NIR Calibrated Frame Catalog

$SetSchemaPath nir/euc-nir-CalibratedFrameCatalog.xsd

Data product name

$PrintDataProductName

Data product custodian

$PrintDataProductCustodian

Name of the Schema File

$PrintSchemaFilename

Last Edited for DPDD Version

1.1

Processing Elements Creating / Updating / Using the Product

Creators:

Consumers:

Processing Function using the products

  • PF-NIR

Proposed for inclusion in EAS/SAS

This product is proposed for inclusion in the SAS: yes

This is one of the main PF-NIR products and it is the catalog extracted from fully calibrated NIR Calibrated Frame image.

Data Product Elements

$PrintDataProductElements

Detailed Description of the Data Product

The DpdNirCalibratedFrameCatalog is the catalog extracted from the NIR Calibrated Frame.

../../_images/nirCalibratedCatalog.png

Fig. 18 : Graphical representaton of Data section structure for DpdNirCalibratedFrameCatalog

Main metadata stored into the Data structure are:

  • SpatialCoverage: the catalog sky coverage as polygon corners coordinates including the observation

  • SpectralCoverage: the filter list included into the catalog

  • CatalogDescription: a set of info to describe and identify catalog (i.e. origin, filepath)

  • ObservationId: the Observation ID

  • CalBlockId: the Calibration Block ID

  • CalBlockVariant: the Calibration Variant

  • DataStorage: the FITS file name

  • Instrument: Euclid Instrument

  • ObservationDateTime: Observation Date and Time

  • TargetPointing: Target Pointings Coordinates

  • DitherObservation: the Dither Observation

  • PhotometricCalibrated: Boolean value to identify if it is photometrically calibrated

  • QualityParams: list of Quality Parameters

As illustraded into the

Scientific FITS File

The catalog is stored in a FITS file which is linked in the Data.DataStorage metadata. The catalog is extracted from NIR Calibrated Frame and, therefore, its file structure reflects the origin FITS file.

It is then composed by a PRIMARY layer, with the main infomation on pointings, and other 16 layers, 1 layer for each detector, named DETxy.SCI` as in the NIR Calibrated Frame FITS file. These layers store a table with the extracted catalog for eahc detector.

The NIR_Catalog_Extraction task detects sources with a dedicated algorithm and, then, extracts source photometry (using SExtractor software) with 3 different methods: * MagAper: photometry with 6 pixels size aperture * MagAuto: as defined by SExtractor * MagPSF: a PSF fitting extraction performed by SExtractor

Primary layer

The FITS file has a PRIMARY header with main information on the pointing.

$PrintPrimaryHeader fit/euc-nir.xml nir.calCatalog

From the corresponding calibrated frame are inherited the pointing coordinates and all the keywords needed to univocal identify the observation (i.e. Observation Id, Dither and Exposure number).

Scientific layer

The NIR_Catalog_Extraction task extracts a catalog from each detector.

Catalogs have the next columns:

$PrintCatalog fit/euc-nir.xml nir.calCatalog

where are reported all the 3 photometies with the corresponding uncertaintains.

Quality Parameters

A very usefull section it could be the Data.QualityParams, here represented

../../_images/nirCalibratedCatalog_dqc.png

Fig. 19 : Graphical representaton of Data.QualityParams section structure for the DpdNirCalibratedFrameCatalog

It cointains some very useful information to describe the catalog content and verify its quality.

  • ObjectCount is the total number of sources

  • sections MagAper, MagAuto and MagPSF contain statistics on photometric measures obtained with the 3 different methods

  • sections Bright and Faint list statistics on photometric errors from the 3 extraction methods for the brighter and fainter part of the catalog.