The Discovery Programme has had a long standing research interest at the Hill of Tara, Co Meath, one of Ireland’s best known archaeological sites, undertaking extensive topographic and geophysical survey on the ground since 1992. The terrain model generated from total station survey in the mid 1990’s was ground breaking at the time, a significant factor in furthering the understanding of the archaeological remains. Our desire to increase both the extent and resolution of the terrain model was realised when the Heritage Council provided financial support to enable a high resolution LiDAR to be commissioned.

The objective was to generate both a Digital Surface Model (DSM) – the landscape including trees, hedges, buildings etc (known as the first return) and a Digital Terrain Model (DTM) – the landscape with all upstanding features filtered out (known as the last return or bare earth). Both models would have a ground resolution appropriate to enable even the most subtle elements of the micro-topography to be seen, but this would not be restricted to simply the known monuments. Our intention was to cover the entire Tara landscape at this resolution, potentially revealing new discoveries, enhancing the understanding of the wider area and providing a definitive topographic base map, a GIS resource, to which further scientific data such as geophysical survey could be added.