What do we see?

When you take a photograph of a building it's relatively obvious what it is you are seeing whether you are on the ground or in the air. When it comes to the other types of sites covered by aerial survey it becomes rather more complex. An aerial view gives a new perspective on many types of sites and for some it is the only way to make any sense of what is there. 

The vast majority of specialist oblique aerial photographs held by the National Monuments Record are of sites known as cropmark sites. These are sites where there is little if any trace of whatever was there in the past visible on the surface. These sites can only be seen from the air as differential patterns of growth in crops as can be seen in the image on the left, or as colour changes in bare soil as can be seen in the image on the right. For further details of how cropmarks form and an explanation of what they tell us about what is hidden beneath the surface click here.

Whilst cropmarks are only visible from the air and show sites that have been completely levelled by later agricultural activity a large number of archaeological sites still remain as extant earthworks. These range from impressive prehistoric defensive enclosures such as Scratchbury Iron Age Hillfort to the left, to more ephemeral remains such as the faint traces of field system to the right. In both cases the low winter sunlight helps to emphasise the banks with highlights and deep shadows, a technique used to great effect when photographing earthwork sites.

The images used on this page are copyright English Heritage unless specified otherwise. For further details of any photographs or other images and for copies of these, or the plans and reports related to the project please contact the NMR English Heritage's public archive.

For further information on a project or any other aspect of the work of the Aerial Survey team please contact us at: AerialSurvey@english-heritage.org.uk.