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 hawki_dark :: HAWK-I_QC_DARK
 QC PLOTS CURRENT HISTORY Daily Health Checks: DARKMED DARKRON DARKRON12 DARKRON23 RESETANOM RONvsDIT QC1 hawki_dark database (advanced users): browse | plot Click on CURRENT to see the last trending (Health Check).    Click on HISTORY to see the historical evolution of the trending.

 top Introduction

This tutorial provides information for the the Detector: dark Health Check trending.
The Detector: dark trending is based on the measurement of QC1 parameters of DARK calibration data obtained with dedicated Health Check OBs executed daily.
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.

 top HAWK-I_QC_DARK

QC1 parameters

• DARKMED: mean of median values of input RAW frames (QC1 database table hawki_dark, column qc_dark_med, product keyword QC.RAW.MEDIAN.MEAN)
Description: Mean of the medians from each input frame. The QC parameter QC.RAW.MEDIAN.MEAN [ADU] is the mean of the medians calculated for each extension of each frame of the input frame set for the zone specified by the esorex commandline option --zone.
Note: This is currently being used as an estimate of the median value across master dark in [ADU]. In early versions of the pipeline this was provided by the QC parameter QC.DARK.MEDIAN, but with version 1.4.0 of the pipeline, the definition of the master dark was changed so that it was provided in [ADU/sec] units rather than [ADU] and with it the QC.DARK.MEDIAN QC parameter was changed.
• DARKRON: Mean of the ReadOut Noise of each pair of RAW frames (QC1 database table hawki_dark, column qc_ron_mean, product keyword QC.RON.MEAN)
Description: Mean of the RON (QC RONi) from each input frame. The RON of each extension of the ith frame of the frame set [RONi] is calculated as follows:
• Generate N WxW windows on the input pixel surface where N is specified by the esorex recipe command line option --nsamples and W is 2xH+1 where H is specified by the esorex recipe command line option --hzize. These windows are optimally scattered using a Poisson distribution to make sure they sample the whole area with as little overlap as possible.
• Compute the standard deviation of pixel values in each window.
• The readout noise of the nth frame is the median of all these measured standard deviations multiplied by $\sqrt{\frac{NDIT}{2}}$.
• The QC parameter QC.RON.MED [ADU/pix] is then the mean, median and standard deviation respectively of the n median values of n frames of the frame set.
• DARKRON12: ReadOut Noise from (first - second) RAW frames (QC1 database table hawki_dark, column qc_ron12, product keyword QC.RON1)
Description: Measured read-out noise of the whole array of each input frame. The QC parameter QC.RON1 [ADU/pix] standard deviation of the difference between the first image and the second image of the frame set for each of the four extensions.
• DARKRON23: ReadOut Noise from (second - third) RAW frames (QC1 database table hawki_dark, column qc_ron23, product keyword QC.RON2)
Description: Measured read-out noise of the whole array of each input frame. The QC parameter QC.RON2 [ADU/pix] standard deviation of the difference between the second image and the third image of the frame set for each of the four extensions.
• RESETANOM: Reset Anomaly (QC1 database table hawki_dark, columns qc_dark_med & dit, product keywords QC.RAW.MEDIAN.MEAN & DET.DIT)
Description: Dark current versus exposure time. This correlation plot monitors for any correllation between DARK current and exposure time, the so-called "Reset Anomaly" as seen in other IR instruments, such as ISAAC.
• RONvsDIT: Readout Noise versus DIT (QC1 database table hawki_dark, columns qc_ron_med & dit, product keywords QC.RON.MED & DET.DIT)
Description: Readout Noise (RON) versus exposure time. This correlation plot monitors for any correllation between Readout Noise (RON) and exposure time.

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