HAWKI: Dark
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HC PLOTS |
Dark median |
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Dark ron |
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Reset anomaly |
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Ron vs. DIT |
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QC1 database (advanced users):
browse |
plot
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The HAWKI detectors' dark trending is based on measurement of the
QC1 parameters from the daily DARK calibration data. They are obtained
with dedicated Health Check OBs. Four sets of HAWK-I DARK frames with
four different DIT/NDIT/NEXP combinations are taken daily for
monitoring purposes. These data can of course also be used for
calibration of scientific data if necessary. The four DIT/NDIT/NEXP
combinations are: 1.6762/1/10, 2.0/1/10, 60.0/1/5 and 300.0/1/3. The
Median levels and ReadOut Noises trends are monitored for 2.0 and 300
second DITs and the Reset Anomolies and the ReadOut Noise vs. DIT
correllation relations are monitored from the minimum DIT (currently
1.6762sec) up to 300sec.
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Master DARK: This is an example of a
typical master dark frame. It contains 4 extensions
for each of the 4 chips of HAWK-I. Here shown together.
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DARK median
QC1_parameters
FITS key |
QC1 database: table, name |
definition |
class* |
HC_plot** |
more docu |
QC.DARK.MED | hawki_dark..qc_dark_med | median value across master dark
| HC | | [docuSys coming] |
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter
**There might be more than one. |
Trending
The dark level of the master dark in each of the 4
detectors is monitored.
Scoring&thresholds DARK median
The dark_median in each detector is scored individually, with dynamic
thresholds following the median average of the current
period. The only requirement on the dark current is stability on the calibration timescale.
History
Date |
event |
2014-02-01 | Bright darks on Feb 01 due to high detector temperature. Instrumentation worked on it and problem was fixed. |
Algorithm DARK median
A list of dark frames (at least 5 input frames,
usually 10) is combined into a mean dark product. The
mean value is estimated across the whole detector for
each chip separately.
DARK ron
QC1_parameters
FITS key |
QC1 database: table, name |
definition |
class* |
HC_plot** |
more docu |
QC.RON2 | hawki_dark..qc_ron23 | ReadOut Noise from (second-third) RAW frames
| HC | | [docuSys coming] |
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter
**There might be more than one. |
Trending
The read-out-noise estimated from the pair of the
2nd and 3rd exposure is monitored for each of the 4
detectors. Only the 2.0 and 300 second DIT calibration frames are used.
Scoring&thresholds DARK ron
The read-out-noise in each detector is scored individually, with dynamic
thresholds following the median average of the current
period. The only requirement on the dark current is stability on the calibration timescale.
History
Date |
event |
2016-11-19 | new, re-designed CASU pipeline was adopted in the QC system |
Algorithm DARK ron
A list of dark frames (at least 5 input frames,
usually 10) is combined into a mean dark
product. Read-out-noise is estimated from each pair of the
input frames.
DARK reset anomaly
The Reset Anomoly is a feature of certain detectors whereby after
the detector reset there is a period of time during which the rate of
dark current accumulation varies before settling into a (more or less)
constant rate of accumulation, e.g. as seen in ISAAC.
Based on long term trending it looks like HAWK-I does NOT suffer from a Reset Anomoly.
QC1_parameters
FITS key |
QC1 database: table, name |
definition |
class* |
HC_plot** |
more docu |
QC.DARK.MED | hawki_dark..qc_dark_med | median value across master dark
| HC | | [docuSys coming] |
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter
**There might be more than one. |
Trending
The dark median values are trended as a function of
data integration time (DIT).
Scoring&thresholds DARK reset anomaly
No scoring
History
Date |
event |
2016-11-19 | new, re-designed CASU pipeline was adopted in the QC system |
Algorithm DARK reset anomaly
No algorithm applied
DARK ron vs. DIT
QC1_parameters
FITS key |
QC1 database: table, name |
definition |
class* |
HC_plot** |
more docu |
QC.RON2 | hawki_dark..qc_ron23 | ReadOut Noise from (second-third) RAW frames
| HC | | [docuSys coming] |
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter
**There might be more than one. |
Trending
This correlation plot monitors for any correllation
between read-out-noise (RON) and data integration time (DIT).
Scoring&thresholds DARK ron vs. DIT
No scoring
History
Date |
event |
2016-11-19 | new, re-designed CASU pipeline was adopted in the QC system |
Algorithm DARK ron vs. DIT
No algorithm applied
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