# What is IFOS3D?**IFOS2D** (**I**nversion of **F**ull **O**bserved **S**eismograms) is a 3D elastic full waveform inversion code. The inversion problem is solved by a conjugate gradient method and the gradients are computed in the frequency domain with the adjoint method. The forward modeling is done by a time domain finite difference scheme. IFOS2D is the reverse (inverse) of our 3D finite difference forward solver [**SOFI3D**](https://git.scc.kit.edu/GPIAG-Software/SOFI3D).The [**manual**](https://git.scc.kit.edu/GPIAG-Software/IFOS3D/wikis/home) can be downloaded [here](https://git.scc.kit.edu/GPIAG-Software/IFOS3D/wikis/home).# Download and NewsletterYou can Download the current [**Beta-Version**](https://git.scc.kit.edu/GPIAG-Software/IFOS3D/tree/master).