[wiki:Background_Continuity Return] 

== March 5, 2012 ==

As discussed in the March 2 status, I've been looking into how the dark model may be introducing the gradients observed in the science data.  To see what (if any) functional dependence these gradients had, I selected dark frames used in the construction of the current dark model, and calculated the detproc (overscan corrected, no dark applied) and detresid (overscan and current dark model applied) images.  I used only XY67 in this study, as it has clear science image gradients, and was a useful test case.  For each variable that could influence the dark, I selected two exposures that spanned the range, while attempting to keep the remaining variables constant.

=== dateobs ===

|| exp_name || dateobs || exp_time || ccd_temp || detproc || detresid ||
|| o5605g0022d || 2011-02-13 || 10 || -78.455  || [[Image(o5605g0022d_detproc.png,200px)]] || [[Image(o5605g0022d_detresid.png,200px)]] ||
|| o5743g0645d || 2011-07-01 || 10 || -79.6983 || [[Image(o5743g0645d_detproc.png,200px)]] || [[Image(o5743g0645d_detresid.png,200px)]] ||

=== exp_time ===

|| exp_name || dateobs || exp_time || ccd_temp || detproc || detresid ||
|| o5641g0690d || 2011-03-21 || 0.001 || -87.2183 || [[Image(o5641g0690d_detproc.png,200px)]] || [[Image(o5641g0690d_detresid.png,200px)]] ||
|| o5638g0035d || 2011-03-18 || 300   || -87.0017 || [[Image(o5638g0035d_detproc.png,200px)]] || [[Image(o5638g0035d_detresid.png,200px)]] ||

=== ccd_temp ===

|| exp_name || dateobs || exp_time || ccd_temp || detproc || detresid ||
|| o5630g0494d || 2011-03-10 || 30 || -88.4883 || [[Image(o5630g0494d_detproc.png,200px)]] || [[Image(o5630g0494d_detresid.png,200px)]] ||
|| o5736g0606d || 2011-06-24 || 30 || -77.745 ||  [[Image(o5736g0606d_detproc.png,200px)]] || [[Image(o5736g0606d_detresid.png,200px)]] ||

=== ccd_temp2 ===

|| exp_name || dateobs || exp_time || ccd_temp || detproc || detresid ||
|| o5654g0593d || 2011-04-03 || 10 || -86.765 || [[Image(o5654g0593d_detproc.png,200px)]] || [[Image(o5654g0593d_detresid.png,200px)]] ||
|| o5612g0382d || 2011-02-20 || 10 || -72.1067 || [[Image(o5612g0382d_detproc.png,200px)]] || [[Image(o5612g0382d_detresid.png,200px)]] ||

=== 30s test ===

|| exp_name || dateobs || exp_time || ccd_temp || detproc || detresid ||
|| o5666g0013d || 2011-04-15 || 30 || -84.43 || [[Image(o5666g0013d_detproc.png,200px)]] || [[Image(o5666g0013d_detresid.png,200px)]] ||
|| o5666g0645d || 2011-04-15 || 30 || -84.37 || [[Image(o5666g0645d_detproc.png,200px)]] || [[Image(o5666g0645d_detresid.png,200px)]] ||