= PDAF - the Parallel Data Assimilation Framework =

{{{
#!html
<table align="right" width=300 cellpadding=10><tr><td>

<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>

</td></tr><tr><td>

<table align="right" style="border: 1px outset #ddc; background: #ccf;" cellpadding=5><tr><th align="center"><b>News</b></th></tr>
<tr><td><u>June 24, 2018</u><br>
New documentation: <a href="/trac/wiki/FirstSteps">First Steps with PDAF</a></td></tr>
<tr><td><u>April 5, 2018</u><br>
Update of <a href="/trac/wiki/PdafTutorial">implementation tutorials</a>. They now describe the new features of PDAF 1.13 and include hints on how to extend the tutorial implementations to more complex cases</td></tr>
<tr><td><u>March 12, 2018</u><br>
Release of Version 1.13.1 (<a href="/trac/wiki/ReleaseNotes">release notes</a>)<br>(added routine to retrieve assimilation flag and two bug corrections)</td></tr>
<tr><td><u>February 11, 2018</u><br>
Slides for PDAF tutorial at Ocean Sciences Meeting are now online (see <a href="/trac/wiki/PublicationsandPresentations">Publications and Presentations)</a></td></tr>
<tr><td><u>February 6, 2018</u><br>
Release of Version 1.13 (<a href="/trac/wiki/ReleaseNotes">release notes</a>)<br>(added model binding for MITgcm, new routines to simplify implementation of parallelized local analysis step)</td></tr>
</table>

</td></tr></table>
}}}


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]
{{{
#!html
<li><a class="wiki" href="/register/index.php">Software download</a></li>
}}}
 * Basic Documentation
   * [wiki:FirstSteps First Steps with PDAF]
   * [wiki:Lorenz_96_model Assimilation with the Lorenz-96 model and PDAF]
   * [wiki:SoftwarePackage Description of the software package]
   * [wiki:PdafTutorial Implementation tutorials]
   * [wiki:WhichFiltertouse Which filter should one use?]
   * [wiki:EnsembleGeneration Generating ensembles]
 * Full Documentation
   * [wiki:ImplementationGuide Implementation Guide for the online assimilation system]
   * [wiki:OfflineImplementationGuide Implementation Guide for the offline assimilation program]
   * [wiki:DataAssimilationDiagnostics Diagnostic routines]
   * [wiki:AvailableOptionsforInitPDAF Overview of filter-specific options]
   * [wiki:AddFilterAlgorithm Adding a filter algorithm to PDAF]
   * [wiki:RoutineOverviews Lists for direct access to documentation on particular routines]


 * [PublicationsandPresentations Publications and Presentations involving and about PDAF]