Quality Control and
Data Processing

HC PLOTS
Dark median
QC1 database (advanced users): browse | plot

Dark frames are taken about once a month in SCI1.0 read-out mode.

All QC parameters are computed for each IFU detector.

QC1_parameters

FITS key	QC1 database: table, name	definition	class*	HC_plot**	more docu
QC.DARK.MASTER.MEDIAN	muse_dark..master_median	Median value of the 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 current is trended for each IFU detector separately. The median value computed in ADU/hr/pix is monitored.

Scoring&thresholds DARK level

The dark_median is tightly scored, 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
February 2014	dark calibrations are taken regularly
2015-03-31	CHAN01 detector vessel exchanged, DET.CHIP.ID changed from psyche to egeria
2015-10-31	After intervention (detectors warmed up and vacuum recreated in the transfer lines) dark level in all quadrants back to normal values; PPRS-063339

Algorithm DARK level

Processing trims the raw data and records the overscan statistics, subtracts the bias (taking account of the overscan, if --overscan is not "none") from each raw input image, converts them from adu to count, scales them according to their exposure time, and combines them using input parameters. The combined image is normalized to 1 hour exposure time. The median level of master dark is calculated for each detector (i.e. channel/IFU).