Quality Control and
Data Processing

Raw CALIB data types

The following calibration data are taken as part of the KMOS calibration plan. The data types are identified by the DPR TYPE keyword in the FITS headers.

frame	DPR.CATG	DPR.TYPE	DPR.TECH	purpose	N*
DARK	CALIB	DARK	IMAGE	detector bad pixels	>=3
FLAT	CALIB	FLAT,LAMP	SPECTRUM	localization of slitlets; fixed pattern noise, bad pixels	3 (per band and rotator angle)
	CALIB	FLAT,OFF	IMAGE	dark for flat	3 (per band)
ARC LAMP	CALIB	WAVE,LAMP	SPECTRUM	wavelength calibration	1 (per band and rotator angle)
	CALIB	WAVE,OFF	IMAGE	dark for arc lamps	1 (per band)
SKY FLAT	CALIB	FLAT,SKY	IFU	illumination correction	4
STD	CALIB	OBJECT,SKY,STD,FLUX	IFU	telluric correction	4

* N: typical number taken per night and setting

Flat-field and arc-lamp exposures are measured during daytime as part of the calibration plan. They are taken separately for each spectral band with a number of different rotator angles. For each band, a calibration sequence starts with one or several dark exposures (with DPR types FLAT,OFF or WAVE,OFF), followed by lamp exposures (with DPR types FLAT,LAMP or WAVE,LAMP) with varying rotator angles. The standard rotator sequence includes six angles: -60, 0, 60, 120, 180, 240 degrees. The sequence may be modified to closer match the rotator angles used during the night. An example sequence of arc-lamp exposures for the H band looks like:

ARCFILE	DPR.TYPE	INS.FILT1.NAME	INS.GRAT1.NAME	OCS.ROT.NAANGLE
KMOS.2013-09-17T22:43:00.335.fits	WAVE,OFF	Block	H
KMOS.2013-09-17T22:46:08.672.fits	WAVE,LAMP	H	H	-60.000
KMOS.2013-09-17T22:47:10.906.fits	WAVE,LAMP	H	H	0.000
KMOS.2013-09-17T22:48:13.225.fits	WAVE,LAMP	H	H	60.000
KMOS.2013-09-17T22:49:15.489.fits	WAVE,LAMP	H	H	120.000
KMOS.2013-09-17T22:50:17.904.fits	WAVE,LAMP	H	H	180.000
KMOS.2013-09-17T22:51:20.280.fits	WAVE,LAMP	H	H	240.000

Flat-field and arc-lamp calibrations may also be taken as part of an Observation Block that measures SCIENCE data during the night. Then, the rotator angle matches the actual state of the instrument at that time.

The processing of KMOS calibration frames requires a cascaded scheme where the mutual dependencies of products and raw frames are respected. The proper sequence of all these production steps is called the calibration cascade. It is described here.