| Parasitic Light
QC1 database (advanced users):
In addition to the regular DARKs, there are also open-shutter DARKs (CATG = CALIB, TYPE = PARASITIC, TECH = IMAGE). They include, in addition to the CCD dark current, contribution from the camera enclosure. It most likely originates from Cerenkov radiation due to radioactive decay. These DARKs are regularly taken to monitor all kinds of parasitic light in the dome.
These data thus give detailed charateristics for all THREE UVES CCDs, one BLUE and two RED (UPPER and LOWER).
Parasitic Darks parameters
||QC1 database: table, name
| [calculated by QC procedure] || uves_dark..current_dark ||mean_dark, normalized to 3600 secs exposure time ||HC|| || [docuSys coming] |
| [calculated by QC procedure] || uves_dark..mean_raw ||mean value of raw frame ||CAL|| || [docuSys coming] |
| [calculated by QC procedure] || uves_dark..mean_dark ||mean value across master dark ||CAL|| || [docuSys coming] |
|*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter|
**There might be more than one.
These frames are taken approximately once per month, as a set of 3
consecutive exposures of 3600 secs each. These data are de-biased and
combined into a MASTER_DARK, in which the average dark level is
measured (in ADU/px/hr).
You can also see here
basic QC parameters related to detector properties (like median level,
ReadOut Noise, etc).
Scoring&thresholds Parasitic Darks parameters
The thresholds are set as an offset around the median.
The user manual gives an indication of the values. These are given in e-/pix/h (ADU/pix/h) at -120C:
The trending of the Parasitic Light DARK during the life time of the instrument is best be seen with the full history PDARK trending plots shown here: FULL DARK history.
Algorithm Parasitic Darks parameters
All the parameters are calculated by a QC script