1,721,036 research outputs found
Integrating multi-receiver EMI measurements to characterize the soil-landscape around the school of gladiators, Carnuntum
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Kombinierte Oberflächen- und Untergrundprospektion mittels Punktwolken für geophysikalische archäologische Untersuchungen
Full text linkThe integration of diverse point cloud sources – such as Terrestrial Laserscanning (TLS), Image Based Modelling (IBM), and Ground Penetrating Radar (GPR) – enables the creation of comprehensive 3D models of archaeological sites, imaging both surface and subsurface structures. Each data type captures distinct information: TLS provides detailed geometry, photogrammetry offers texture and overall structure, and GPR reveals subsurface features. Merging these data sets into a unified point cloud improves the visualisation and facilitates the topographic correction of GPR data, GPR anomaly detection, and digital twin creation, which are essential for archaeological research and cultural heritage preservation. The proposed workflow optimises and georeferences TLS data while ensuring global consistency across multiple scans. Global reference is established by using Global Navigation Satellite System (GNSS) data of distinct features and airborne drone measurements. Comparisons to transform parameters using the geo-located IBM data are conducted and consequently preferred due to visual consistency. The resulting integrated 3D models not only enhance the understanding of the investigated cultural heritage sites but also improve the accuracy of subsurface and surface mapping by correlating overlapping structures from different sensing modalities. This project also demonstrates an automated framework, in which all data are treated as point clouds and merged following precise referencing. A dedicated C++ tool facilitates the optimisation process, and the integration is performed within a Geographic Information System (GIS) framework called Nubigon, suited for the handling of very large data sets. This type of system is pivotal in ensuring that both high-resolution surface details and subsurface anomalies are accurately represented, thereby supporting more effective conservation and research efforts. The custom developed tool is set to be published as open source software, therefore facilitating free access and the possibility of contribution by a broader user base. This encourages transparency and accessibility of software used for the specific purpose of aligning multiple point clouds and optimising the underlying pose graph. GPR data revealed subsurface structures and features within the manor grounds. Anomalies caused by buried walls and foundations of a suspected orangery were discovered beneath the meadow of a terrace adjacent to the building complex. These 3D point cloud data sets and contained structures have been jointely visualized using Nubigon, which overlays IBM surface data with GPR subsurface data to provide a comprehensive representation
Integrated Prospection Approaches for Archaeological Sites in the Alluvial Plain of “Cilicia Pedias”
No full textGeophysical Measurements on Glacial Soils: A Challenge in the Detection, Identification and Reconstruction of Archaeological Targets
Full text linkThe archaeological investigation of Bronze Age features in glacial soils in geophysical data is a great challenge and will be the focus of three distinct chapters of this thesis. Glacial soils are characterised by a high proportion of boulder stones but also by the occurrence of iron oxide concretions and are thus very heterogeneous. One of the challenges is to identify stony archaeological features in the stony environment. The first two chapters deal with the improvement of the detection and identification of archaeological features in radar and magnetic data. Subject of the investigations are burial mounds and their near surroundings. The third chapter attempts to reconstruct the shape and height of an almost eroded burial mound. Extensive geophysical measurement campaigns were carried out over Bronze Age sites in the region of northern Germany, with a strong focus on radar and magnetic measurements. To be able to estimate how much archaeological features are detected in the geophysical data the archaeological documentation was included. Soil analyses were used to estimate soil conditions with the help of numerical modelling. To estimate the height of the former mound geometric shapes, such as bell shape, cone, and spherical section were used. This study demonstrates that the detectability of stony archaeological features can be improved if the measurement campaign is conducted in the wet months, whereas the improved detectability of pit-like features will be improved if one measures in the drier months. The identification of archaeological features can be improved if one combines radar with magnetic data and by the development of a pattern recognition tool by additionally use the signal strength. The minimum height of the former burial mound could be determined, based on the usage of the ditch material from each phase and ranges between 2.1 m and 3.4 m
Marine and Limnic Archaeological Prospection with Geoelectrics and Ground-Penetrating Radar
Full text linkIn recent years, near-surface geophysical prospection of archaeological issues such as harbours in the littoral zone has gained increasing interest. So far, the two methods geoelectrics and ground-penetrating radar (GPR) have hardly been used for archaeological prospection in littoral zones. In addition, there is a lack of knowledge on the physical parameters of the materials to be prospected, including water-saturated, possibly weathered wood. In my thesis, I systematically investigate possible areas of application of the methods geoelectrics and GPR in the littoral zone. I investigate the methods’ limitations and conditions under which they can be used individually or as a complementary method to seismics. The targeted prospection of the material wood with the methods is treated in detail. First, application possibilities of geoelectrics were investigated. The method is suitable to resolve archaeological stone settings and groundwater upwelling areas. For survey measurements and geological issues, towed, floating electrode arrays are well suited. Submerged electrodes should be used for archaeological prospection. Next, the characteristics of GPR in water under field conditions were analysed. The methods’ penetration depth is almost independent of the antenna frequency and the presence of organic material in the water. An antenna array would have to be used for areal archaeological prospection with centimetre accuracy. The topic of the third part is “wood”. In order to evaluate possibilities of prospecting archaeological wooden objects such as shipwrecks with GPR and geoelectrics, the physical parameters of wood were determined experimentally and material contrasts were calculated. Both methods are suitable for the prospecting of wood in freshwater. The accurate evaluation of the methods in water environments allows them to be used in the future for well-defined research issues
Geophysical Prospection of Archaeological Sites on the Northern Peloponnese, Greece: Geological and Urban Challenges
Full text linkDespite 20 years of many developments, challenges remain for geophysical prospection of archaeological sites; two of these challenges are investigated in this thesis on case studies from the archaeological sites Aigeira and Sikyon; the geological setting and urban environments. These challenges can be overcome through various multi-method approaches depending on the region as shown on a series of case studies. However, this work also includes an extensive multi-method geophysical study focused on an enigmatic subsurface structure that could be interpreted as either prehistoric chamber tombs or complex, highly heterogeneous weathering patterns. This work demonstrates how shear-wave seismics and full-waveform inversion (FWI) can be used in archaeological prospecting to distinguish between different interpretive models. Since it is able to reveal a highly heterogeneous subsurface that is characterized by linear cracks on a decimeter scale. The second main case study highlights the challenge of a large-scale seismic prospection in an urban area. Even in the urban environment of modern Kiato, active seismic surveys in search of Sikyon's silted-up harbor basin have, in principle, been successfully conducted. Due to the too disturbing factors of the urban environment, passive ambient noise recording methods were tested. This thesis shows that the horizontal-to-vertical spectral ratio (HVSR) method can be used as a substitute of refraction seismics to map the depth of the first layer interface over large areas after establishing a relationship between the HVSR resonance frequency and refractor depth. The analysis of arrays (beamforming) of very small aperture arrays consisting of 9 stations proved capable to image the subsurface in similar resolution as does MASW. Hence, this method can be seen as a substitute to the Love-wave analysis for determining shear-wave velocities in an urban environment
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Mapping prehistoric wooden trackways using time domain induced polarisation
No full textTrackways are difficult to identify from conventional geophysical prospection data; they are narrow features, buried at often unknown depths and have little or no magnetic or electrical contrast with the surrounding organic peat. Recent case studies have shown promise for the detection of known wooden trackways located in waterlogged peat. The most suitable method for the assessment of large and dense wooden remains is Induced Polarisation (IP) a technique that exploits the polarisable properties of wood to create contrasts with the surrounding peat material. This case study presents work conducted at the Edercloon Bog Trackway Complex, Ireland
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