@unpublished{TUW-232155, author = {Eysn, Lothar and Mandlburger, Gottfried}, title = {OPALS Basics, Interpolation, Features, Attributes, Filtering}, year = {2014}, note = {invited; talk: EUFAR2 Expert Working Group meeting: Airborne Laser Scanning Software, Vienna, Austria; 2014-11-20 -- 2014-11-21} }