Box 1 shows the median BIAS level measured across the whole CCD, given in ADU, for the 'Normal' read mode. It is calculated by the QC procedure (for historical reasons). TITLE QC1 parameters TABLE_NAME qc1 TABLE_TYPE QC1_TABLE TABLE_ROW1 [BIAS_level calculated by QC procedure] SEP giraffe_bias..median_master TITLE Trending
The median bias level is plotted in box 1 of the trending plot.
TITLE Scoring&thresholds Normal read mode:
- The median_master is tightly scored, with dynamic thresholds following the median average of the current period. The only requirement on the bias level is stability on the calibration timescale.
- The sigma_raw (read noise) is scored statistically, it is very stable. The
same is true for sigma_master which however could produce artificial outliers
if less than 5 (or more than 5) input frames get combined.
- The structure
parameters are loosely scored, there is no requirement other than stability on
the calibration timescale.
- For the number of "bad" pixels there is no requirements other than the
detection of sudden outliers.
Fast read mode:
The same applies to the Fast read mode bias plots, with the exception of
median_master which is scored in a less restrictive way then the normal data
because this mode is very rarely used and sufficiently monitored with the
'normal' mode.
TITLE History
The mean bias has slowly decreased over the years.
TITLE Algorithm
The median of the whole master_bias is calculated, values below 100 and above 300 ADU are clipped.