[to complete] NIR Small Scale Flat (MasterFlat)

Metadata

Data product name

DpdNirMasterFlatFrame

Data product custodian

NIR

Name of the Schema file

euc-nir-MasterFlat.xsd

Processing Element(s) creating/using the data product

The MasterFlat is created by the NIR_MasterFlat_Pipeline which combines flat frames taken for the 5 LEDs in the NISP calibration unit.

The task responsible for the MasterFlat creation is NIR_construct_master_flat (under NIR_FlatFieldCorrection 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_flat_field_correction task (under NIR_FlatFieldCorrection project) inside the NIR_ProcessField_Pipeline and in most of the calibration pipelines.

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

  • CalibUnit: List of Calibration Units used for MasterFlat creation
    • LedId: ID of specific LED used. CULEDID keyword

    • FluxId: Led Flux ID. CULEDINT keyword

    • FluxVoltage (optional): LED Flux voltage (V)

  • DataStorage: Element that links to a FITS file containing the MasterFlat 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 MasterFlat is the same as the Science Image of the NIR Calibrated Frame with 16 x 3 layers, i.e. containing median flat field correction, RMS, and Data Quality flags for each detector.

Primary header

The primary header contains keywords to identify FITS data type.

In addition CULEDID and CULEDINT keywords are dedicated to track CalibUnit parameters.