Lidar provides a method for generating highly detailed height data over large areas in a small amount of time. Over the last few years an increasing amount of lidar data has been made available through the Geological Survey of Ireland’s (GSI) Open Topographical Data Viewer. This site includes data from GSI, Transport Infrastructure Ireland (TII), The Heritage Council and others.
This data is a valuable resource for identifying previously unrecorded archaeological sites. The detailed height data obtained by the lidar survey can be visualised in GIS as a hillshade, where an artificial light source is manipulated to accentuate shading. The data can also be processed to generate Sky View Factor visualistations.
It is clear from the visualisations below that there is much greater detail in the hillshade and sky view factor images, generated from TII lidar data, when compared to satellite photography.