To be able to combine different kinds of remote sensing and other archaeological data, archaeologists use software known as Geographic Information Systems (GIS). Using GIS we are able to integrate and analyse many different spatial data sets for the same region.
Within the GIS spatial data sets can be layered over each other, like a series of transparent maps. By combining information in this way archaeologists can identify patterns and relationships within the data. Archaeologists can overlay many datasets including historical mapping, remotes sensing data and environmental information to unravel the story of an archaeological landscape or in preparation for the excavation of a site.
While all the bits and pieces of the different remote sensing measurements might show interesting results on their own, a much more complete picture can be drawn when combining all this information. An aerial image may show the remains of a prehistoric ditch, whilst a lidar model can add the information on the shallow remains of a corresponding rampart. Finally a geomagnetic survey might explain if gaps in a fortification system have been caused by natural erosion, by destruction during a battle or if that gap was left intentionally when building the structure. GIS is also a powerful tool for archaeologist to manage their data sets, as remote sensing information can typically be Gigabytes (1,000Mb) to Terabtyes (1,000,000 Mb) in size.
GIS enable archaeologists to analyse and access such data with ease. The LiDAR data that was derived for the Celtic hillfort Glauberg in Germany (700km2) is about 12 Gigabytes in size, equivalent to the same information that is in 15,000 volumes of the last Harry Potter volume! Finally GIS enable archaeologists to present complex ideas and relationships using colourful descriptive graphics and map.