Openness as Visualization Technique for Interpretative Mapping of Airborne Lidar Derived Digital Terrain Models

Openness is proposed as a visualization technique for the archaeological interpretation of digital terrain models derived from airborne laser scanning. In contrast to various shading techniques, openness is not subject to directional bias and relief features highlighted by openness do not contain any horizontal displacement. Additionally, it offers a clear distinction between relief features and the surrounding topography, while it highlights both the highest and lowest parts of features. This makes openness an ideal tool for mapping and outlining of archaeological features. A comparison with sky-view factor and local relief model visualizations helps to evaluate advantages and limits of the technique.