Aerial Archaeology in Ireland - The Heritage Council

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Drawing on the work of O.G.S. Crawford and others working in England, Raftery (1944, 121-2) outlined the basic distinctions
between shadow, soil- and cropmarks. He drew attention to the technical importance of factors such as height, weather and
lighting in determining whether archaeological sites are visible from the air and the clarity of images that could be obtained.
Raftery also commented on the relative value of vertical and oblique photography. He drew attention to the potential for
identifying underwater sites, both in lakes and shallow coastal waters, which have ‘not been sufficiently exploited’ and the
potential for ‘ancient road systems, buried fortifications, and obscured burial places’.
An early example of the use of air photography in the Republic of Ireland that illustrates most of Raftery’s points had been
published in the report of a survey and excavation project carried out in 1940 at Caherguillamore, Co. Limerick (Ó’Ríordáin and
Hunt 1942). The air photography, taken by the Irish Air Force, was found to reveal a great deal more archaeology than was known
from the Ordnance Survey map. An interpretation plan published alongside the air photography was integrated with ground
observations to provide an overall commentary, adding a valuable interpretive context for the results of the excavation of two
medieval houses.
In the 1950s, the National Monuments Advisory Council commissioned the Air Corps to undertake some aerial archaeological
surveys — such as the 1950 vertical photography of the Brusselstown Ring hillfort in Co. Wicklow (Condit 1992). The Air Corps
remained an important contributor to the development of aerial archaeology in Ireland until the 1970s.
A more important development came when the challenge was taken up by J.K. St Joseph. The founder of the Cambridge
University Committee for Air Photography (CUCAP), St Joseph was one of the greatest exponents of purposive archaeological
and other landscape air photography in Ireland — as he was in England, Wales and Scotland. At the invitation of archaeologists
at the National Museum of Ireland, the Royal Irish Academy and the National Monuments Advisory Council, he undertook
two main campaigns of flying in Ireland — in 1951-5, and more particularly 1963-73 — when the CUCAP aircraft was based at
Dublin airport for about ten days each year. This remains the most extensive accessible collection of purposive archaeological
air photographic reconnaissance in Ireland, with over 10,000 images captured by 1968 (Norman and St Joseph 1969), and over
11,000 in all (for examples of the range of coverage, see Figures 10 to 13, 22, 38, 44, 45, 52).
Interest in the potential of aerial archaeology (including a brief résumé of techniques and sources of photography) was presented
to the 5th annual seminar of the Association of Young Irish Archaeologists (Patrick 1974).
In terms of vertical photography taken for general purposes, important early surveys were undertaken by the Army Corps, mainly
between 1950 and the early 1970s. The provision of this service for civil purposes was then transferred to the Ordnance Survey
Ireland (OSi). It remains the principal body carrying out such work, though on an increasingly commercial — and competitive
— basis. The GSI (from the 1970s onwards) and the Marine Institute (from 1998 to present) have also undertaken important
vertical surveys, and in the last ten years, increasing general use has been made of remote sensing techniques, though these
have yet to figure in the practice of aerial archaeology in Ireland.
Since St Joseph’s pioneering work, there have been other important private initiatives. These include those of the late Leo Swan
in the 1970s to 1990s, and Dr Daphne Pochin Mould (1978, 1981, 1991) from the 1960s to present, each running to thousands
of images (e.g. Figures 4, 15). From the 1980s onwards, many others have carried out analysis of air photography and/or aerial
reconnaissance in a variety of contexts, including the compilation of the SMR and County Inventories, regional or other surveys,
large-scale development projects, and a range of research projects (see below).
The 1990s and 2000s have seen a spate of new initiatives. These include the research reconnaissance of the Barrow Valley and
other parts of Ireland by Dr Gillian Barrett, and successive projects by the Discovery Programme, and various universities. Latterly,
the Heritage Council and the National Roads Authority (NRA) have sought to develop aerial archaeology as an integral element
of research and heritage management. But this work is not as widely recognised as it deserves to be, with Ireland still being
perceived externally as somewhere that has had little interest in the development and use of aerial archaeology (Musson and
Horne 2007, 4, 68).