Quality Control and
Data Processing

HC PLOTS
efficiency
counts
illumination stability
QC1 database (advanced users): browse | plot

ZIMPOL measures the polarimetry modulation-demodulation efficiency (short: MODEMEFF) by acquiring a set of images of a highly polarized internal flat field source. The P/I image represents a map of the modulation demodulation efficiency.

QC1_parameters

FITS key	QC1 database: table, name	definition	class*	HC_plot**	more docu
QC.MEDIANMASTER	sphere_zimpol_modem_eff..qc_med	master	HC		[docuSys coming]
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter **There might be more than one.

Trending

Scoring&thresholds ZIMPL Modemeff efficiency

The QC parameter is scored with thresholds based on statistical arguments.

History

No remarks.

Algorithm ZIMPL Modemeff efficiency

The median counts in the product frame.

QC1_parameters

FITS key	QC1 database: table, name	definition	class*	HC_plot**	more docu
[derived from a QC procedure]	sphere_zimpol_modem_eff..qc_raw_counts_iframe	mean counts in raw iframe	CAL		[docuSys coming]
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter **There might be more than one.

Trending

The four boxes show the counts in the raw frames of the modulation demodulation efficiency calibrations for

• both detectors (CAM1 and CAM2) and
• both readmodes (S= SlowPolarimetry and F=FastPolarimetry).

Scoring&thresholds ZIMPOL Modemeff counts

The QC parameter is scored.

History

No remarks.

Algorithm ZIMPOL Modemeff counts

The counts in the raw frames are composed of a bias level of ~1000 ADU plus lamp flux. For every raw frame, the counts are taken in
one even row (pixel area = [60 268 260 268]) and in
one odd row (pixel area = [60 269 260 269]).

The average over all raw frame planes of the cube is taken, resulting in a mean odd_row and a mean even_row counts for both detectors. The maximum between the even_row and odd_row values is taken, for both cameras separately. The maximum over all raw frames is taken. This QC parameter is used to check for saturation and under-illumination.

QC1_parameters

FITS key	QC1 database: table, name	definition	class*	HC_plot**	more docu
[derived by QC procedure]	sphere_zimpol_modem_eff..qc_plane_rms	rms over cube layers	CAL		[docuSys coming]
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter **There might be more than one.

Trending

The four boxes show illumination stability of the flat frames for

• both detectors (CAM1 and CAM2) and
• both readmodes (S= SlowPolarimetry and F=FastPolarimetry).

See plot tutorial for ZIMPOL flat frames for details.

Scoring&thresholds ZIMPOL Modemeff shutter

The thresholds have been choosen, that 50% flux reduction in a single flat gives a red score.

History

Modemeff calibations have been affeced by the shutter issue in the same way and in the same period as zimpol flats.

Algorithm ZIMPOL Modemeff shutter

The median counts in every plane of the raw frame cube is retrieved. The rms (not robust) of the sample is used as measure for the illumination stability.