Traditional and well-established applications of airborne remote sensing to archaeology involve standard aerial photographic recording, either oblique or vertical, of archaeological phenomena visible as shadow, soil or cropmarks, all of which require particular conditions before they become visible. Cropmarks have made the most important contribution to archaeological site discovery and are the most complex of the phenomena, whose occurrence relies upon the differential availability of moisture to a crop growing over buried archaeological remains, reflecting different soil depths and precipitation, to create differential growth patterns in times of moisture stress. Consistently successful aerial photographic reconnaissance for cropmarks relies on dry weather and well-drained soils in arable agriculture. There is, thus, in Scotland a bias in the discovery of archaeological sites in favour of drier eastern districts, supporting arable agriculture, compared to the west with its wetter climate focussed on pastureland. Because cropmarks are linked to moisture stress in growing plants they are potentially detectable in bands outside the visible part of the electro-magnetic spectrum. Although historically cropmark detection has used film, whose sensitivity closely approximates the human eye, hyperspectral scanning allows consideration of a wider range of different wavelengths, beyond the visible spectrum, many of which are more sensitive to changes in vegetation status. The main objectives of this research are to test to what extent hyperspectral and multispectral imagery can reveal otherwise invisible archaeological sites surviving as cropmarks; to assess the relative usefulness of the different sensors employed; and to investigate the potential of hyperspectral and multispectral imagery to augment cropmark detection rates in areas less conducive to their production. It uses a range of imagery (CASI 2, ATM and digital vertical photographic data) acquired by NERC ARSF from two case study sites in Lowland Scotland, one in the east and one in the west, selected to facilitate comparison between areas of good and poor cropmark production. Following processing, comparison and detailed analysis of this data, this thesis has demonstrated the high efficacy of this imagery in the identification of archaeological cropmarks; has established the most appropriate range of bandwidths and processing methods applicable to that imagery; has demonstrated its potential for the discovery of previously unrecognised archaeological sites in areas of lowland pasture; and has reinforced the value of systematic block coverage as compared to traditional ‘observer-directed’ archaeological aerial reconnaissance.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:501480 |
| Date | January 2009 |
| Creators | Aqdus, Syed Ali |
| Publisher | University of Glasgow |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://theses.gla.ac.uk/812/ |
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