Primary header¶
The primary header contains keywords to identify FITS data type.
In addition CULEDID and CULEDINT keywords are dedicated to track CalibUnit parameters.
$PrintPrimaryHeader fit/euc-test-nir.xml nir.masterFlat
[to complete] NIR Small Scale Flat (MasterFlat)¶
$SetSchemaPath nir/euc-test-nir-MasterFlat.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 MasterFlat frame corrects the NIR science frames for variations in pixel response to a flat illumination. This Data Product is dedicated to track small scale variations, i.e. <100 pixels.
A MasterFlat frame for each filter is foreseen.
In addition, a set of metadata is used to describe the validity range and calibration units used to generate the MasterFlat.
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.
SCI Extension header¶
The scientific header contains some basic image definition keywords.
$PrintExtensionHeader fit/euc-test-nir.xml nir.masterFlat SCI.n