[to complete] NIR Large Scale Flat (LargeFlat)

Metadata

Data product name

DpdNirLargeFlatFrame

Data product custodian

NIR

Name of the Schema file

euc-nir-LargeFlat.xsd

Processing Element(s) creating/using the data product

The LargeFlat is created by the NIR_SelfCalib_Pipeline pipeline. This pipeline compare source fluxes extracted in dedicated Self Calibration Field observations to derive large scale pixel flux variations together with detector by detector offset tracked by the [to complete] NIR Relative Photometric Calibration factors among Detectors Data Product.

The task responsible for the LargeFlat creation is NIR_Compute (under NIR_SelfCalib project).

Processing function using the data product

This is an internal NIR data product, and it is used only by the NIR PF.

It is applied by the NIR_Apply task (under NIR_SelfCalib project) inside the NIR_ProcessField_Pipeline.

Data Product structure description

The main elements inside the “Data” section are:

  • Filter: The filter name (e.g. NIR_Y, NIR_J, NIR_H)

  • ValidityRange: Calibration file validity period estimated

  • DataStorage: Element that links to a FITS file containing the LargeFlat FITS file

  • QualityParams (optional): List of Detector Data Quality Parameters
    • Min: Minimum image pixel value

    • Max: Maximum image pixel value

    • Mean: Average image level (mean of all image pixel values)

    • Median: Median image level (median of all image pixel values)

    • StDev: Sample standard deviation of the image pixel values

    • MaskedPixelFraction: The fraction of masked pixels

FITS file description

The structure of the NIR LargeFlat is the same as the Science Image of the NIR Calibrated Frame with 16 x 3 layers, i.e. containing median large field correction, RMS, and Data Quality flags for each detector.

Primary header

The primary header contains keywords to identify FITS data type.