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Re: Last Night's Run




tom

i believe it is recommended that one take bias and dark frames at
different temperatures so that one knows what the system is like
. .  maybe a few at each temp just to make certain it is within a decent
sigma :]]]]]  better confidence level this way :]]]

keep with it, you are heading in the right direction, it is just a long
row to hoe

best

jamie


On Mon, 14 May 2001, Tom Droege wrote:

> Jure and all,
> 
> The plan is to take one bias frame at the start of each run.  This would 
> normally be done after the temperature had stabilized.   By starting with a 
> bias and a dark, the present program can use dusk time that is otherwise 
> useless.  The bias frame now includes a temperature.  The bias level will 
> wander around with the ambient temperature though the sigma should be 
> pretty constant.  The bias level shift will be of order the noise level, I 
> think.  When I get enough of this data I will encourage someone to plot the 
> bias level vs the available temperatures.  I expect to see about 6 ADU 
> counts per C ambient shift.  This is just 100 parts per million resistor 
> change and the 16 bit ADC.
> 
> Tom Droege
> 
> At 08:25 PM 5/14/01 +0200, you wrote:
> >Tom
> >
> >I think it can be very useful to have this bias frame.  But, since it is not
> >really necessary to make bias frames at night, you may just make a 
> >collection of
> >biases (and darks, for that matter) before or after you start imaging of the
> >sky.  For the statistical reasons, it is better to have a 
> >larger  collection of
> >these files and then make some sort of average.  Maybe one CDROM dedicated to
> >calibration images (bias and dark) would be in place, unless you have wildly
> >unstable cooling and read-out electronics.
> >
> >                                                 regards
> >                                                 Jure Skvarc
> >
> >Tom Droege wrote:
> > >
> > > Last night I got another run to add to disk set 18.  Jure, you will be glad
> > > to know that this one has a bias run at the beginning.  I will now keep
> > > running with this format.
> > >
> 
>