Quality Control and
Data Processing

HC PLOTS
Visibility
Closure phase
Polarimetric phase difference
Transmission
QC1 database (advanced users): browse | plot

Calibrator stars are typically measured immediately before and/or after the science observation in order to determine both visibilities and phases of the fringes. An exposure sequence on the calibrator target is normally accompanied by an exposure on sky.

Calibrator. Medium resolution, combined polarimetry.

QC1_parameters

Instrumental visibilities are calculated from a single calibrator observation.

FITS key	QC1 database: table, name	definition	class*	HC_plot**	more docu
QC.TF.VISAMP_FT12_P1.MED	gravity_vis..tf_visamp_ft12_p1	transfer function visibility amplitude	HC		[docuSys coming]
QC.TF.VISAMP_SC12_P1.MED	gravity_vis..tf_visamp_sc12_p1	transfer function visibility amplitude	HC		[docuSys coming]
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter **There might be more than one.

Same for baselines 13, 14, 23, 24, and 34. Only P1 beam in case of split polarimetry.

Trending

The QC1 parameters are trended for FT and SC and for the six combinations of resolution and polarimetry mode. Results from ATs and UTs are monitored separately.

Scoring&thresholds Visibility

Scoring is not implemented.

History

No particular events.

Algorithm Visibility

Pipeline recipe. Visibility amplitudes of the transfer function, averaged over wavelength.

QC1_parameters

FITS key	QC1 database: table, name	definition	class*	HC_plot**	more docu
QC.T3PHI_FT123_P1.AVG	gravity_vis..t3_phi_ft123_p1	T3 phi in degrees	HC		[docuSys coming]
QC.T3PHI_SC123_P1.AVG	gravity_vis..t3_phi_sc123_p1	T3 phi in degrees	HC		[docuSys coming]
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter **There might be more than one.

Same for triangles 124, 134, and 234. Only P1 beam in case of split polarimetry.

Trending

Results from ATs and UTs are monitored separately.

Scoring&thresholds Closure phase

Scoring is not implemented.

History

No particular events.

Algorithm Closure phase

Pipeline recipe: sum of the phases of three baselines inside a triangle. For the four telescope triangles 123, 124, 134, and 234, and for FT and SC, averaged over wavelength.

QC1_parameters

FITS key	QC1 database: table, name	definition	class*	HC_plot**	more docu
QC.PHASE_POLDIFF_FT12	gravity_vis..phasediff_ft12	phase difference of the polarimetric beams	HC		[docuSys coming]
QC.PHASE_POLDIFF_SC12	gravity_vis..phasediff_sc12	phase difference of the polarimetric beams	HC		[docuSys coming]
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter **There might be more than one.

Same for baselines 13, 14, 23, 24, and 34. Only in case of split polarimetry.

Trending

The QC1 parameters are trended for FT and SC and for split polarimetry. Results from ATs and UTs are monitored separately.

Scoring&thresholds Phase difference

Scoring is not implemented.

History

No particular events.

Algorithm Phase difference

Pipeline recipe. Average phase difference of the two polarimetric beams.

QC1_parameters

FITS key	QC1 database: table, name	definition	class*	HC_plot**	more docu
QC.TF.TRANS_FT1	gravity_vis..trans_ft1	total transmission from target to detector (%) for FT	HC		[docuSys coming]
QC.TF.TRANS_SC1	gravity_vis..trans_sc1	total transmission from target to detector (%) for SC	HC		[docuSys coming]
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter **There might be more than one.

Same for telescopes 2, 3, and 4.

Trending

The QC1 parameters are trended for FT and SC and for the six combinations of resolution and polarimetry mode. Results from ATs and UTs are monitored separately.

Scoring&thresholds Transmission

Scoring is not implemented.

History

No particular events.

Algorithm Transmission

Pipeline recipe. Total transmission from target to detector (in per cent) for FT and SC, respectively, and from the four inputs. Note that input 1 corresponds to AT4 or UT4, input 2 to AT3 or UT3, etc.