MDM Trouble Report for 2006 Oct 16

Telescope: 2.4m
Observer(s): Prieto (OSU)
Instrument: CCDS

Problem(s) Encountered:
CCDS images still show organized readout pattern. Its like a sine-wave 
with  bright  (counts above average) and  dark  (counts below average).   
This is pretty bad because its a 5% effect in the bias (approx. 
+/- 10 counts in a ~190 counts bias) and it changes as a function 
of time, it can't be corrected with bias frames obtained right 
after the science frames!. 

Please take a look at three CCDS bias obtained right after 
a science exposure: 

/home/hiltner/data/bias1.fits 
/home/hiltner/data/bias2.fits 
/home/hiltner/data/bias3.fits 

For example, look at bias1 - bias2 = bias1_2.fits, its there.

I haven't done tests yet with the spectra of faint supernovae
but I would think this can affect the results (supernova spectra 
have broad features), although I'm not sure.  

------------------------------

Submitted on 2006 Oct 17 [6:18:42]