@unpublished{TUW-209053, author = {Weber, Robert}, title = {Globale Satellitennavigationssysteme - Status (Mitte 2012) und geplanter Systemaufbau}, year = {2012}, note = {invited; poster presentation: 11. {\"O}sterreichischer Geod{\"a}tentag, Velden, Austria; 2012-05-08 -- 2012-05-10} }