On the emission region of Type II Radio Bursts in interplanetary shock fronts

In this contribution we analyze type II radio emissions observed by the WIND/WAVES radio instrument to determine the emission region in shocks fronts through out the use of the blast wave reconstruction technique. Our preliminary results suggest that the processes of emission of a type II radio burst occur not only in the upstream region of the shock (i.e. the region that precedes the collision), but also that there must be emission of the material that has been compressed, as well as the material that is in compression process within the structure of the shock itself.