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Quality Control and
Data Processing

CAL | HC | refs | QC
Trending & QC1
OmegaCAM ...
QC links:
OMEGACAM: Quick_check dome flats monitoring
quick-check dome level (lamp 1)
quick-check dome rms (lamp 1)
dome lamp flux per detector, a (lamp 1, ESO_CCD_65-80)
dome lamp flux per detector, b (lamp 1, ESO_CCD_81-96)
quick-check dome level (lamp 2)
quick-check dome rms (lamp 2)
dome lamp flux per detector, a (lamp 2, ESO_CCD_65-80)
dome lamp flux per detector, b (lamp 2, ESO_CCD_81-96)
quick-check dome level for selected detectors
QC1 database (advanced users): browse | plot

During normal VST/OmegaCAM operations a single, quick-check, DOME flat frame is taken to test the health of the instrument and the dome flat lamp. Most frequently, the quick-check dome flat is made using the r_SDSS filter and dome flat lamp1 (FFLS1). The pipeline applies a bias-correction, trims the images, and creates a table with frame statistics (mean, median, and standard deviation) for each detector.

The pipeline creates one output fits table from its quick-check dome flat recipe (omega_qcheck): OC_MLIF_<DATE>_1_1_normal_normal_<FILTER>.fits.

DOME Flat Level


FITS key QC1 database: table, name definition class* HC_plot** more docu
QC.QUICK.CHECK.MEDIAN omegacam_qcheck..qc_qcheck_median median counts in quick check dome flat (ADU) HC [docuSys coming]
QC.QUICK.CHECK.STDEV omegacam_qcheck..qc_qcheck_std standard deviation of quick check dome flat (ADU)HC [docuSys coming]
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter
**There might be more than one.

The QC1 health check plots for the RAW OmegaCAM dome flats are divided into 5 separate linked pages, each monitoring the flux level and rms with two dome flat lamps (FFLS1 and FFLS2 as read from the header keywords: INS.LAMP1.ID or INS.LAMP2.ID), and a detailed look at the flux level of six detectors.


For each dome flat lamp (FFLS1 or FFLS2) following parameters are monitored:

  • median flux level averaged over all 32 detectors (ADU)
  • median flux level for each detector (ADU)
  • score outliers
  • standard deviation over all 32 detectors (ADU)
  • standard deviation for each detector (ADU)
  • score outliers
  • normalized dome flat's lamp flux (both LAMP1.ID=FFLS1 and LAMP2.ID=FFLS2) per individual detector
  • a detailed (normalized) flux level for the less stable detectors ESO_CCD_#82, #87, and #88 as compared to the more stable detectors #89, #73, and #80

Scoring&thresholds DOME Flat Level

The median flux level and standard deviation averaged over all CCDs is scored loosely with static thresholds.


Date event
2014-01-13 Main dome flat lamp FFLS1 (lamp1) showed failing trend. Decision was taken to swap the role of the lamps and treat the FFLS2 (lamp2) as the main one. HealthCheck plots for "dome:quick_check" were reorganized accordingly. Later it became clear that the decrease in flux was due to installation of the baffling system on 2014-01-08 and further on 2014-04-06.
2014-04-25 Dome flat lamp FFLS1 (lamp1) again considered as the main lamp used for monitoring. HealthCheck plots for "dome:quick_check" were reorganized accordingly.
2018-08-18 CCD_75 has been failing over the last several days, replaced (PPRS-073742)

Algorithm DOME Flat Level

The median level and standard deviation of the quick-check dome flat frame is calculated for each extension (ADU).

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