Data Product for CovarTwoPCFWLShearPos2D.
.. include:: ../../wlsubstitutions.rst
.. _CovarTwoPCFWLShearShear2D:

Covariance of Tomographic Cosmic Shear Correlation Output Product
------------------------------------------------------------------

Data product name
=================
.. DataProductNameStart

CovarTwoPCFWLShearShear2D

.. DataProductNameEnd

Data product custodian
======================
.. DataProductCustodianStart

CM-2PCF-WL

.. DataProductCustodianEnd

Data model tag
==============
.. DataModelTagStart

|WLDMTAG|

.. DataModelTagEnd

Name of the Schema file
=======================
.. NameSchemaStart

euc-test-le3-wl-cm2pcf-ShearShear2D.xsd

.. NameSchemaEnd

Schema documentation tag
========================
.. SchemaDocTagStart

:emphasis:`Data product documentation:`

Data Product for CovarTwoPCFWLShearShear2D.

:emphasis:`Documentation for data product element dpdCovarTwoPCFWLShearShear2D:`

This product contains the covariance matrix for cosmic shear 2PCF.

:emphasis:`Documentation for data product element Header:`

The generic header of the product

:emphasis:`Documentation for data product element Data:`

The data of the product


.. SchemaDocTagEnd

Data product elements
=====================
.. DataProductElementsStart

Header of type: sys:genericHeader

Data of type: wlcm2pcf:covarTwoPCFWLShearShear2D

Parameters of type: ppr:genericKeyValueParameters


.. DataProductElementsEnd

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

CM-2PCF-WL

.. PECreatorEnd

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

SGS pipeline output product to be used by SWGs

.. PFUsingEnd

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

This output product is a fits binary table containing important input
parameters as keywords in primary HDU, and a binary table in the next HDU with the
covariance for cosmic shear as described in
 `le3.wl.cm2pcf.output.shearshear2d <https://gitlab.euclid-sgs.uk/ST-DM/ST_DataModel/tree/develop/instances/fit/euc-test-le3-wl.xml>`_.

Extra metadata associated to the FITS container are the following:

* **SpatialCoverage** a description of the spatial footprint [optional, cot:spatialFootprint],
* **CatalogSelection**: describing the selection in the input catalogues [optional, up to 4 elements]

  *  **CatalogFileName**: the name of the input catalogue [sys:dataFileName]
  *  **Selection**: selection associated to catalogue [string]
  *  **CatalogUse**: for which use case the catalog is employed (=["ShearShear"])
     [string among "PosPos", "PosShear", "ShearShear"]
  *  **CatalogInfo**:  whether position or shear information is used in this catalogue (=["Shear"])
     [string among "Pos", "Shear"]
  * **CatalogOrder**: order associated to catalogue for reporting (e.g. BIN_ID1)[int32]


Keywords
+++++++++++++

This fits table is expected to contain the following keywords in primary HDU,
characterizing the important parameters of the product:

#. **RS_EST**: choice of resampling estimator (Jackknife, Bootstrap) [StringKeyword]
#. **RS_STR**: choice of resampling strategy (Catalog, Spatial) [StringKeyword]
#. **THMIN**: minimal angular value chosen for spatial binning [DoubleKeyword]
#. **THMAX**: maximal angular value chosen for spatial binning [DoubleKeyword]
#. **OATH**: maximal open angle value used for the approximation [DoubleKeyword]
#. **THUNIT**: unit of spatial distance [StringKeyword]
#. **BINSCALE**: whether lin or log bins [StringKeyword]
#. **COORDSYS**: if spherical or cartesian computation of distances [StringKeyword]
#. **SHE_SOFT**: which SHE catalogue used [StringKeyword]
#. **SHE_SEL**: selection for shear catalogue [StringKeyword]
#. **SOFTNAME**: name of software used for 2PCF [StringKeyword]
#. **SOFTVERS**: version of software used for 2PCF [StringKeyword]

The cosmic shear 2PCF are defined as:

.. math::
    \xi_\pm &=\langle \epsilon_t \epsilon_t\rangle \pm \langle \epsilon_x \epsilon_x\rangle\\
    \xi_x &= \langle  \epsilon_t \epsilon_x \rangle

with :math:`\epsilon_t` tangential component and :math:`\epsilon_x` cross component of ellipticity.

Covariance table
+++++++++++++++++

The table (first HDU, EXTNAME="RS_COVAR_SHEARSHEAR2D") will contain the following columns:

#. **THETA_1**: first angular separation (center of spatial bin) [D, float64]
#. **THETA_2**: second angular separation (center of spatial bin) [D, float64]
#. **BIN_COMB1**: first index for combination of redshift bins [J, int32]
#. **BIN_COMB2**: second index for combination of redshift bins [J, int32]
#. **COV_PP_RS**: covariance between shear-shear :math:`\xi_+` components [D, float64]
#. **COV_MM_RS**: covariance between shear-shear :math:`\xi_-` components [D, float64]
#. **COV_PM_RS**: covariance between shear-shear :math:`\xi_+` and :math:`\xi_-` components [D, float64]

.. note::
    Under discussion is the possibility in the future of having as first HDU an
    estimate for Shot Noise :

    #. **THETA_1**: first angular separation (center of spatial bin) [D, float64]
    #. **THETA_2**: second angular separation (center of spatial bin) [D, float64]
    #. **BIN_COMB1**: first index for combination of redshift bins [J, int32]
    #. **BIN_COMB2**: second index for combination of redshift bins [J, int32]
    #. **COV_PP_SH**: covariance between shear-shear :math:`\xi_+` components [D, float64]
    #. **COV_MM_SH**: covariance between shear-shear :math:`\xi_-` components [D, float64]
    #. **COV_PM_SH**: covariance between shear-shear :math:`\xi_+` and :math:`\xi_-` components [D, float64]

.. DetailedDescEnd