Quality Control and
Data Processing

HC PLOTS
photometric zeropoint 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 photometric standard stars are acquired once a month in imaging mode in three broad band filters, under photometric conditions, once with closed loop and once with open loop, but both setups without coronograph. A further setup parameters are the neutral density filter.

ZIMPOL photometric standard star observation raw frame.

ZIMPOL photometric standard star observation.

QC1_parameters

FITS key	QC1 database: table, name	definition	class*	HC_plot**	more docu
QC.ZPOINT	sphere_zimpol_stdphot_img..qc_zpoint	photometric zeropoint	HC		[docuSys coming]
QC.ZPOINTCORR	sphere_zimpol_stdphot_img..qc_zpoint_corrND	ZP corrected for ND filter	HC		[docuSys coming]
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter **There might be more than one.

Trending

Photometric standard standard stars are acquired regularly in three broad band filters V, N_R and N_I in open loop and closed loop. No airmass dependent extinction correction is applied. The neutral density filter correction is applied. The closed loop observations are monitored.

Scoring&thresholds ZIMPOL Photometric zeropoint

The values are not scored.

History

• The pipeline recipe was introduced in 2019. Observations have been processed from 2015-04 on.
• Observations acquired before 2017-01 are based on targets not supported by the standard star catalogue, hence no zeropoints are available in the period before 2017-01.

Algorithm ZIMPOL Photometric zeropoint

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