Dark level, Readout-noise and their time-variations
of GE1650


(measured by H.Watanabe on 13th Mar. 2007)


* A/D: 12 bit, BIN: 2x2, Exposure time: 80 ms, Frame Rate: 12 Hz, Gain: 0
* Continuous 16 frames were grabbed in 13 times at every 10 min.
* Total duration is 120 min.
* So, the number of all frames is 16x13 = 208 frames.
* Error bars stand for RMS of all pixels of the CCD-chip,
  that we consider the typical level of the readout-noise.




[results]
 * After about 40 min, dark-level becomes stable
   whose value is 26.6 DN (= 0.65 % of 12 bit FullWell).
   (FullWell = 20,000 e-)
 * The size of typical readout-noise is about 8.1 DN (= 0.20 % of 12 bit FullWell).





[Comparison between GE1650 and ORCA-AG]

Estimated sizes of noises of both cameras 
that are calculated from actually measured readout noises and dark levels.








Actual Ca K Line Profile obtained with GE1650 (on 2007/03/09) and ORCA-AG (on 2007/03/26),
on the only one line of the each CCD-chip.