Re: Last Night's Run

[Tom Droege <tdroege@veriomail.com>]

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.
> >