Aerial Archaeology
MúzeumCafé 7.
The first aerial photographs for archeological purposes (for example of Stonehenge) were taken from balloons between 1900 and 1910. In Hungary the beginning of this research method, which commenced after World War I, is connected with the name of cartographer and army officer Sándor Neogrády. While taking cartographic pictures Neogrády turned his attention to some archeological phenomena still in good condition and photographed them. Regrettably most of his pictures was destroyed during World War II. The post-1945 decades did not favour this activity. Only from the 1970s did it become possible for the military or an individual researcher, if commissioned, to photograph archeological sites. Restrictions on aerial photography were considerably relaxed in the 1990s. Thus is became possible to initiate several archeological research projects involving aerial photography.
What is aerial archaeology good for?
Aerial photography for cartographic purposes is usually taken from a height of 2-3000 metres, with a vertical axis and fixed camera. Pictures produced in this way can also be utilised in archeology, since they provide an overview of a site. Yet, these shots are not usually suitable for detecting smaller sites and observing details. The use of satellite images has recently spread in Hungary. On reconnaissance flights explicitly for archeological purposes an archeologist can observe the area designated for research from a height of a few hundred metres and can take photographs and video recordings. She or he can choose the angle, the time of the flight, etc. From this height items can be detected which do not show up on the surface, since from above a site can be viewed in its totality. Several forms of aviation can be used for aerial archeology these days: two- and four-person Cessna single-engine aircraft, powered hang-gliders and paragliders. For longer flights the Cessna aircraft are the most suitable.
How can aerial photography be used in archeology?
From a height of a few hundred metres the traces of houses, holes, moulds and ditches several hundred or several thousand years old can be detected on surfaces completely changed and used for different purposes over time. For example, on a field in intensive agricultural use the colour of buried objects is a darker brown compared to the immediate surroundings. In the photos on pages 27 and 28 nearly the entire groundplan of a medieval market town (Bikács-Belsősziget) with streets and houses can be identified, due to the so-called plant signs. Changes in the soil are indicated by the vegetation. Plants can grow more vigorously in soil rich in humus than elsewhere. In spring, when vegetation is bright green (page 27) the darker green refers to earlier objects. During periods preceding harvest (page 28) partly the taller size of plants and partly their different colour indicate the traces of former human activity. A shadow effect can be found in winter, in the snow, (see photo on page 89). With the appropriate light, shadows enable orientation in bushy or wooded areas.
Today aerial reconnaissance and photography are vital for the archeological research of an area (for example, the complete identification of a county’s fortifications). With its help we can discover sites which can no longer be researched with traditional methods due to complete ruination.