Primary header¶
The primary header contains keywords to identify FITS data type.
$PrintPrimaryHeader fit/euc-test-nir.xml nir.largeFlat
[to complete] NIR Large Scale Flat (LargeFlat)¶
$SetSchemaPath nir/euc-test-nir-LargeFlat.xsd
Data Product Name¶
$PrintDataProductName
Data Product Custodian¶
$PrintDataProductCustodian
Name of the Schema File¶
$PrintSchemaFilename
Data Product Elements¶
$PrintDataProductElements
Detailed Description of the Data Product¶
The LargeFlat frame corrects the NIR science frames for variations in pixel response to a flat illumination. This Data Product is dedicated to track large scale variations, i.e. >100 pixels.
A LargeFlat frame for each filter is foreseen.
In addition, a set of metadata is used to describe the validity range and Quality Parameters.
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.
SCI Extension header¶
The scientific header contains some basic image definition keywords.
$PrintExtensionHeader fit/euc-test-nir.xml nir.largeFlat SCI.n