At the core of the Historic Mapping Congress is the development of a spatial database of historic sites within a Geographic Information System (GIS). That database is being managed through Esri technology using ArcGIS software storing vector data (points, lines, or polygons) stored in either a geodatabase or shapefile format. Raster data (such as scanned images or surfaces) are stored as grids or in common image formats with an associated world file for georeferencing each image.
The geodatabase structure was developed specifically for our purposes according to the needs of historic researchers. The format is publicly available and can be downloaded here.
Data collection is commonly done using Global Positioning System (GPS) devices that calculate and store coordinates describing historic points (including mill sites, fords, ferry landings, chimney falls, battlegrounds, etc.) , lines (typically defining indian paths, roads, mill raceways, dams, lines of march, etc.), or polygons (commonly representing land parcels, burying grounds, battlefields, etc.)
A newer technology being leveraged in historic research is aerial remote-sensing with Light Detecting And Ranging (LiDAR)