[ ESO ] La Silla

2p2-m Telescope CCDs
SciOp
The Dutch CCD



General Information

Currently, ESO CCD #33 is in use at the Dutch 90cm Telescope.

[*] Main Characteristics of ESO CCD #33
[*] Archived data from old short tests
* Derivatives
* Standard CCD Test
* Long CCD Test



Time Evolution

The below plot shows the variation of the bias level, standard light-source (note that often a beta-light is used which, due to radioactive decay, will fade. It is also possible that the phosphor can be poisoned, but our data show no evidence for such an effect), gain, read-out noise, shutter error, and linearity error as a function of time. The values for the bias, gain and read-out noise are plotted along with the associated measurement error. The blue dashed line in the plots shows the mean value of all the points, while the dotted blue line shows the standard deviation of this distribution. The blue and red points in the bottom plot show the maximum deviations in a positive and negative sense wrt the least-squares fit of the linearity data. Plotted vertically on the bottom of the graph is the date (dd/mm) on which the test was made.

[Click here to download ps file]

For printing, the above plot is also available in postscript format . The raw data can also be viewed in a tabular format.




Standard CCD Test

Below we show the most recent test.



  ***  MIDAS logfile (vers. 95NOV) *** Th, 18 Mar 1999   13:46:33   Page 1
 
 
  ***  MIDAS logfile (vers. 95NOV) *** Th, 18 Mar 1999   13:47:28   Page 2
 
     ========================================================== 
     SUMMARY STANDARD TEST CCD#33 TAKEN ON 990318 IN slow MODE 
     ========================================================== 
  
      BIAS 
      ==== 
  
      5 biases at start test: average = 262.42 stddev =   1.98 
  
      There were 0 hot pixels/columns detected 
  
  
      TRANSFER FUNCTION AND LINEARITY DATA 
      ==================================== 
  
  Table : Std_slow_33_990318 
 Sequence Exp_tim1  Med_cnt1  Med_cnt2  Variance  Frc_cnt1  Frc_cnt2  el_adu1  
 -------- --------- --------- --------- --------- --------- --------- ---------
        1      2.94    1981.8    1982.0     549.0      0.16      0.23      3.61
        2      5.88    3957.5    3957.1    1101.9     -0.10     -0.25      3.59
        3     11.77    7909.4    7908.8    2208.1     -0.31     -0.30      3.58
        4     17.65   11874.4   11875.0    3323.2     -0.21     -0.14      3.57
        5     26.46   17813.6   17822.3    4943.6     -0.15     -0.14      3.60
        6     35.29   23783.8   23789.0    6656.5     -0.05     -0.03      3.57
        7     44.10   29732.6   29737.3    8300.5     -0.02     -0.02      3.58
        8     58.80   39718.0   39723.0   11001.5      0.17      0.18      3.61
        9     73.50   49673.8   49671.2   13841.0      0.22      0.20      3.59
       10     88.20   59654.3   59648.9   16388.3      0.29      0.28      3.64
 -------- --------- --------- --------- --------- --------- --------- ---------
  
      Dynamic range explored: from 7179 to 216084 e- 
      Average count rate measured: 674 ADU/sec. 
  
      CONV. FACTOR AND RON 
      ==================== 
  
      C.Fact =   3.62 +/-   0.01 e-/ADU 
  
      RON    =   7.15 +/-   0.03 e- RMS 
  
  
      SHUTTER ERROR 
      ============= 
  
 Average shutter error derived from fractional count rate = -0.007 sec 
  
  
      LINEARITY ERROR 
      =============== 
  
 Average linearity error after shutter correct. = + 0.29/-0.31 % 
  
 These errors represent maximum deviation in % from the average 
 count rate after correction for shutter delay 

In addition, the previous standard tests are available. Click in the table below to access these files.

Standard Tests 1 2 3 4 5 6
981022.txt aver.ps cbias.ps hist.ps lin1.ps lin2.ps trans.ps
981031.txt aver.ps cbias.ps hist.ps lin1.ps lin2.ps trans.ps
981111.txt aver.ps cbias.ps hist.ps lin1.ps lin2.ps trans.ps
981121.txt aver.ps cbias.ps hist.ps lin1.ps lin2.ps trans.ps
981218.txt aver.ps cbias.ps hist.ps lin1.ps lin2.ps trans.ps
981229.txt aver.ps cbias.ps hist.ps lin1.ps lin2.ps trans.ps
990103.txt aver.ps cbias.ps hist.ps lin1.ps lin2.ps trans.ps
990113.txt aver.ps cbias.ps hist.ps lin1.ps lin2.ps trans.ps
990125.txt aver.ps cbias.ps hist.ps lin1.ps lin2.ps trans.ps
990204.txt aver.ps cbias.ps hist.ps lin1.ps lin2.ps trans.ps
990210.txt aver.ps cbias.ps hist.ps lin1.ps lin2.ps trans.ps
990224.txt aver.ps cbias.ps hist.ps lin1.ps lin2.ps trans.ps
990304.txt aver.ps cbias.ps hist.ps lin1.ps lin2.ps trans.ps
990310.txt aver.ps cbias.ps hist.ps lin1.ps lin2.ps trans.ps
990318.txt aver.ps cbias.ps hist.ps lin1.ps lin2.ps trans.ps

In the above table, the postscript files are:

Column
Number
Description
1 Average of the rows and cols. of the bias image
2 Combined bias frame of 5 bias images
3 Histogram of the bias image
4 Plots of exposure sequence, unedited transfer and raw linearity
5 Plots of filtered linearity and differential non-linearity in
6 Filtered transfer curves for both data sets

Note: filtered means that saturated images or deviating too much from the other data, if present, have been removed.




Long CCD Test

Below are the results of the long tests carried out by ODT. Be warned that these are large compressed tar files, and are of specialised interest. To download, press the shift key and click on the hypertext link with your middle mouse button.

Long Tests
CCD.33.970508.tar.gz
CCD.33.970714.tar.gz
CCD.33.970809.tar.gz
CCD.33.970930.tar.gz
CCD.33.980702.tar.gz


[Observing] [ESO La Silla]  [The 2p2 Team Home Page]  [ESO]  [Index]  [Search]  [Help]  [News]