Aerial Archaeology in Ireland - The Heritage Council

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Other material held by the GSI includes a set of non-stereoscopic Air Corps photos taken in the 1950s, although this is not a
complete national coverage. A set of 1995 vertical photography flown at a scale of 1:5,000 was recently purchased from the OSi
as the basis for 1:50,000 ortho-photography creating a digital mosaic map. There is a small amount of satellite imagery for Co.
Mayo. The GSI does not hold a significant set of oblique photography.
The GSI collection is available for viewing purposes only; copies of photographs are available from the OSi which is currently
scanning the images for GSI. The collection can be accessed during normal office hours, and there is a viewing charge of €13
(Student €4). An index for the photographs based on the National Grid is also available. A search service is provided, with simple
stereoscopes available to assist viewing. The majority of users are archaeologists. Although there are no records of actual figures,
this pattern of use is reported to be very marked, and is borne out by comments from archaeologists themselves. Several have
noted the relative ease of access to the GSI collection, compared with the OSi. Many archaeologists also ask to use the Air Corps
photos taken in the 1950s, although that set is not complete national coverage.
The GSI is responsible for the Irish National Seabed Survey data, including airborne lidar surveys (Section 3.4) off the west coast
of Ireland. Three areas have been surveyed: Mulroy Bay, Northern Donegal; Clew Bay, Co. Mayo; and Killalla Bay, Co. Mayo. While
the data has been used primarily for bathymetric purposes, field boundaries and disused jetties are clearly visible in the imagery.
For Phase 2 of the Survey, key bays and priority areas around Ireland have been targeted for integrated survey work. The areas
have been selected after intensive consultation among the various stakeholders, including the Underwater Archaeology Unit of
DoEHLG.
Air Corps, Baldonnell
The Air Corps holds a significant collection of historic aerial photography, virtually all dating from before the early 1970s when
responsibility for civil air photography was passed to the OSi. Reconnaissance for these purposes ceased in about 1978, though
reconnaissance and training for military purposes continue.
In terms of vertical air photography, there is
coverage of various areas dating from c. 1951
to the mid 1970s (e.g. Figure 8). None of this
represents complete coverage of Ireland, and
the emphasis tends to be on coastal areas.
Nevertheless, coverage is fairly extensive,
totalling around 200 rolls of up to 200 @ 9
x 9 inch frames, mostly taken at 10,500 feet
and some at 5,400 feet, mostly in stereoscopic
format with 60% overlap.
Figure 8: Air Corps vertical photograph of Newgrange,
Co. Meath, taken during low-angled sunlight on 20
December 1972 (Government Stationery Office)