QC PLOTS
	CURRENT	HISTORY
Daily Health Checks:
flux range
QC1 hawki_dark database (advanced users): browse | plot
Click on CURRENT to see the last trending (Health Check).    Click on HISTORY to see the historical evolution of the trending.

This tutorial provides information for the the TW Flats Health Check trending.
The TW Flats trending is based on the measurement of QC1 parameters of Twilight Flat field calibration data obtained with a with OBs executed according to the calibration plan, meaning as required for the calibration of SCIENCE data during evening (usually) and morning (rarely) twilights with clear skies.
HAWK-I does not has an internal lamp. In the infrared twilight flats are taken in a manner to sample a large flux range by observing the twilight sky as the sun sets or rises. Twilight flats are therefore, one of the most time critical calibrations, since of the narrow time window. This is also the reason why more operational related quality parameters like the covered flux range are monitored for twilight flat calibrations. More 'classical' parameters which are on the current status of the instrunment itself are detector related characteristics like fixed pattern noise and optical path related ones like large scale gradients and the number of bad pixels .
The standard deviations of the pixel values of each detector in the MASTER FLAT image are monitored in J, H, Ks & Y filters.

QC1 parameters

• flux range within raw frame stack (QC1 database table hawki_twflat, column qc_flat_medstdev, product keyword QC.FLAT.MEDSTDEV)
  Description: The standard deviation of the raw frame fluxes as a rough measure of the covered flux range.