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NACO Quality control:
Lamp Flat



CONICA raw frames taken with the lamp flat recipe come in series of 6 frames in an alternating lamp=ON, lamp=OFF manner. Instrument related parameters are the camera, the filter and the read out mode. The lampflat recipe generates three QC parameters: GAIN, FixedPatternNoise and LampEfficiency. See the User Manual for details. Other quality checks are performed by post-pipeline processing scripts.

  • PRODUCT_PLOT. This means that for each lampflat pipeline product and its associated raw frames we create a plot with the most significant features.
  • PRODUCT DIFFERENCE FRAME. The visual check includes the product frame, the difference between the product to be checked and the last taken product with the same instrument settings (= last coherent frame), and the difference with the a reference frame, taken at the beginning of instrument operations; which will be updated from time to time (e.g. once a year or after major interventions).

  • QC1 PARAMETER CROSS CHECK. This means that selected QC1 parameters are compared with the most recently obtained corresponding QC1 parameters.

  • TRENDING. This means that we store all qc1 parameters and build Run Charts which simply show the parameter as a function of time over a larger time interval.

NACO product files follow a certain naming convention.


There follows for each lampflat product type a QC1 plot. The Figure caption is equal for all four plots.

Figure caption
The median (collapsed) column of the product and of the reference product; the column at X=500 of the product frame.The median (collapsed) row of the product at Y=500 and Y=600 of the product frame.Flux of the six raw input frames.
Zoomed: The median (collapsed) column of the product and of the reference product; the column at X=500 of the product frame. Median column, X=500 column, Y=500 row and Y=600 row of the (master-reference) frame.Histogram of the lamp flat product and of the reference product.





Difference frames are a quick look tool to visualize structural changes within the optical components, such as changes in the camera position, vignetting by the mask or large scale changes (e.g. particles in the optical path).



Trending describes the variation of a QC1 parameter within a large time range. We show a time range of 4 months and generate 4 trending plots a year. The following QC1 parameters are determined and trended.

  • LF_STD = flat lamp frame standard deviation as derived from the eclipse command stcube. Note that the J filter shows a larger STD than all other filters.

    LF_STD (gif | ps)

  • gain as delivered by the lampflat recipe of the pipeline.

    gain (gif | ps)

  • FPN = fixed pattern noise as delivered by the lamp flat recipe:

    FPN (gif | ps)

  • LampEff = flat lamp efficiency (lamp aging) as delivered by the lamp flat recipe:

    LampEff (gif | ps)





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