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Backend
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.. image:: images/PAVICS_architecture.png

The Backend of PAVICS-SDI is built entirely with Free and Open Source Software. All of the backend projects (source code and documentation) are open to be inspected, built upon, or contributed to. 

Birdhouse
---------

PAVICS is largely built upon the many components developed as part of the `Birdhouse Project <https://github.com/bird-house/birdhouse-docs/blob/master/slides/birdhouse-architecture/birdhouse-architecture.pdf>`_.

The goal of Birdhouse is to develop an easy-to-use Web Processing Service to support remote analyses of climate data using python. The library components of Birdhouse are called 'Birds' while each 'bird' is built to perform a specific set of functions within the Birdhouse ecosystem. PAVICS components that are borrowed from within the official Birdhouse structure are the following:

Birdhouse/Malleefowl
    Access to ESGF data nodes and THREDDS catalogs, workflow engine.
    `Malleefowl Official Documentation <https://malleefowl.readthedocs.io/en/latest/>`_

Birdhouse/Flyingpigeon
    Climate services including indices computation, spatial analogs, weather analogs, species distribution model, subsetting and averaging, climate fact sheets, etc.
    `Flyingpigeon Official Documentation <https://flyingpigeon.readthedocs.io/en/latest/>`_
    
Birdhouse/Hummingbird
    Climate Data Operators (CDO) and compliance-checker for netCDF files.
    `Hummingbird Official Documentation <https://birdhouse-hummingbird.readthedocs.io/en/latest/>`_

.. note::
	Are there any other birds worth mentioning here?

Other Projects
--------------

PAVICS-SDI relies upon several other projects specialized for spatial and climate data management and presentation.

THREDDS 
    A server system for providing scientific data and metadata access through various online protocols.
    `THREDDS Data Server Official Website <https://www.unidata.ucar.edu/software/thredds/current/tds/>`_ and `GitHub Repository <https://github.com/Unidata/thredds>`_

GeoServer
    A server system built for viewing, editing, and presenting geospatial data.
    `GeoServer Official Website <http://geoserver.org/about/>`_ and `Documentation <http://docs.geoserver.org/>`_

In-House Projects
-----------------

CRIM and Ouranos have also been actively involved in the planning and development of new and existing 'birds' to better perform very specific functions:

PAVICS-DataCatalog
    A database system for storing and serving information about available climate data.
    `PAVICS-DataCatalog GitHub Repository <https://github.com/Ouranosinc/PAVICS-DataCatalog>`_ 

Magpie
    Authentication and authorization services using RestAPI.
    `Magpie GitHub Repository <https://github.com/Ouranosinc/Magpie>`_

.. todo::
	Ask CRIM to review architecture backend