Quality Control and
Data Processing

Generally UVES-MOS calibration data are taken as day-time calibrations. On request by the user, also night-time calibrations (flat fields) can be obtained as part of the Observing Block which generates the SCIENCE data.For high-precision radial velocity studies, it is also possible to record an arc lamp spectrum simultaneously with the SCIENCE data.
All day-time calibration data are processed by QC Garching to obtain calibration solutions. These solutions come as

Calibration Raw Data

The following table contains an overview of the raw calibration files for the UVES echelle mode. The data types are identified with the DPR TYPE keyword of the fits headers.

frame	DPR TYPE	Purpose	typical number taken at night
BIAS	BIAS	detector status, bias level	5
DARK	DARK	dark current	3 per month for monitoring
FORMAT CHECK	LAMP,FMTCHK,SimCal	align spectral format to physical model	1
ORDER DEFINITION FLAT	LAMP,ORDERDEF,SimCal	define position of orders and interorder background	1
SLIT FLAT	LAMP,SFLAT	fix-pattern noise, fringing, slit function, blaze function	3 frames in 3 slit positions
FIBRE FLAT	LAMP,FLAT,ODD LAMP,FLAT,EVEN LAMP,FLAT,ALL	define fibre positions, correct for fibre cross talk	1 ODD-EVEN-ALL set

SLIT FLATs are similar to UVES Echelle flats but are taken in three different slit positions so that the whole space between two orders on the chip is covered. FIBRE FLATs come in three different varieties: with only ODD numbered fibres illuminated, with only EVEN numbered fibres illuminated, and with ALL fibres illuminated. All three varieties are measured in a sequence.
Examples of raw UVES-MOS frames and FITS headers are available from the FLAMES-UVES reference frames page.
For a complete overview of the data types and their dependencies, check the calibration cascade.

Calibration products

The following table contains an overview of the products calibration files for the UVES echelle mode.

raw frame(s)		recipe	description	product(s)
BIAS		uves_cal_mkmaster	create a master bias from set of input raw frames	MASTER_BIAS
DARK		uves_cal_mkmaster	create a master dark from set of input raw frames	MASTER_DARK (only occasionally produced)
FORMAT CHECK		flames_cal_predict	obtain first guess wavelength calibration solution	FIB_LIN_GUE, FIB_DRS TABLE
ORDER DEFINITION FLAT		flames_cal_orderpos	define order table and background table	FIB_ORDEF FIB_ORD_GUE table FIB_DRS table
SLIT FLAT		flames_cal_mkmaster	create a master flat from set of input flats	MASTER_SFLAT
FIBRE FLAT		flames_cal_sff_ofpos	create a master flat from set of input flats	FIB_ORDERDEF_TABLE FIB_FF_* SLIT_FF_*
WAVELENGTH CALIBRATION		flames_cal_wavecal	obtain wavelength calibration solution	FIB_LINE_TABLE, FIB_DRS_SETUP_TABLE

If there are several sets of daytime calibration data, only one is processed. If there are one or several sets of night-time calibration data, they are all processed.

Naming scheme

After production and certification, the calibration products are renamed after a scheme which includes type, creation data and relevant FLAMES/UVES setting parameters.
The naming scheme can be found here

Calib cascade

The processing of FLAMES/UVES calibration frames requires a cascading scheme where the mutual dependencies of products and raw frames have to be respected. Some products (master bias, first guess line table) can be produced from raw files only, but most products require the prior generation of other calibration products. The proper sequence of all these production steps is called the calibration cascade (see here ).
Within that cascade, all products are checked with respect to their quality and their relationship in time. This means e.g. that a master flat is not only generated using an arbitrary quality-checked order table, but that specific table is chosen which at the moment of processing is closest in time.
All products created by QC Garching respect the calibration cascade.