.. _SHEIntermediateEuclidizedHSTImages:
  
Shear Intermediate Euclidized HST Images product
------------------------------------------------
  
Data product name
=================
.. DataProductNameStart
   
sheIntermediateEuclidizedHstImages
   
.. DataProductNameEnd
   
Data product custodian
======================
.. DataProductCustodianStart
   
SHE
   
.. DataProductCustodianEnd
   
Data model tag
==============
.. DataModelTagStart
   
8.0
   
.. DataModelTagEnd
   
Name of the Schema file
=======================
.. NameSchemaStart
   
ST_DM_Schema/dictionary/pro/she/euc-test-she.xsd
   
.. NameSchemaEnd
   
Schema documentation tag
========================
.. SchemaDocTagStart
   
:emphasis:`Documentation for data product element sheIntermediateEuclidizedHstImages:`
    
This product contains a set of Euclidized HST images required for calibration 
of the shear measurement methods, at an intermediate processing stage.

:emphasis:`Documentation for data product element Header:`
    
The generic header of the product.
   
.. SchemaDocTagEnd
   
Data product elements
=====================
.. DataProductElementsStart

* ValidityRange (ins:calibrationValidPeriod)
* EuclidizedHstObjectList (sheEuclidizedHstObject)
 * sheEuclidizedHstObject 1
  * DataStorage (dss:dataContainer)
  * PsfStorage (dss:dataContainer)
 * sheEuclidizedHstObject 2
  * DataStorage (dss:dataContainer)
  * PsfStorage (dss:dataContainer)
 * ...

   
.. DataProductElementsEnd
   
Processing Element(s) creating/using the data product
=====================================================
.. PECreatorStart

SHE_HSTCalibration
   
.. PECreatorEnd
   
Processing function using the data product
==========================================
.. PFUsingStart

SHE
   
.. PFUsingEnd
   
Detailed description of the data product
========================================
.. DetailedDescStart

In its final stage, this product contains a catalogue of postage stamps of
galaxies that fulfil a given set of search criteria and which are required
for the calibration of the shear measurement methods.
The catalogue will provide metadata for these galaxies.
It is joined by FITS files of the Euclidized HST postage stamp images
of the galaxes themselves and FITS images of the respective PSFs for the galaxy
images as derived from the HST exposures.

An intermediate stage provides the full-size FITS images of the reduced HST
exposures, each paired with a FITS image of the derived PSFs for these
exposures.

In order to produce the final stage products, the reduced HST exposures are
supposed to be injected into the OU-EXT AstroWISE database, subsequently
processed by existing OU-MER PFs for Euclidization, and finally Euclidized
postage stamps are re-extracted using OU-MER's object detection algorithms
on the set of selection criteria.

This way, a set of postage stamp images of galaxies of defined properties is
produced which look like they would appear if observed by Euclid, complying with
the actual OU-MER selection criteria.

Intermediate calibration algorithms can relate to the full-size HST frames
directly, however.

Intermediate Stage Products
+++++++++++++++++++++++++++

* Each reduced HST exposure is provided as a FITS MEF file, 
  of the following format:

  **HDU**

  *Header*

  The header will contain the originary HST FITS MEF metadata, plus some 
  added information on the reduction steps in the comments section.

  *Data*

  The data will contain the usual 6 MEF extensions of an HST FITS image file, 
  which are for each of the two HST CCDs the scientific image (SCI), 
  the error field (ERR) and the data quality field (DQ).

* The associated FITS file containing the derived PSF will be of the following
  format:

  **HDU**

  *Header*

  +----------------+----------------+-------------------------------------------------------------------------------+
  | Parameter name | Fits Data type | Brief description                                                             |
  +================+================+===============================================================================+
  | ROOTNAME       | A32            | Rootname of the HST observation set                                           |
  +----------------+----------------+-------------------------------------------------------------------------------+
  | VERS_PSF       | A8             | Version of the reduction code used in extracting the PSFs                     |
  +----------------+----------------+-------------------------------------------------------------------------------+
  | GRID_X         | I              | Grid size (PSF centers) in X dimension                                        |
  +----------------+----------------+-------------------------------------------------------------------------------+
  | GRID_Y         | I              | Grid size (PSF centers) in Y dimension                                        |
  +----------------+----------------+-------------------------------------------------------------------------------+
  | META_i         | TBD            | Set of further metadata for the PSF                                           |
  +----------------+----------------+-------------------------------------------------------------------------------+

  *Data*

  Data will provide a 2D floating point image extension
  for each of the two HST CCDs, 
  containing a grid of PSFs determined for the associated HST exposure.


.. DetailedDescEnd