.. include:: ../../idsubstitutions.txt
.. _SELIDStatistics:

SEL-ID Purity and completeness statistics
============================================


Data Product Name
__________________
.. DataProductNameStart

DpdLE3IDSELIDStatistics

.. DataProductNameEnd

Data Product Custodian
_______________________
.. DataProductCustodianStart

IDSEL

.. DataProductCustodianEnd

Name of the Schema File
________________________
.. NameSchemaStart

.. raw:: html 

    <a href="https://gitlab.euclid-sgs.uk/ST-DM/ST_DataModel/-/blob/9.2.0/ST_DM_Schema/auxdir/ST_DM_Schema/dpd/le3/id/sel/out/euc-le3-id-sel-Statistics.xsd" target="_blank">euc-le3-id-sel-Statistics.xsd</a>

.. NameSchemaEnd

Last Edited for DPDD Version
____________________________
.. DpddVersionlTagStart

1.1

.. DpddVersionTagEnd

Processing Elements Creating / Updating / Using the Product
___________________________________________________________
.. PECreatorStart

**Creators:**

* SEL_PC

**Consumers:**

* SWG-GC

.. PECreatorEnd

Processing function using the data product
___________________________________________
.. PFUsingStart

LE3, SGS pipeline output product to be used by SWGs

.. PFUsingEnd

Proposed for inclusion in EAS/SAS
_________________________________

.. IncludeInSASStart

This product is proposed for inclusion in the SAS: yes

This product is needed to query the purity and completeness statistics of the galaxy samples used for galaxy clustering analyses.

.. IncludeInSASEnd

Data Product Elements
______________________
.. DataProductElementsStart

:Header: object of type sys:genericHeader
:Data: object of type selid:selIDStatistics
:QualityFlags: object of type selid:selStatisticsDqc
:Parameters: object of type ppr:genericKeyValueParameters

.. DataProductElementsEnd

Detailed Description of the Data Product
_________________________________________
.. DetailedDescStart

This is an output data product that stores the estimates of purity and completeness for the selected Wide samples.

Observationally, we define the H\alpha target sample with the following criteria applied to the Deep field catalog.

* Photometric selection: :math:`H<24`.
* Total line flux of the Halpha complex (H\alpha + [NII]) is greater than 2e-16 erg/s/cm2.
* Redshift in the range :math:`0.9 < z < 1.8`.

The *selected* sample is constructed based on the configuration of SEL. The threshold for a correct redshift estimate is
:math:`|z_{spe} - z_{true}| < 0.003`. Note that there is no :math:`1+z` scaling.

**Completeness** is the *sample completeness* defined as the fraction of the selected sample that are truly part
of the target sample and have a correct redshift measurement: :math:`C = \frac{N_{\rm selected, correct}{N_{\rm targets}}`.

**Purity** is the *redshift purity* defined as the fraction of the selected sample that have a correct resdhift measurement:
:math:`P = \frac{N_{\rm selected, correct-z}{N_{\rm selected}}`.

The purity and completeness are estimated using the Euclid Deep fields, and so are strictly relevant only at the locations of the Deep fields. **The purity and completeness statistics are not extrapolated over the Wide survey.** The VMSP random catalog may be used to estimate purity and completeness at an arbitrary position.

Metadata
++++++++
The metadata stored in the Data element of the XML contains useful information about the survey coverage. Here is a brief summary of the metadata:

**Data/**

+---------------------------+---------------------------+------------------------------------------------------------+
| Key                       | Type                      | Description                                                |
+===========================+===========================+============================================================+
| ConfigurationID           | str                       | Configuration identifier                                   |
+---------------------------+---------------------------+------------------------------------------------------------+
| Origin                    | str                       |                                                            |
+---------------------------+---------------------------+------------------------------------------------------------+
| Version                   | str                       |                                                            |
+---------------------------+---------------------------+------------------------------------------------------------+
| PatchTileList             | PatchTileList             |                                                            |
+---------------------------+---------------------------+------------------------------------------------------------+
| SelectionList             | Selection                 |                                                            |
+---------------------------+---------------------------+------------------------------------------------------------+

The `SelectionList` consists of a list of one or more `Selection` elements, each of which contains:

**Data/SelectionList/**

+---------------------------+---------------------------+------------------------------------------------------------+
| Key                       | Type                      | Description                                                |
+===========================+===========================+============================================================+
| Completeness              | float                     | Completeness estimate                                      |
+---------------------------+---------------------------+------------------------------------------------------------+
| ObjectCount               | float                     | Number of objects used for completeness-purity estimates   |
+---------------------------+---------------------------+------------------------------------------------------------+
| Purity                    | float                     | Purity estimate                                            |
+---------------------------+---------------------------+------------------------------------------------------------+
| SelectionID               | str                       | Selection identifier                                       |
+---------------------------+---------------------------+------------------------------------------------------------+
| SelectionName             | str                       | Selection name                                             |
+---------------------------+---------------------------+------------------------------------------------------------+
| CompletenessConfInterval  | Double2Type               | 95% confidence interval for completeness                   |
+---------------------------+---------------------------+------------------------------------------------------------+
| FileContainer             | DataContainer             | Pointer to file                                            |
+---------------------------+---------------------------+------------------------------------------------------------+
| PurityConfInterval        | Double2Type               | 95% confidence interval for purity                         |
+---------------------------+---------------------------+------------------------------------------------------------+

.. DetailedDescEnd