= PDAF - the Parallel Data Assimilation Framework =

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<table style="margin: 0 0 0 0; border: 1px outset #ddc; background: #ccf;" cellpadding=5><tr><td align="center">PDAF is developed, <br>hosted and maintained at the<br><a href="http://www.awi.de/en/research/scientific_computing/" target="_blank">Computing Center of the Alfred Wegener Institute</a>.</td></tr></table>

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<table align="right" style="border: 1px outset #ddc; background: #ccf;" cellpadding=5><tr><th align="center"><b>News</b></th></tr>
<tr><td><u>January 9, 2015</u><br>
New paper "On serial observation processing in localized ensemble Kalman filters" accepted for publication in the Monthly Weather Review (see <a href="/trac/wiki/publications/">PublicationsandPresentations</a>)</tr>
<tr><td><u>December 22, 2014</u><br>
Release of Version 1.11 (<a href="/trac/wiki/ReleaseNotes">release notes</a>)<br>(New: Improved screen output, OpenMP-parallelization of local filters, improved ensemble communication)</tr>
<tr><td><u>October 4, 2013</u><br>
Release of Version 1.10 (<a href="/trac/wiki/ReleaseNotes">release notes</a>)<br>(New: Simplified coupling method)</tr>
<tr><td><u>May 6, 2013</u><br>
Release of Version 1.9 (<a href="/trac/wiki/ReleaseNotes">release notes</a>)<br>(New: Smoother algorithms)</tr>
<tr><td><u>Jan 22, 2012</u><br>
Introducing a new filter algorithm: <a href="/trac/wiki/ErrorSubspaceTransformkf">The Error Subspace Transform Kalman Filter</a></tr>
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The Parallel Data Assimilation Framework - PDAF - is a software environment for ensemble data assimilation. PDAF simplifies the implementation of the data assimilation system with existing numerical models. With this, users can obtain a data assimilation system with less work and can focus on applying data assimilation.

PDAF provides fully implemented and optimized data assimilation algorithms, in particular ensemble-based Kalman filters like LETKF and LSEIK. It allows users to easily test different assimilation algorithms and observations. PDAF is optimized for the application with large-scale models that usually run on big parallel computers and is applicable for operational applications. However, it is also well suited for smaller models and even toy models.

PDAF provides a standardized interface that separates the numerical model from the assimilation routines. This allows to perform the further development of the assimilation methods and the model independently. New algorithmic developments can be readily made available through the interface such that they can be immediately applied with existing implementations. The test suite of PDAF provides small models for easy testing of algorithmic developments and for teaching data assimilation.

PDAF is an open-source project. Its functionality will be further extended by input from research projects. In addition, users are welcome to contribute to the further enhancement of PDAF, e.g. by contributing additional assimilation methods or interface routines for different numerical models. 



Content:[[BR]]
 * [FeaturesofPdaf Features and requirements of PDAF]
 * [GeneralImplementationConcept Implementation Concept of PDAF]
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<li><a class="wiki" href="/register/index.php">Software download</a></li>
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   * [wiki:SoftwarePackage Documentation on the downloadable software package]
 * Documentation
   * [wiki:PdafTutorial Implementation Tutorials]
   * [wiki:ImplementationGuide Implementation Guide for the online assimilation system]
   * [wiki:OfflineImplementationGuide Implementation Guide for the offline assimilation program]
   * [wiki:AvailableOptionsforInitPDAF Overview of filter-specific options]
   * [wiki:WhichFiltertouse Which filter should one use?]
   * [wiki:AddFilterAlgorithm Adding a filter algorithm to PDAF]

 * [PublicationsandPresentations Publications and Presentations involving and about PDAF]