Database and Geographic Information System
All of SCSP's diverse landscape data were stored, manipulated and analysed on a relational database (Filemaker Pro 4.0) which exported directly into our GIS (MapInfo Professional 5.5). The database consists of 14 core tables holding some 28,900 records. Most of these hold artefactual and environmental information on the survey units and POSIs, and the analyses of the artifacts described in the previous section. This database allowed us to store, audit and process our data efficiently, to carry out some basic statistical analysis, and most importantly to export the data to the GIS for spatial analysis.
The base layer of our GIS consisted of a series of aerial photographs (1993 photographs for our Special Interest Areas and 1963 photographs for the rest). The 1963 photographs were georegistered to the UTM grid using the 1:50,000 topographic map, while the 1993 ones were orthorectified using differential GPS control points and ERDAS Imagine software. Once georegistered, prints of these aerials were used as our basic mapping tool in the field, and allowed us to digitise all our survey units, POSIs and other landscape features each afternoon.
When the artefactual and statistical data were imported into the GIS from the database, we were able to carry out a series of spatial analyses on artifact distribution, and to compare these distributions with landscape features and processes such as soil erosion, arable land and ore sources. In each case the artifact densities were adjusted to allow for the square area of the unit (calculated by the GIS) and the ground visibility and background confusion (recorded by the survey team). In the case of the pottery, our representative collection method allowed us to project from the number of collected sherds of a specific period in the survey unit to the total number of sherds of that period. These GIS-generated density maps are our primary analytical tool, and examples can be seen in the SIA pages.
The SCSP Digital Archive consists of all our database files, GIS files and density maps, a sample of landscape and artifact photographs, a series of field reports, and an overview. This archive has been deposited with the Archaeology Data Service, who will maintain them and present them on their website for downloading. The SCSP Paper Archive consists of all of the original forms, drawings and photographs, and is held at the Department of Archaeology, University of Glasgow.