Archaeological surveying is a specialized type of land surveying conducted to report the finds made in an archeological site or to show the relationship of the archaeological site to the landscape. This survey is generally undertaken at the request of archeologists or government agencies and utilizes GIS, GPS, aerial photography, and other tools for surveying. In most cases, these surveys are done as remotely as possible to avoid disturbing the archaeological site.
While archeological land surveys are often conducted at the conclusion of an excavation, land surveying methods can actually be useful in identifying the sites prior to excavation. Previous uses of the land can leave physical marks on the modern landscape, such as raised ridges where the walls of buildings once stood. In many cases, these features cannot be noticed from the ground. Aerial surveying methods can be used to generate maps that show these markings from an aerial vantage point showing elevation changes, which can make such features clearer. This map can then be turned into a grid that guides the archaeological excavation of the site.
The aim of archaeological land surveying is to be as non-intrusive as possible. Unlike many other types surveys, it might not be possible for the surveyor to traverse the entire landscape on foot because of the sensitive nature of the archaeological finds. The type of survey undertaken on archaeological sites is often known as a ‘geophysical survey,’ and it may be conducted with LiDAR or other high-tech methods used to survey the area without setting foot on the actual terrain. In some cases, specialized equipment can map not only the above-ground artifacts (at the current stage of excavation) but also possible archaeological features buried underground. In the same way as above-ground surveys are constructed, the readings taken from the equipment become a dataset, which can then be rendered as a visible map of the area.
The result of an archaeological survey is a high-resolution image of the terrain. This display can take several forms depending on the intended purpose of the survey. It may be two-dimensional, recording the location of the site and surrounding terrain. It may be three-dimensional, providing additional information about the layout of the archaeological site, such as the height of any walls uncovered. In some cases, this data can be used to create a virtual ‘fly through,’ or a 3D image that can be manipulated to show the view from various points.
The results of an archaeological survey conducted after the area has been excavated become a record of the layout that can be compared to later surveys to determine the stability of the archaeological site and record any damage after excavation. This map can also be used as an all-encompassing view of the structures found by an archaeological excavation, providing the basis for research and other activities. In some cases, archaeological land surveys may also be required as evidence for the listing of such sites on registers of historic places.