Quality Control and
Data Processing

HC PLOTS
Sensitivity in LRS
Wavecal in LRS
QC1 database (advanced users): browse | plot

Spectro-photometric observations of telluric standard stars (of spectral types K or M) are provided by the observatory for low-resolution spectroscopy (LRS) with an airmass difference of less than 0.2 with respect to the science target.

LRS standard star frame. An example observation of a standard star in low-resolution spectroscopy with the post-upgrade detector. The integrated frame of all half-cycle frames at the first nodding position is shown.

QC1_parameters

FITS key	QC1 database: table, name	definition	class*	HC_plot**	more docu
QC.SENS.MEDIAN	visir_zp_spc..sens_median	median of spectroscopic sensitivities	HC		[docuSys coming]
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter **There might be more than one.

Trending

The median sensitivity over the whole spectrum is trended vs. time.

Scoring&thresholds Sensitivity

Scoring is not implemented.

History

Date	event
April 2015	start of operations after upgrade; trending of sensitivity in LRS has been introduced

Algorithm Sensitivity

Sensitivity is the estimated limiting flux expected in an 1 hour on-source integration of a point source detected with S/N of 10. The median over the whole spectrum is used here. Units: mJy at 10 sigma in 1hr.

QC1_parameters

FITS key	QC1 database: table, name	definition	class*	HC_plot**	more docu
QC.XFWHM	visir_zp_spc..xfwhm	FWHM at XCENTROI	HC		[docuSys coming]
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter **There might be more than one.

Trending

Image quality is trended since April 2015.

Scoring&thresholds Image quality

Scoring is not implemented.

History

Date	event
April 2015	start of operations after upgrade; trending of image quality in LRS has been introduced

Algorithm Image quality

FWHM of the spectral profile in cross-dispersion direction, measured in pixels and converted to arc seconds for trending.

QC1_parameters

FITS key	QC1 database: table, name	definition	class*	HC_plot**	more docu
QC.XCWLEN	visir_zp_spc..xcwlen	calibrated central wavelength	CAL		[docuSys coming]
QC.XCDISPX0	visir_zp_spc..xcdispx0	NULL	CAL		[docuSys coming]
QC.XCDISPX1	visir_zp_spc..xcdispx1	NULL	CAL		[docuSys coming]
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter **There might be more than one.

Trending

Parameters of the wavelength solution are trended since April 2015.

Scoring&thresholds Wavelength calibration

Scoring is not implemented.

History

Date	event
April 2015	start of operations after upgrade; trending of parameters from wavelength calibration has been introduced

Algorithm Wavelength calibration

Wavelength calibration is obtained from the sky lines present in the half-cycles frames of spectroscopic standard star and science observations. The dispersion solution is approximated with a first order polynomial:

lambda(i) = x0 + x1 * i