.. _SimIntro

Introduction
============

The aim of the SIM :term:`Processing Function` (developped by OU-SIM) is to produce homogeneous simulated data amongst the :term:`ECSGS` in a coordinated way for integration, validation and verification of the complexe :term:`ECSGS` framework. Simulations produced by OU-SIM also serve for the End to End performance validation of the entire Euclid mission.

Within the :term:`ECSGS`, the SIM PF is primarily responsible for producing simulated level-1 data for the 3 Euclid channels: VIS, NISP-P and NISP-S. Further, the SIM PF produces simulated level-EXT data for DES, LSST, CFIS, WISHES, WHIGS, JEDIS and PANSTARRS surveys. 

.. figure:: dpcards/images/SIM_workflow.png

The SIM PF is divided into several :term:`Software Component`, which are combined inside the SIM :term:`Pipeline`. Interfaces between the different :term:`Processing Element` of the pipeline are file-based. In the figure below, only the data interfaces used by each component are shown. 

.. figure:: dpcards/images/SIM_interfaces.png

The detailed documentation of the SIM PF can be found in the `Software Design Document <https://euclid.roe.ac.uk/dmsf/files/16549/view>`_ on the Euclid Redmine.