Aerial Archaeology in Ireland - The Heritage Council

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• A practical handbook in archaeological aerial photography and remote sensing in Ireland and other
means of promoting best practice (see also Recommendation 10) need to be developed.
Key organisations — Heritage Council; Royal Irish Academy in collaboration with Institute of Archaeologists
of Ireland; DoEHLG; AARG
The Value of Reconnaissance and Potential for Updating the Record
The discovery of additional earthwork remains is affected by reconnaissance altitude, lighting and vegetation. Cropmark sites
are affected by seasonal weather and cropping patterns, and their discovery is cumulative over several ‘good’ years, not single
exceptional years. The ‘yield’ of new discovery is further affected by levels of reconnaissance. Documented cases in Ireland
indicate 50% to 400% increases in site identification from thorough desk studies and/or reconnaissance. There is some material
in private — and some public — collections and archives which is not covered in the original compilation of the national
SMR which, of necessity, focused on the main sources. There is significant scope for enhancing the record, both from archival
material and new reconnaissance, but efforts need to be clearly targeted on key areas and issues, and undertaken in ways that
systematically help to clarify the nature of the evidence. For example, it would be useful if all new initiatives were tasked with
identifying and mapping inherent trends and distortions in the pattern of aerial discovery (especially in respect of cumulative
observations and possible reasons for absence of evidence), both as an indication of reliability of evidence and potential areas
needing further aerial reconnaissance.
Recommendation 4: Further work is needed to assess the full potential for enhancing the SMR from
as yet unarchived aerial photographic material and recent surveys, and to develop a strategy for new
reconnaissance.
• A strategic policy for new aerial reconnaissance for archaeology in relation to land-use change should
be developed and agreed. This should include the potential for developing specific projects focussed on
key areas and issues.
Key organisations — Heritage Council; DoEHLG (Planning); NMS; Representatives of local authorities and other
land-use regulators
Interpretation and Mapping
Archaeologists would like to see more effort put into detailed mapping and interpretation of evidence from aerial archaeology.
Some innovative work is being done in Ireland, for example by the Discovery Programme and others, including Redfern (1998,
2002), and Shell and Roughley (2004); a range of other methods is being used by practitioners. While it may not yet be realistic
to embark on a major national mapping programme such as that which exists in England, it is important that progress be made
in this area. The Discovery Programme and other research bodies define their own research-led needs. In relation to more general
purposes, minimum standards for mapping and presentation of the results of aerial survey need to be developed to ensure that
results are commensurate with the main uses to which the data will be put. For example, in relation to regulating development
and land-use change, interpretive mapping might be less detailed than would be needed for a major research project.
Recommendation 5: Further development of mapping (rectification, transcription, image enhancement
and integration with terrain models) should be encouraged, and a strategy developed for strategic mapping
of the results of aerial reconnaissance in areas under pressure of development, especially where subject to
Strategic Environmental Assessment (SEA).