppsun130225_340081_20121108md09poor