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GIRAFFE trending system: HISTORY plot
Last update: 2009-01-14T15:16:26 (UT)
same group: dark linearity&gain fp-noise contamination   correlations
close window history: 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024   HEALTH
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*Date on this monitor changes at 21:00 UT
Print: Information and research:
- png file - advanced studies: QC1 browser | QC1 plotter
- trending of linearity and gain here
Plot
?		 Symb
?		 Source
*		 Average ? Thresholds ? N_
data		 QC1
parameter		 Data
downloads		 Remarks
method value unit method value
1 oQC1DB none   ADU none   0 mean_signal this | last_yr | all new CCD (after 2008-04): mean image flat value in ADU, as function of exposure time
1 •QC1DB none   ADU none   137 mean_signal this | last_yr | all old CCD (before 2008-04): mean image flat value in ADU, as function of exposure time
3 •QC1DB none   ADU none   0 median_dit this | last_yr | all values from plot #1, normalized by exptime (only for new CCD)
4 oQC1DB none   ADU none   0 conad this | last_yr | all gain* values as function of mean flux in the image flats; only for new CCD)
(*note: the QC1 parameter is called conad by mistake, it should read gain)
*Data sources: QC1DB: QC1 database; LOCAL: local text file
This plot

This report hosts correlation plots for the monitoring of the GIRAFFE linearity and gain, derived from image flats. These data are taken about monthly. Since 2008-07, they are acquired with the common detector monitoring template and reduced with the corresponding common recipe.

Note the CCD upgrade between 2008-03 and 2008-05. Plots #3 and 4 are available for the new CCD only.

A sequence of image flats is exposed between 0.5 and 220 secs. Their average exposure level is plotted against the exposure time (box 1). The fitted function corresponds to mean = 245*exptime for the old CCD, and 195*exptime for the new CCD. In box 3, non-linear residuals are plotted vs. exposure time (new CCD only).

PLot 4 (for the new CCD only) shows the GAIN values plotted over exposure time. The asymptotic value for texp -> 0 is the true GAIN. The value stored in the file headers is indicated as "nominal".

Find the trending of non-linearity coefficient and gain here.  

General information

Click on any of the plots to see a close-up version. The latest date is indicated on top of the plot, data points belonging to that date are specially marked.

If configured,

  • statistical averages are indicated by a solid line, and thresholds by broken lines
  • outliers are marked by a red asterisk. They are defined as data points outside the threshold lines
  • "aliens" (= data points outside the plot Y limits) are marked by a red arrow (↑ or ↓)
  • you can download the data for each parameter set if the 'Data downloads' link shows up