Analysis of the Effectiveness of Airborne Lidar Backscattered Laser Intensity

Lidar provides access to high resolution, high accuracy terrain information and as a secondary output a laser “image” of the land surface derived from measurements of the intensity of reflection of each backscattered laser pulse. Archaeological applications of Lidar have focused largely on its ability to provide a high resolution record of terrain variation, allowing the detection and mapping of subtle archaeological features mapping of fluvial geomorphology and its unique ability to penetrate vegetation cover to map underlying archaeological earthworks. Backscattered laser intensity measurements have largely escaped attention and little or no work has been undertaken to investigate intensity, which until now has been largely ignored both by archaeologists.

This research explores the application of airborne lidar intensity for geoarchaeological prospection in river valley floors by examining the factors influencing the lidar intensity record and exploring topographic and intensity data for a number of geoarchaeological test sites in the Trent Valley of the midlands of England.

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Monitoring Fragile Upland Landscapes: The Application of Airborne Lidar

This research investigated the potential of airborne lidar for recording and monitoring erosion levels in environmentally fragile upland landscapes, using an area of the Brecon Beacons National Park as a case study. Upland areas contain a rich variety of natural and cultural resources that are increasingly endangered through factors such as insensitive land-use practices, improvements in recreational access and climate change. Airborne lidar provides a highly detailed record of microtopography, in this example at a resolution of 0.5m with a vertical accuracy of c.0.15m and the ability to differentiate elevation changes to within 1-2cm. The technique therefore allows the rapid and cost-effective recording of the nature and extent of erosion at a landscape scale, with the results of this analysis recording over 46 kilometres of path erosion within a 3.8 km² area. The technique also provides the ability to highlight particular areas of risk, such as extensive braided erosion around path intersections and damage to protected SSSI habitats, providing a snapshot record of erosion at a particular point in time and an invaluable source of information for conservationists and policy-makers.

3D View of a Roman Marching Camp

Airborne Lidar And The Historic Environment

Airborne lidar has gradually assumed a place as part of the toolkit of remote sensing techniques available to archaeologists interested in landscape studies, although its use for the enhancement of historic environment records (HER) is in its infancy. The production and maintenance of HER is a labour intensive, costly process, challenging the resources allocated to the historic environment by local and national government. Changes in the legislation affecting scheduled ancient monuments and listed buildings proposed by central government will have a knock-on impact on HER records, for the first time making it a statutory responsibility of local authorities to maintain an authoritative HER and broadening the remit of those records.

This research investigated the potential of airborne lidar elevation data to enhance historic environment records through providing a rapid, landscape-scale record of upstanding archaeological earthworks. A 25km section of the River Dove Valley on the Derbyshire/Staffordshire border in the midlands of England was examined, and the results of analysis of lidar data compared with the existing HER for the study area and with control information obtained from a rapid assessment of vertical aerial photography.

This analysis demonstrates that lidar has the potential to provide significant extra information on cultural heritage, is a cost effective technique, in some instances representing a better value return than analysis of standard air-photography. While this example is based on the British archaeological record, lidar is increasingly available globally and the approach examined has significant generic implications for cultural resource management internationally.

Qatar Remote Sensing Project [PDF]

Predictive Modeling Of Multi-Period Geoarchaeological Resources At A River Confluence

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A Whole-site First-assessment Toolkit for combined Mineral Resource and Archaeological assessment in Sand and Gravel deposits

Ground investigations are essential components of site assessment for both mineral resources, and archaeological remains. The techniques used for both mineral and archaeological assessment are often similar. Since investigations for both purposes must be performed in areas of potential mineral resource, and there is considerable overlap between them, there are potential benefits to mineral operators, heritage protection, and the planning process, in developing a systematic integrated approach to these investigations.

This research examined the synergies between site investigation for mineral resource and archaeological purposes through the investigation of two example sites, at Sturton-le-Steeple and Shelford, both in the Trent valley. Both sites combine the presence of a known aggregate resource with known archaeological remains, as well as being part of a populated and worked landscape, with issues such as soil quality, hydrogeology and bio-diversity to be considered.

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Airborne Remote Sensing of Alluvial Environments

This research investigates the potential of multispectral methods of airborne remote sensing for geoarchaeological prospection in river valleys, specifically the archaeologically rich, well-documented aggregate landscape of the middle Trent Valley in the East Midlands of England. The paper reviews the systematic examination of Daedalus 1268 Airborne Thematic Mapper and Compact Airborne Spectrographic Imager multispectral data. Data from a single flight along the Trent Valley in 1996 were subject to a comprehensive suit of analytical techniques including the calculation of vegetation indices and multivariate analysis. The results suggest that both ATM and CASI data have great potential for detecting and characterising anthropogenic and geoarchaeological features. Vegetation indices relying on ratios or red to infrared reflectance were particularly effective at highlighting cropmarks, in some cases revealing crop variation not apparent in the visible spectrum.

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Assessing the Geoarchaeological Development of Catchment Tributaries and their Impact

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