[KIDS] QC FRINGES: ReducedScienceFrames invalidated due to improved defringing

[Hugo Buddelmeijer]

Dear KiDS team,

Some positive notes about the defringing:
* The experimental residual fringe detection algorithm works well:
   it detected several ReducedScienceFrames with residual fringes [2].
* The worst of these (almost all) were accidentally defringed with
   the 'old' defringing method, using old FringeFrames.
* Therefore, we can conclude that the new defringing algorithm
   (introduced late January [1]) works quite well when used.
* The bad ReducedScienceFrames (25 tiles) have been invalidated and
   new FringeFrames are created for these nights.

Some action items about defringing:
* Observations that still have residual fringes after applying the
   new defringing method should be identified.
* Both the defringing algorithm and the residual fringe detection
   algorithm are 'confused' by the presence of large ghosts and bars.
* Detecting and flagging or correcting these artifacts seems to be
   the best way to improve the defringing. (Furthermore, these might
   cause larger errors in the photometry than the fringes do.)
* The new FringeFrames can show a gradient in the amplitude of the
   fringes. It might be worthwhile to investigate whether this is
   physical.

Greetings,
Hugo Buddelmeijer

[1] 
http://wiki.astro-wise.org/projects:kids:survey_task_teams:detector_calibration
[2] http://wiki.astro-wise.org/people:hb:fringedetectionkids05