# What is IFOS2D? **IFOS2D** (**I**nversion of **F**ull **O**bserved **S**eismograms) is a 2D elastic full waveform inversion code. The inversion problem is solved by a conjugate gradient method and the gradients are computed in the time domain with the adjoint method. The forward modeling is done by a time domain finite difference scheme. IFOS2D is the reverse (inverse) of our 2D finite difference forward solver [**SOFI2D**](https://git.scc.kit.edu/GPIAG-Software/SOFI2D). The [**manual**](https://git.scc.kit.edu/GPIAG-Software/IFOS2D/wikis/home) is included in the download archive or can be downloaded [here](https://git.scc.kit.edu/GPIAG-Software/IFOS2D/wikis/home). # Download and Newsletter You can Download the [**latest Release**](https://git.scc.kit.edu/GPIAG-Software/IFOS2D/tags/Release_2.0) or the current [**Beta-Version**](https://git.scc.kit.edu/GPIAG-Software/IFOS2D/tree/master) To receive news and updates please [register](http://www.gpi.kit.edu/Software-FWI.php) on the email list [IFOS@lists.kit.edu](http://www.gpi.kit.edu/Software-FWI.php). Please use this list also to ask questions on using the software or to report problems or bugs.