Quality Control and
Data Processing

HC PLOTS
Flat mean
Flat_alignment avg
Flat_alignment per detector
browse | plot
TRACE_lxpos
TRACE_rxpos
TRACE_tilt
TRACE_width
TRACE_vigneting
QC1 database (advanced users): browse | plot

Lamp flats are taken daily, usually in following instrumental setups:

• WFM (WideFieldMode), NOAO (No AO), N_Blue (Nominal wavelenght range with Blue filter), SCII1.0 (readout mode)
• WFM (WideFieldMode), NOAO (No AO), E_Clear (Extended wavelenght range with Clear filter), SCI1.0 (readout mode)

Whenever science observations are executed in a different setup, the corresponding lamp flat frames are taken as well, e.g, in the AO (Adaptive Optics) mode.

Example of the raw lamp flat for CHANNEL 5 (EXTNAME=CHAN05). The full raw lamp flat frame consists of 24 of such extensions - one extension for each of the 24 channels of MUSE.

QC1_parameters

FITS key	QC1 database: table, name	definition	class*	HC_plot**	more docu
QC.FLAT.MASTER.MEAN	muse_lampflat..flat_mean	Mean value of the master flat before normalization	HC		[docuSys coming]
[calculated by QC procedure]	muse_lampflat..topslice_flux	avg flux of the 4 top row slices (10,22,34,46) normalized by avg flux in the channel	HC		[docuSys coming]
[calculated by QC procedure]	muse_lampflat..bottomslice_flux	avg flux of the 4 bottom row slices (3,15,27,39) normalized by avg flux in the channel	HC		[docuSys coming]
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter **There might be more than one.

Trending

The average value (averaged over all detectors) of the mean flux level of the lamp flat is trended. The flux level is determined before normalization. It is derived from the MASTER_FLAT calibrations. Also the rms of the average flux level is trended.

The IFUs' alignment is checked looking at the average flux in 4 top raw slices - slice 10, 22, 34, 46, and average flux in 4 bottom row slices: slice 3, 15, 27, 39. It is monitored as a function of time but also as a function of ambient temperature (INS.TEMP4.VAL, qc parameter "temp_ambient").

Only data taken in the instrumental mode (INS.MODE) WFM-NOAO-N and the read out mode (DET.READ.CURNAME) SCI1.0 are selected.

Scoring&thresholds LAMP FLAT mean

The thresholds are set to ensure optimal flux on the detectors and to warn about malfunction of the lamp. The thresholds are used for the HC setting - the lamp flat taken in the WFM-NOAO-N and WFM-NOAO-E modes. All other settings would need individual thresholds but are taken only sporadically (driven by science observations). Hence a threshold violation in a HC settings is taken as indication that the lamp flux level needs to be adjusted.

The alignment parameters are not scored.

History

Date	event
February 2014	lamp flat calibrations are taken regularly
March 18, 2015	flat lamps exchanged after showing flux decreasing trend over few months
2015-08-16	calibration lamps were changed
2016-03-14	both halogen lamps were changed
2017-02-23	the Blue halogen lamp was changed and no change was observed in the low flat field flux levels; Suspicion that the lower flux might be due to the liquid fiber degradation
2017-04-10	after recent adjustment of the both halogen lamps and of the integration time the thresholds were modified
2019-04-01	due to recent decrease of the continuum lamp flux the multiplier factor was changed from 3.38 to 3.58
2019-06-07	Neon Penray lamp was replaced (PPRS-076290)
2021-07-02	Continuum lamp multiplier adjusted (PPRS-080858)

Algorithm LAMP FLAT mean

This recipe combines several separate lamp flat images into one master lamp flatfield file and traces the location of the slices on the CCD. The master flat contains the combined pixel values of the raw flat exposures, with respect to the image combination method used, normalized to the mean flux. The lamp flat mean value for each detector (channel/IFU) is calculated on the master flat before normalization

The alignment parameters topslice_flux and bottomslice_flux are calculated as average flux in 4 top raw slices - slice 10, 22, 34, 46, normalized by the average flux in all slices in each channel and average flux in 4 bottom row slices: slice 3, 15, 27, 39, normalized by the average flux in all slices in each channel as well.

QC1_parameters

FITS key	QC1 database: table, name	definition	class*	HC_plot**	more docu
QC.TRACE.SLICE_L.XPOS	muse_tracetable..trace_slice_l_xpos	[pix] Location of midpoint of leftmost slice	HC		[docuSys coming]
QC.TRACE.SLICE_R.XPOS	muse_tracetable..trace_slice_r_xpos	[pix] Location of midpoint of rightmost slice	HC		[docuSys coming]
QC.TRACE.SLICE_L.TILT	muse_tracetable..trace_slice_l_tilt	[deg] Tilt of leftmost slice measured as angle from vertical direction	HC		[docuSys coming]
QC.TRACE.SLICE_R.TILT	muse_tracetable..trace_slice_r_tilt	[deg] Tilt of rightmost slice measured as angle from vertical direction	HC		[docuSys coming]
QC.TRACE.WIDTHS.MEAN	muse_tracetable..trace_wid_mean	[pix] Mean width of slices	HC		[docuSys coming]
[calculated by QC procedure]	muse_tracetable..topslice_width	difference in width of 2 top row slices: left (10) and right (46)	HC		[docuSys coming]
[calculated by QC procedure]	muse_tracetable..bottomslice_width	difference in width of 2 bottom row slices: left (3) and right (39)	HC		[docuSys coming]
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter **There might be more than one.

Trending

Trended are: tilt [deg], measured as angle from vertical direction, of the left-most and right-most slice, averaged across all the IFUs (CHANels) and mean value of the width of the slices [pix], also averaged across all the IFUs (CHANels).

Vignetting of the Calibration Unit mask is monitored by assessing difference in width of the slices: top left (slice10) and bottom left (slice 3), as well as top right (slice 46) and bottom right (slice 39).

Only data points extracted from LAMP_FLAT calibrations, PRO.CATG=TRACE_TABLE product of the muse_flat recipe, taken in the instrumental mode (INS.MODE) WFM-NOAO-N and the read out mode (DET.READ.CURNAME) SCI1.0 are selected.

Scoring&thresholds LAMP FLAT trace

No scoring

History

Date	event
February 2014	lamp flat calibrations are taken regularly

Algorithm LAMP FLAT trace

To trace the position of the slices on the CCD, their edges are located using a threshold method. The edge detection is repeated at given intervals thereby tracing the central position (the mean of both edges) and width of each slit vertically across the CCD. The trace table contains polynomials defining the location of the slices on the CCD. The vignetting parameters - topslice_width and bottomslice_width are defined as difference in the width of the top left (slice10) and bottom left (slice 3), as well as top right (slice 46) and bottom right (slice 39).