No particular code has been developed for the high resolution method during this thesis. We used the software cap (Kind (2002); Ohrnberger (2004); Ohrnberger et al. (2004); Ohrnberger (2001)). cap can access a GEOPSY database to obtain the input signals. It was available within the SESAME European project (Site EffectS assessment using AMbient Excitation, Project EVG1-CT-2000-00026).