Vis Large Flat Frame Product

Metadata

Data product name

DpdVisLargeFlatFrame

Data product custodian

VIS

Name of the Schema file

euc-vis-LargeFlatFrame.xsd

Processing Element(s) creating/using the data product

Used internally in OUVIS for science pipeline (ProcessField) during the Correction stage.

Processing function using the data product

VIS

Proposed for inclusion in EAS/SAS

Yes

Data product elements

Header

object of type sys:genericHeader

Data

object of type vis:visLargeFlatFrame

QualityFlags

object of type dqc:sqfPlaceHolder

Parameters

object of type ppr:genericKeyValueParameters

Detailed description of the data product

The Large Flat frame is the result of the Large Flat Calibration Pipeline. The product is a multiple extension fits with 144 extensions, based on the detectors with the EXTNAME noted as the QUADID. The product contains the correction factor in magnitude.

It is calculated using the self caibration field. Thus the Largeflat product is heavily reliant on its modelling based on the results of Astrometry and positions form the Crossmatch.

The processing also allows to calculate the QE of each quadrant. This coresponds to a constant value calculated during the surface fitting of the product. This constant is substracted from the image and saved in the keyword QE. The correction task adds this constant before the correction.

Name of file:

EUC_VIS_LARGEFLATCAL_[SCF_date]_[ExposureTime]__[YYYYMMDDThhmmss.s]Z.fits

where SCF_date is the date in format YYYYYMMDD of the first exposure of the selfcal field used and the end date is the production date.

Data Header

Primary Header:

SIMPLE

conforms to FITS standard

BITPIX

array data type

NAXIS

number of array dimensions

EXTEND

TELESCOP

INSTRUME

VERSION

DATE

OBSTYPE

SEQID

DATE-OBS

DATE-UTC

EXPTIME

VAL_STA

VAL_END

TIME_STA

TIME_END

SUBDETQE

True if QE offset has been subtracted from LSF

Extension Header:

XTENSION

Image extension

BITPIX

array data type

NAXIS

number of array dimensions

NAXIS1

NAXIS2

PCOUNT

number of parameters

GCOUNT

number of groups

DET_ID

QUADID

CCDID

WCSAXES

Number of coordinate axes

CRPIX1

Pixel coordinate of reference point

CRPIX2

Pixel coordinate of reference point

PC1_1

Coordinate transformation matrix element

PC2_2

Coordinate transformation matrix element

CDELT1

[mm] Coordinate increment at reference point

CDELT2

[mm] Coordinate increment at reference point

CUNIT1

Units of coordinate increment and value

CUNIT2

Units of coordinate increment and value

CTYPE1

Coordinate type code

CTYPE2

Coordinate type code

CRVAL1

[mm] Coordinate value at reference point

CRVAL2

[mm] Coordinate value at reference point

LATPOLE

[deg] Native latitude of celestial pole

MJDREF

[d] MJD of fiducial time

EXTNAME

extension name