Gerold ESSER / Mathias GANSPÖCK / Jan KANNGIESSER
Laserscanning is becoming a more and more refined and powerful working tool in cultural heritage documentation. In the field of archaeological and architectural documentation, and especially when combined with digital photogrammetry, it reveals its stunningly high potential which will finally question well established documentation procedures based on a purely tachaeometrical approach. Compared with conventional documentation techniques it strikes by its obvious capacity in documenting complete 3d surfaces hereby creating a consistent and textured 3d image of the historical artefact. All kinds of 3d modelling approaches have therefore been introduced into archaeological research projects often being time-consuming and difficult to handle. This paper is trying to show some less glamorous but on the other hand efficient and practical outcomes that can be generated out of 3d scanning data sets. Especially in the field of conservation of architectural objects where considerable alterations have to be implemented into the historical organism, 3d outcomes do not really meet the needs of planners. While on the one hand a full surface recording of the artefact is welcome to preservation authorities for pure documentation needs, planning architects are forced to deal with 2d materials. The example of the laser scanning campaign at castle Hochosterwitz shows, that both demands can be satisfied without the need of further tacheometrical measurements. Using innovative scanning devices the density and geometrical precision of point clouds assure that 2d planning materials up to a certain scale can be deduced without loss of exactness and reliability. The innovative new workflow also reveals to be more time and cost efficient than conventional tachaeometrical measurement procedures as time on site can be reduced while recording the full 3d geometry of the object. It is also more flexible because once a homogeneous data set of geometry and texture is recorded, all kinds of outcomes can be produced without the need of going back on site: groundplans, sections, oversights (Aufsichten?), prospects, and orthophotos are the outputs that are needed by planners and conservation architects.