NIR Calibrated Frame

Data product name

CalibratedFrame

Data product custodian

NIR

Data model tag

R-1.6.7

Name of the Schema file

euc-test-nir-CalibratedFrame.xsd

Schema documentation tag

Documentation for data product element DpdNirCalibratedFrame:

Calibrated science frame for dithered observations.

Data product elements

Header of type: sys:genericHeader

Data of type: nir:calibratedScienceFrame

Parameters of type: ppr:genericKeyValueParameters

Processing Element(s) creating/using the data product

It is created by the NIR_AbsolutePhotometry PE.

It is used by the NIR_Resampling PE.

Processing function using the data product

Used by MER PF.

Detailed description of the data product

This is an output data product of the NIR PF dedicated to the calibrated frames to be used by MER PF for catalogue extraction. These are pre-processed images where detector signatures have been accounted for, and that include astrometric and photometric calibrations.

It consists of 3 FITS files respectively for the Science image, the background model, and the PSF model:

  • Science Image: MEF with primary and 16 x 3 extensions, i.e. 3 layers per detector representing calibrated science image, RMS, and Data Quality flags.

  • Background model: MEF with primary and 16 x 3 extensions, i.e. 3 layers per detector representing background image, RMS, and Data Quality flags.

  • PSF: currently a single extension FITS file containing the PSF image associated to the science image. It will be extended to include wavelength and focal plane dependent PSF.

The MEF 3-layer format, shown in Fig. 14 is managed by the Euclid Image library EL_ImageLib

../../_images/calframe.png

Fig. 14 : 3-layer structure of NIR calibrated frames

The EXTNAME keywords for detector XY follow the convention DETXY.SCI, DETXY.RMS, and DETXY.DQ, for science, RMS, and Data Quality layers respectively.

Note that background is not removed from science images, and that pixel values are still in native units (electrons). Relative and absolute calibration factors for each detector for conversion to microJy are included in the metadata, as well as zero-points for conversion to AB magnitudes.

The DQ flags follow a common dictionary described here.