| reset level
| reset rms
| differential rms
QC1 database (advanced users):
The Daily Health Check templates for technical calibrations acquire each
day reset frames of the following (only) setup:
- NCORRS=Uncorr, NDIT=1, DIT=1.001100 sec
where 1.001100 is the MINDIT, the minimum possible DIT that can be
achieved with the currently configured read speed. RESET calibrations are
technical calibrations, they are not used to calibrate other calibrations
or science date. A raw DARK frame (the read mode is double correlated)
is a result of a reset-read-read sequence, where the first read result
is internally subtracted from the second read result and the reset level
cancels out. A raw RESET frame (the read mode is uncorrelated) is a
result of a reset-read sequence which shows the reset level. No other
calibrations use DET.NCORRS=Uncorr, only the technical RESET calibrations.
||QC1 database: table, name
| QC.RESETMED || vircam_reset..qc_reset_med ||HC|| || [docuSys coming] |
| QC.RESETRMS || vircam_reset..qc_reset_rms ||HC|| || [docuSys coming] |
| QC.RESETDIFFRMS || vircam_reset..qc_resetdiff_rms ||rms of reset difference frame ||ENG|| || [docuSys coming] |
|*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter|
**There might be more than one.
- The QC.RESETMED is the median of the master reset frame (= average of 5 raw bias frames).
- The QC.RESETRMS is the RMS over all pixel of the master bias product.
- A reference reset frame is maintained and updated after detector interventions. The QC.RESETDIFFRMS parameter is the median of the reset difference frame (master minus reference). The QC.RESETDIFFRMS is the robust RMS estimate of the bias difference frame.
As for all QC parameters that come
per chip, the upper left box of the
HC plot shows the average over 16 detector-specific
values, the lower left box shows the rms over 16
detectors, the upper right plot shows 16 individual
detector values, and the lower right plots shows the
detector specific scores.
Scoring&thresholds RESET frames
The reset level and the reset rms is trended and scored in
the upper left box of the plot. The rms of the difference
product as a highly sensitive parameter for the structural
noise in Uncorr read mode is monitored as well.
Relaxed scores are used.
When the instrument is warmed up and cooled down as part of a scheduled maintenance or an unexpected longer power cut on the site, the detectors show the following pattern: The reset level values and the reset rms values are higher than before the warm-up and decrease slowly in an asymptotic manner to the pre-intervention value. This might take weeks or longer. The strongest effect is seen in detectors #3, #13, and #14. From the long-term trend, the following warm-up events can be identified:
| 2012-12-10 || closed cycle cooler intervention, see PPRS 48376|
| 2013-08-06 |
| 2014-07-15 |
| 2015-03-25 |
| 2015-06-15 |
| 2015-11-25 |
| 2017-03-08 || closed cycle cooler intervention|
| 2017-05-03 || detector controller electronics power-cycled to reduce number of string horizontal stripes events in dark frames|
| 2018-06-20 || closed cycle cooler intervention|
| 2018-06-26 || The REFERENCE_RESET product has been updated. The new one is from 2018-06-26. The QC parameter shows now the deviations from the 2018-06-26 instance of the RESET product.|
Algorithm RESET frames
The median and the robust RMS (via MAD) of the PRO.CATG=MASTER_BIAS and the PRO.CATG=DIFFIMG_BIAS products are taken