Quality Control and
Data Processing

HC PLOTS
relative deviation of total polarimetry in V, R and I
offset in polarimetric angle in V, R and I
Strehl ratio of acquired source
QC1 database (advanced users): browse | plot

The SPHERE calibration plan includes the observations of

• IRDIS CI/DBI: photometric standard stars and astrometric standard stars
• IFS: photometric standard stars and astrometric standard stars
• ZIMPOL-IMG: photometric standard stars and astrometric standard stars
• ZIMPOL-POL: unpolarized and polarized polarimetric standard stars

ZIMPOL unpolarized and polarized standard stars are acquired once a month in polarimatric mode in three broad band filters, once with closed loop and once with open loop, but both setups without coronograph. A further setup parameters are the neutral density filter.

ZIMPOL standard star observation raw frame.

ZIMPOL standard star observation.

QC1_parameters

FITS key	QC1 database: table, name	definition	class*	HC_plot**	more docu
QC.P.OFFSET	sphere_zimpol_stdpol_pol..qc_P_offset	offset from catalogue value	HC		[docuSys coming]
QC.THETA.OFFSET	sphere_zimpol_stdpol_pol..qc_THETA_offset	offset from catalogue value	HC		[docuSys coming]
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter **There might be more than one.

Trending

Polarimetric standard stars with high and zero polarimetry are acquired regularly in three broad band filters V, N_R and N_I in open loop and closed loop. The color filter correction is not applied for N snd I band. The closed loop observations are monitored.

Scoring&thresholds ZIMPOL polarimetric angle and total polarimetry

The values are not scored.

History

• The pipeline recipe was introduced in 2019.

Algorithm ZIMPOL polarimetric angle and total polarimetry

The sky is subtracted via a numerical aperture and the counts are integrated.